15bb6a25fSPoul-Henning Kamp<?xml version="1.0" encoding="iso-8859-1"?> 25bb6a25fSPoul-Henning Kamp<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 35bb6a25fSPoul-Henning Kamp "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 45bb6a25fSPoul-Henning Kamp<html> 55bb6a25fSPoul-Henning Kamp<head> 6cc68614dSXin LI<!-- 7cc68614dSXin LI __ __ _ 8cc68614dSXin LI ___\ \/ /_ __ __ _| |_ 9cc68614dSXin LI / _ \\ /| '_ \ / _` | __| 10cc68614dSXin LI | __// \| |_) | (_| | |_ 11cc68614dSXin LI \___/_/\_\ .__/ \__,_|\__| 12cc68614dSXin LI |_| XML parser 13cc68614dSXin LI 14cc68614dSXin LI Copyright (c) 2000 Clark Cooper <coopercc@users.sourceforge.net> 15cc68614dSXin LI Copyright (c) 2000-2004 Fred L. Drake, Jr. <fdrake@users.sourceforge.net> 16cc68614dSXin LI Copyright (c) 2002-2012 Karl Waclawek <karl@waclawek.net> 17cc68614dSXin LI Copyright (c) 2017-2022 Sebastian Pipping <sebastian@pipping.org> 18cc68614dSXin LI Copyright (c) 2017 Jakub Wilk <jwilk@jwilk.net> 19cc68614dSXin LI Copyright (c) 2021 Tomas Korbar <tkorbar@redhat.com> 20cc68614dSXin LI Copyright (c) 2021 Nicolas Cavallari <nicolas.cavallari@green-communications.fr> 217ed8e142SXin LI Copyright (c) 2022 Thijs Schreijer <thijs@thijsschreijer.nl> 22cc68614dSXin LI Licensed under the MIT license: 23cc68614dSXin LI 24cc68614dSXin LI Permission is hereby granted, free of charge, to any person obtaining 25cc68614dSXin LI a copy of this software and associated documentation files (the 26cc68614dSXin LI "Software"), to deal in the Software without restriction, including 27cc68614dSXin LI without limitation the rights to use, copy, modify, merge, publish, 28cc68614dSXin LI distribute, sublicense, and/or sell copies of the Software, and to permit 29cc68614dSXin LI persons to whom the Software is furnished to do so, subject to the 30cc68614dSXin LI following conditions: 31cc68614dSXin LI 32cc68614dSXin LI The above copyright notice and this permission notice shall be included 33cc68614dSXin LI in all copies or substantial portions of the Software. 34cc68614dSXin LI 35cc68614dSXin LI THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 36cc68614dSXin LI EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 37cc68614dSXin LI MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN 38cc68614dSXin LI NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 39cc68614dSXin LI DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 40cc68614dSXin LI OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 41cc68614dSXin LI USE OR OTHER DEALINGS IN THE SOFTWARE. 42cc68614dSXin LI--> 435bb6a25fSPoul-Henning Kamp <title>Expat XML Parser</title> 445bb6a25fSPoul-Henning Kamp <meta name="author" content="Clark Cooper, coopercc@netheaven.com" /> 455bb6a25fSPoul-Henning Kamp <meta http-equiv="Content-Style-Type" content="text/css" /> 46cc68614dSXin LI <link href="ok.min.css" rel="stylesheet" type="text/css" /> 475bb6a25fSPoul-Henning Kamp <link href="style.css" rel="stylesheet" type="text/css" /> 485bb6a25fSPoul-Henning Kamp</head> 495bb6a25fSPoul-Henning Kamp<body> 50cc68614dSXin LI <div> 51cc68614dSXin LI <h1> 52cc68614dSXin LI The Expat XML Parser 53*71f0c44aSXin LI <small>Release 2.4.9</small> 54cc68614dSXin LI </h1> 55cc68614dSXin LI </div> 56220ed979SColeman Kane<div class="content"> 575bb6a25fSPoul-Henning Kamp 585bb6a25fSPoul-Henning Kamp<p>Expat is a library, written in C, for parsing XML documents. It's 595bb6a25fSPoul-Henning Kampthe underlying XML parser for the open source Mozilla project, Perl's 605bb6a25fSPoul-Henning Kamp<code>XML::Parser</code>, Python's <code>xml.parsers.expat</code>, and 615bb6a25fSPoul-Henning Kampother open-source XML parsers.</p> 625bb6a25fSPoul-Henning Kamp 635bb6a25fSPoul-Henning Kamp<p>This library is the creation of James Clark, who's also given us 640a48773fSEric van Gyzengroff (an nroff look-alike), Jade (an implementation of ISO's DSSSL 655bb6a25fSPoul-Henning Kampstylesheet language for SGML), XP (a Java XML parser package), XT (a 665bb6a25fSPoul-Henning KampJava XSL engine). James was also the technical lead on the XML 675bb6a25fSPoul-Henning KampWorking Group at W3C that produced the XML specification.</p> 685bb6a25fSPoul-Henning Kamp 695bb6a25fSPoul-Henning Kamp<p>This is free software, licensed under the <a 705bb6a25fSPoul-Henning Kamphref="../COPYING">MIT/X Consortium license</a>. You may download it 715bb6a25fSPoul-Henning Kampfrom <a href="http://www.libexpat.org/">the Expat home page</a>. 725bb6a25fSPoul-Henning Kamp</p> 735bb6a25fSPoul-Henning Kamp 74220ed979SColeman Kane<p>The bulk of this document was originally commissioned as an article 75220ed979SColeman Kaneby <a href="http://www.xml.com/">XML.com</a>. They graciously allowed 76220ed979SColeman KaneClark Cooper to retain copyright and to distribute it with Expat. 77220ed979SColeman KaneThis version has been substantially extended to include documentation 78220ed979SColeman Kaneon features which have been added since the original article was 79220ed979SColeman Kanepublished, and additional information on using the original 80220ed979SColeman Kaneinterface.</p> 815bb6a25fSPoul-Henning Kamp 825bb6a25fSPoul-Henning Kamp<hr /> 835bb6a25fSPoul-Henning Kamp<h2>Table of Contents</h2> 845bb6a25fSPoul-Henning Kamp<ul> 855bb6a25fSPoul-Henning Kamp <li><a href="#overview">Overview</a></li> 865bb6a25fSPoul-Henning Kamp <li><a href="#building">Building and Installing</a></li> 875bb6a25fSPoul-Henning Kamp <li><a href="#using">Using Expat</a></li> 885bb6a25fSPoul-Henning Kamp <li><a href="#reference">Reference</a> 895bb6a25fSPoul-Henning Kamp <ul> 905bb6a25fSPoul-Henning Kamp <li><a href="#creation">Parser Creation Functions</a> 915bb6a25fSPoul-Henning Kamp <ul> 925bb6a25fSPoul-Henning Kamp <li><a href="#XML_ParserCreate">XML_ParserCreate</a></li> 935bb6a25fSPoul-Henning Kamp <li><a href="#XML_ParserCreateNS">XML_ParserCreateNS</a></li> 945bb6a25fSPoul-Henning Kamp <li><a href="#XML_ParserCreate_MM">XML_ParserCreate_MM</a></li> 955bb6a25fSPoul-Henning Kamp <li><a href="#XML_ExternalEntityParserCreate">XML_ExternalEntityParserCreate</a></li> 965bb6a25fSPoul-Henning Kamp <li><a href="#XML_ParserFree">XML_ParserFree</a></li> 975bb6a25fSPoul-Henning Kamp <li><a href="#XML_ParserReset">XML_ParserReset</a></li> 985bb6a25fSPoul-Henning Kamp </ul> 995bb6a25fSPoul-Henning Kamp </li> 1005bb6a25fSPoul-Henning Kamp <li><a href="#parsing">Parsing Functions</a> 1015bb6a25fSPoul-Henning Kamp <ul> 1025bb6a25fSPoul-Henning Kamp <li><a href="#XML_Parse">XML_Parse</a></li> 1035bb6a25fSPoul-Henning Kamp <li><a href="#XML_ParseBuffer">XML_ParseBuffer</a></li> 1045bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetBuffer">XML_GetBuffer</a></li> 105220ed979SColeman Kane <li><a href="#XML_StopParser">XML_StopParser</a></li> 106220ed979SColeman Kane <li><a href="#XML_ResumeParser">XML_ResumeParser</a></li> 107220ed979SColeman Kane <li><a href="#XML_GetParsingStatus">XML_GetParsingStatus</a></li> 1085bb6a25fSPoul-Henning Kamp </ul> 1095bb6a25fSPoul-Henning Kamp </li> 1105bb6a25fSPoul-Henning Kamp <li><a href="#setting">Handler Setting Functions</a> 1115bb6a25fSPoul-Henning Kamp <ul> 1125bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetStartElementHandler">XML_SetStartElementHandler</a></li> 1135bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetEndElementHandler">XML_SetEndElementHandler</a></li> 1145bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetElementHandler">XML_SetElementHandler</a></li> 1155bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetCharacterDataHandler">XML_SetCharacterDataHandler</a></li> 1165bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetProcessingInstructionHandler">XML_SetProcessingInstructionHandler</a></li> 1175bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetCommentHandler">XML_SetCommentHandler</a></li> 1185bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetStartCdataSectionHandler">XML_SetStartCdataSectionHandler</a></li> 1195bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetEndCdataSectionHandler">XML_SetEndCdataSectionHandler</a></li> 1205bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetCdataSectionHandler">XML_SetCdataSectionHandler</a></li> 1215bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetDefaultHandler">XML_SetDefaultHandler</a></li> 1225bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetDefaultHandlerExpand">XML_SetDefaultHandlerExpand</a></li> 1235bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetExternalEntityRefHandler">XML_SetExternalEntityRefHandler</a></li> 124220ed979SColeman Kane <li><a href="#XML_SetExternalEntityRefHandlerArg">XML_SetExternalEntityRefHandlerArg</a></li> 1255bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetSkippedEntityHandler">XML_SetSkippedEntityHandler</a></li> 1265bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetUnknownEncodingHandler">XML_SetUnknownEncodingHandler</a></li> 1275bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetStartNamespaceDeclHandler">XML_SetStartNamespaceDeclHandler</a></li> 1285bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetEndNamespaceDeclHandler">XML_SetEndNamespaceDeclHandler</a></li> 1295bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetNamespaceDeclHandler">XML_SetNamespaceDeclHandler</a></li> 1305bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetXmlDeclHandler">XML_SetXmlDeclHandler</a></li> 1315bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetStartDoctypeDeclHandler">XML_SetStartDoctypeDeclHandler</a></li> 1325bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetEndDoctypeDeclHandler">XML_SetEndDoctypeDeclHandler</a></li> 1335bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetDoctypeDeclHandler">XML_SetDoctypeDeclHandler</a></li> 1345bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetElementDeclHandler">XML_SetElementDeclHandler</a></li> 1355bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetAttlistDeclHandler">XML_SetAttlistDeclHandler</a></li> 1365bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetEntityDeclHandler">XML_SetEntityDeclHandler</a></li> 1375bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetUnparsedEntityDeclHandler">XML_SetUnparsedEntityDeclHandler</a></li> 1385bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetNotationDeclHandler">XML_SetNotationDeclHandler</a></li> 1395bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetNotStandaloneHandler">XML_SetNotStandaloneHandler</a></li> 1405bb6a25fSPoul-Henning Kamp </ul> 1415bb6a25fSPoul-Henning Kamp </li> 1425bb6a25fSPoul-Henning Kamp <li><a href="#position">Parse Position and Error Reporting Functions</a> 1435bb6a25fSPoul-Henning Kamp <ul> 1445bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetErrorCode">XML_GetErrorCode</a></li> 1455bb6a25fSPoul-Henning Kamp <li><a href="#XML_ErrorString">XML_ErrorString</a></li> 1465bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetCurrentByteIndex">XML_GetCurrentByteIndex</a></li> 1475bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetCurrentLineNumber">XML_GetCurrentLineNumber</a></li> 1485bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetCurrentColumnNumber">XML_GetCurrentColumnNumber</a></li> 1495bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetCurrentByteCount">XML_GetCurrentByteCount</a></li> 1505bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetInputContext">XML_GetInputContext</a></li> 1515bb6a25fSPoul-Henning Kamp </ul> 1525bb6a25fSPoul-Henning Kamp </li> 153cc68614dSXin LI <li> 154cc68614dSXin LI <a href="#billion-laughs">Billion Laughs Attack Protection</a> 155cc68614dSXin LI <ul> 156cc68614dSXin LI <li><a href="#XML_SetBillionLaughsAttackProtectionMaximumAmplification">XML_SetBillionLaughsAttackProtectionMaximumAmplification</a></li> 157cc68614dSXin LI <li><a href="#XML_SetBillionLaughsAttackProtectionActivationThreshold">XML_SetBillionLaughsAttackProtectionActivationThreshold</a></li> 158cc68614dSXin LI </ul> 159cc68614dSXin LI </li> 1605bb6a25fSPoul-Henning Kamp <li><a href="#miscellaneous">Miscellaneous Functions</a> 1615bb6a25fSPoul-Henning Kamp <ul> 1625bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetUserData">XML_SetUserData</a></li> 1635bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetUserData">XML_GetUserData</a></li> 1645bb6a25fSPoul-Henning Kamp <li><a href="#XML_UseParserAsHandlerArg">XML_UseParserAsHandlerArg</a></li> 1655bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetBase">XML_SetBase</a></li> 1665bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetBase">XML_GetBase</a></li> 1675bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetSpecifiedAttributeCount">XML_GetSpecifiedAttributeCount</a></li> 1685bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetIdAttributeIndex">XML_GetIdAttributeIndex</a></li> 169e3466a89SXin LI <li><a href="#XML_GetAttributeInfo">XML_GetAttributeInfo</a></li> 1705bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetEncoding">XML_SetEncoding</a></li> 1715bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetParamEntityParsing">XML_SetParamEntityParsing</a></li> 172e3466a89SXin LI <li><a href="#XML_SetHashSalt">XML_SetHashSalt</a></li> 1735bb6a25fSPoul-Henning Kamp <li><a href="#XML_UseForeignDTD">XML_UseForeignDTD</a></li> 1745bb6a25fSPoul-Henning Kamp <li><a href="#XML_SetReturnNSTriplet">XML_SetReturnNSTriplet</a></li> 1755bb6a25fSPoul-Henning Kamp <li><a href="#XML_DefaultCurrent">XML_DefaultCurrent</a></li> 1765bb6a25fSPoul-Henning Kamp <li><a href="#XML_ExpatVersion">XML_ExpatVersion</a></li> 1775bb6a25fSPoul-Henning Kamp <li><a href="#XML_ExpatVersionInfo">XML_ExpatVersionInfo</a></li> 1785bb6a25fSPoul-Henning Kamp <li><a href="#XML_GetFeatureList">XML_GetFeatureList</a></li> 179220ed979SColeman Kane <li><a href="#XML_FreeContentModel">XML_FreeContentModel</a></li> 180220ed979SColeman Kane <li><a href="#XML_MemMalloc">XML_MemMalloc</a></li> 181220ed979SColeman Kane <li><a href="#XML_MemRealloc">XML_MemRealloc</a></li> 182220ed979SColeman Kane <li><a href="#XML_MemFree">XML_MemFree</a></li> 1835bb6a25fSPoul-Henning Kamp </ul> 1845bb6a25fSPoul-Henning Kamp </li> 1855bb6a25fSPoul-Henning Kamp </ul> 1865bb6a25fSPoul-Henning Kamp </li> 1875bb6a25fSPoul-Henning Kamp</ul> 1885bb6a25fSPoul-Henning Kamp 1895bb6a25fSPoul-Henning Kamp<hr /> 1905bb6a25fSPoul-Henning Kamp<h2><a name="overview">Overview</a></h2> 1915bb6a25fSPoul-Henning Kamp 1925bb6a25fSPoul-Henning Kamp<p>Expat is a stream-oriented parser. You register callback (or 1935bb6a25fSPoul-Henning Kamphandler) functions with the parser and then start feeding it the 1945bb6a25fSPoul-Henning Kampdocument. As the parser recognizes parts of the document, it will 1955bb6a25fSPoul-Henning Kampcall the appropriate handler for that part (if you've registered one.) 1965bb6a25fSPoul-Henning KampThe document is fed to the parser in pieces, so you can start parsing 1975bb6a25fSPoul-Henning Kampbefore you have all the document. This also allows you to parse really 1985bb6a25fSPoul-Henning Kamphuge documents that won't fit into memory.</p> 1995bb6a25fSPoul-Henning Kamp 2005bb6a25fSPoul-Henning Kamp<p>Expat can be intimidating due to the many kinds of handlers and 2015bb6a25fSPoul-Henning Kampoptions you can set. But you only need to learn four functions in 2025bb6a25fSPoul-Henning Kamporder to do 90% of what you'll want to do with it:</p> 2035bb6a25fSPoul-Henning Kamp 2045bb6a25fSPoul-Henning Kamp<dl> 2055bb6a25fSPoul-Henning Kamp 2065bb6a25fSPoul-Henning Kamp<dt><code><a href= "#XML_ParserCreate" 2075bb6a25fSPoul-Henning Kamp >XML_ParserCreate</a></code></dt> 2085bb6a25fSPoul-Henning Kamp <dd>Create a new parser object.</dd> 2095bb6a25fSPoul-Henning Kamp 2105bb6a25fSPoul-Henning Kamp<dt><code><a href= "#XML_SetElementHandler" 2115bb6a25fSPoul-Henning Kamp >XML_SetElementHandler</a></code></dt> 2125bb6a25fSPoul-Henning Kamp <dd>Set handlers for start and end tags.</dd> 2135bb6a25fSPoul-Henning Kamp 2145bb6a25fSPoul-Henning Kamp<dt><code><a href= "#XML_SetCharacterDataHandler" 2155bb6a25fSPoul-Henning Kamp >XML_SetCharacterDataHandler</a></code></dt> 2165bb6a25fSPoul-Henning Kamp <dd>Set handler for text.</dd> 2175bb6a25fSPoul-Henning Kamp 2185bb6a25fSPoul-Henning Kamp<dt><code><a href= "#XML_Parse" 2195bb6a25fSPoul-Henning Kamp >XML_Parse</a></code></dt> 2205bb6a25fSPoul-Henning Kamp <dd>Pass a buffer full of document to the parser</dd> 2215bb6a25fSPoul-Henning Kamp</dl> 2225bb6a25fSPoul-Henning Kamp 2235bb6a25fSPoul-Henning Kamp<p>These functions and others are described in the <a 2245bb6a25fSPoul-Henning Kamphref="#reference">reference</a> part of this document. The reference 2255bb6a25fSPoul-Henning Kampsection also describes in detail the parameters passed to the 2265bb6a25fSPoul-Henning Kampdifferent types of handlers.</p> 2275bb6a25fSPoul-Henning Kamp 2285bb6a25fSPoul-Henning Kamp<p>Let's look at a very simple example program that only uses 3 of the 2295bb6a25fSPoul-Henning Kampabove functions (it doesn't need to set a character handler.) The 2305bb6a25fSPoul-Henning Kampprogram <a href="../examples/outline.c">outline.c</a> prints an 2315bb6a25fSPoul-Henning Kampelement outline, indenting child elements to distinguish them from the 2325bb6a25fSPoul-Henning Kampparent element that contains them. The start handler does all the 2335bb6a25fSPoul-Henning Kampwork. It prints two indenting spaces for every level of ancestor 2345bb6a25fSPoul-Henning Kampelements, then it prints the element and attribute 2355bb6a25fSPoul-Henning Kampinformation. Finally it increments the global <code>Depth</code> 2365bb6a25fSPoul-Henning Kampvariable.</p> 2375bb6a25fSPoul-Henning Kamp 2385bb6a25fSPoul-Henning Kamp<pre class="eg"> 2395bb6a25fSPoul-Henning Kampint Depth; 2405bb6a25fSPoul-Henning Kamp 241220ed979SColeman Kanevoid XMLCALL 2425bb6a25fSPoul-Henning Kampstart(void *data, const char *el, const char **attr) { 2435bb6a25fSPoul-Henning Kamp int i; 2445bb6a25fSPoul-Henning Kamp 2455bb6a25fSPoul-Henning Kamp for (i = 0; i < Depth; i++) 2465bb6a25fSPoul-Henning Kamp printf(" "); 2475bb6a25fSPoul-Henning Kamp 2485bb6a25fSPoul-Henning Kamp printf("%s", el); 2495bb6a25fSPoul-Henning Kamp 2505bb6a25fSPoul-Henning Kamp for (i = 0; attr[i]; i += 2) { 2515bb6a25fSPoul-Henning Kamp printf(" %s='%s'", attr[i], attr[i + 1]); 2525bb6a25fSPoul-Henning Kamp } 2535bb6a25fSPoul-Henning Kamp 2545bb6a25fSPoul-Henning Kamp printf("\n"); 2555bb6a25fSPoul-Henning Kamp Depth++; 2565bb6a25fSPoul-Henning Kamp} /* End of start handler */ 2575bb6a25fSPoul-Henning Kamp</pre> 2585bb6a25fSPoul-Henning Kamp 2595bb6a25fSPoul-Henning Kamp<p>The end tag simply does the bookkeeping work of decrementing 2605bb6a25fSPoul-Henning Kamp<code>Depth</code>.</p> 2615bb6a25fSPoul-Henning Kamp<pre class="eg"> 262220ed979SColeman Kanevoid XMLCALL 2635bb6a25fSPoul-Henning Kampend(void *data, const char *el) { 2645bb6a25fSPoul-Henning Kamp Depth--; 2655bb6a25fSPoul-Henning Kamp} /* End of end handler */ 2665bb6a25fSPoul-Henning Kamp</pre> 2675bb6a25fSPoul-Henning Kamp 268220ed979SColeman Kane<p>Note the <code>XMLCALL</code> annotation used for the callbacks. 269220ed979SColeman KaneThis is used to ensure that the Expat and the callbacks are using the 270220ed979SColeman Kanesame calling convention in case the compiler options used for Expat 271220ed979SColeman Kaneitself and the client code are different. Expat tries not to care 272220ed979SColeman Kanewhat the default calling convention is, though it may require that it 273220ed979SColeman Kanebe compiled with a default convention of "cdecl" on some platforms. 274220ed979SColeman KaneFor code which uses Expat, however, the calling convention is 275220ed979SColeman Kanespecified by the <code>XMLCALL</code> annotation on most platforms; 276220ed979SColeman Kanecallbacks should be defined using this annotation.</p> 277220ed979SColeman Kane 278220ed979SColeman Kane<p>The <code>XMLCALL</code> annotation was added in Expat 1.95.7, but 279220ed979SColeman Kaneexisting working Expat applications don't need to add it (since they 280220ed979SColeman Kaneare already using the "cdecl" calling convention, or they wouldn't be 281220ed979SColeman Kaneworking). The annotation is only needed if the default calling 282220ed979SColeman Kaneconvention may be something other than "cdecl". To use the annotation 283220ed979SColeman Kanesafely with older versions of Expat, you can conditionally define it 284220ed979SColeman Kane<em>after</em> including Expat's header file:</p> 285220ed979SColeman Kane 286220ed979SColeman Kane<pre class="eg"> 287220ed979SColeman Kane#include <expat.h> 288220ed979SColeman Kane 289220ed979SColeman Kane#ifndef XMLCALL 290220ed979SColeman Kane#if defined(_MSC_EXTENSIONS) && !defined(__BEOS__) && !defined(__CYGWIN__) 291220ed979SColeman Kane#define XMLCALL __cdecl 292220ed979SColeman Kane#elif defined(__GNUC__) 293220ed979SColeman Kane#define XMLCALL __attribute__((cdecl)) 294220ed979SColeman Kane#else 295220ed979SColeman Kane#define XMLCALL 296220ed979SColeman Kane#endif 297220ed979SColeman Kane#endif 298220ed979SColeman Kane</pre> 299220ed979SColeman Kane 3005bb6a25fSPoul-Henning Kamp<p>After creating the parser, the main program just has the job of 3015bb6a25fSPoul-Henning Kampshoveling the document to the parser so that it can do its work.</p> 3025bb6a25fSPoul-Henning Kamp 3035bb6a25fSPoul-Henning Kamp<hr /> 3045bb6a25fSPoul-Henning Kamp<h2><a name="building">Building and Installing Expat</a></h2> 3055bb6a25fSPoul-Henning Kamp 3065bb6a25fSPoul-Henning Kamp<p>The Expat distribution comes as a compressed (with GNU gzip) tar 3075bb6a25fSPoul-Henning Kampfile. You may download the latest version from <a href= 3085bb6a25fSPoul-Henning Kamp"http://sourceforge.net/projects/expat/" >Source Forge</a>. After 3095bb6a25fSPoul-Henning Kampunpacking this, cd into the directory. Then follow either the Win32 3105bb6a25fSPoul-Henning Kampdirections or Unix directions below.</p> 3115bb6a25fSPoul-Henning Kamp 3125bb6a25fSPoul-Henning Kamp<h3>Building under Win32</h3> 3135bb6a25fSPoul-Henning Kamp 3145bb6a25fSPoul-Henning Kamp<p>If you're using the GNU compiler under cygwin, follow the Unix 3155bb6a25fSPoul-Henning Kampdirections in the next section. Otherwise if you have Microsoft's 3166b2c1e49SXin LIDeveloper Studio installed, 3176b2c1e49SXin LIyou can use CMake to generate a <code>.sln</code> file, e.g. 3186b2c1e49SXin LI<code> 3196b2c1e49SXin LIcmake -G"Visual Studio 15 2017" -DCMAKE_BUILD_TYPE=RelWithDebInfo . 3206b2c1e49SXin LI</code>, and build Expat using <code>msbuild /m expat.sln</code> after.</p> 3215bb6a25fSPoul-Henning Kamp 3225bb6a25fSPoul-Henning Kamp<p>Alternatively, you may download the Win32 binary package that 3235bb6a25fSPoul-Henning Kampcontains the "expat.h" include file and a pre-built DLL.</p> 3245bb6a25fSPoul-Henning Kamp 3255bb6a25fSPoul-Henning Kamp<h3>Building under Unix (or GNU)</h3> 3265bb6a25fSPoul-Henning Kamp 3275bb6a25fSPoul-Henning Kamp<p>First you'll need to run the configure shell script in order to 3285bb6a25fSPoul-Henning Kampconfigure the Makefiles and headers for your system.</p> 3295bb6a25fSPoul-Henning Kamp 3305bb6a25fSPoul-Henning Kamp<p>If you're happy with all the defaults that configure picks for you, 3315bb6a25fSPoul-Henning Kampand you have permission on your system to install into /usr/local, you 3325bb6a25fSPoul-Henning Kampcan install Expat with this sequence of commands:</p> 3335bb6a25fSPoul-Henning Kamp 3345bb6a25fSPoul-Henning Kamp<pre class="eg"> 3355bb6a25fSPoul-Henning Kamp./configure 3365bb6a25fSPoul-Henning Kampmake 3375bb6a25fSPoul-Henning Kampmake install 3385bb6a25fSPoul-Henning Kamp</pre> 3395bb6a25fSPoul-Henning Kamp 3405bb6a25fSPoul-Henning Kamp<p>There are some options that you can provide to this script, but the 3415bb6a25fSPoul-Henning Kamponly one we'll mention here is the <code>--prefix</code> option. You 3425bb6a25fSPoul-Henning Kampcan find out all the options available by running configure with just 3435bb6a25fSPoul-Henning Kampthe <code>--help</code> option.</p> 3445bb6a25fSPoul-Henning Kamp 3455bb6a25fSPoul-Henning Kamp<p>By default, the configure script sets things up so that the library 3465bb6a25fSPoul-Henning Kampgets installed in <code>/usr/local/lib</code> and the associated 3475bb6a25fSPoul-Henning Kampheader file in <code>/usr/local/include</code>. But if you were to 3485bb6a25fSPoul-Henning Kampgive the option, <code>--prefix=/home/me/mystuff</code>, then the 3495bb6a25fSPoul-Henning Kamplibrary and header would get installed in 3505bb6a25fSPoul-Henning Kamp<code>/home/me/mystuff/lib</code> and 3515bb6a25fSPoul-Henning Kamp<code>/home/me/mystuff/include</code> respectively.</p> 3525bb6a25fSPoul-Henning Kamp 353220ed979SColeman Kane<h3>Configuring Expat Using the Pre-Processor</h3> 354220ed979SColeman Kane 355220ed979SColeman Kane<p>Expat's feature set can be configured using a small number of 356220ed979SColeman Kanepre-processor definitions. The definition of this symbols does not 357220ed979SColeman Kaneaffect the set of entry points for Expat, only the behavior of the API 358220ed979SColeman Kaneand the definition of character types in the case of 359220ed979SColeman Kane<code>XML_UNICODE_WCHAR_T</code>. The symbols are:</p> 360220ed979SColeman Kane 361220ed979SColeman Kane<dl class="cpp-symbols"> 362220ed979SColeman Kane<dt>XML_DTD</dt> 363220ed979SColeman Kane<dd>Include support for using and reporting DTD-based content. If 364220ed979SColeman Kanethis is defined, default attribute values from an external DTD subset 365220ed979SColeman Kaneare reported and attribute value normalization occurs based on the 366220ed979SColeman Kanetype of attributes defined in the external subset. Without 367220ed979SColeman Kanethis, Expat has a smaller memory footprint and can be faster, but will 368*71f0c44aSXin LInot load external entities or process conditional sections. If defined, makes 369*71f0c44aSXin LIthe functions <code><a 370*71f0c44aSXin LIhref="#XML_SetBillionLaughsAttackProtectionMaximumAmplification"> 371*71f0c44aSXin LIXML_SetBillionLaughsAttackProtectionMaximumAmplification</a></code> and <code> 372*71f0c44aSXin LI<a href="#XML_SetBillionLaughsAttackProtectionActivationThreshold"> 373*71f0c44aSXin LIXML_SetBillionLaughsAttackProtectionActivationThreshold</a></code> available.</dd> 374220ed979SColeman Kane 375220ed979SColeman Kane<dt>XML_NS</dt> 376220ed979SColeman Kane<dd>When defined, support for the <cite><a href= 377220ed979SColeman Kane"http://www.w3.org/TR/REC-xml-names/" >Namespaces in XML</a></cite> 378220ed979SColeman Kanespecification is included.</dd> 379220ed979SColeman Kane 380220ed979SColeman Kane<dt>XML_UNICODE</dt> 381220ed979SColeman Kane<dd>When defined, character data reported to the application is 382220ed979SColeman Kaneencoded in UTF-16 using wide characters of the type 383220ed979SColeman Kane<code>XML_Char</code>. This is implied if 384220ed979SColeman Kane<code>XML_UNICODE_WCHAR_T</code> is defined.</dd> 385220ed979SColeman Kane 386220ed979SColeman Kane<dt>XML_UNICODE_WCHAR_T</dt> 387220ed979SColeman Kane<dd>If defined, causes the <code>XML_Char</code> character type to be 388220ed979SColeman Kanedefined using the <code>wchar_t</code> type; otherwise, <code>unsigned 389220ed979SColeman Kaneshort</code> is used. Defining this implies 390220ed979SColeman Kane<code>XML_UNICODE</code>.</dd> 391220ed979SColeman Kane 392220ed979SColeman Kane<dt>XML_LARGE_SIZE</dt> 393220ed979SColeman Kane<dd>If defined, causes the <code>XML_Size</code> and <code>XML_Index</code> 394220ed979SColeman Kaneinteger types to be at least 64 bits in size. This is intended to support 395220ed979SColeman Kaneprocessing of very large input streams, where the return values of 396220ed979SColeman Kane<code><a href="#XML_GetCurrentByteIndex" >XML_GetCurrentByteIndex</a></code>, 397220ed979SColeman Kane<code><a href="#XML_GetCurrentLineNumber" >XML_GetCurrentLineNumber</a></code> and 398220ed979SColeman Kane<code><a href="#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code> 399220ed979SColeman Kanecould overflow. It may not be supported by all compilers, and is turned 400220ed979SColeman Kaneoff by default.</dd> 401220ed979SColeman Kane 402220ed979SColeman Kane<dt>XML_CONTEXT_BYTES</dt> 403220ed979SColeman Kane<dd>The number of input bytes of markup context which the parser will 404220ed979SColeman Kaneensure are available for reporting via <code><a href= 405220ed979SColeman Kane"#XML_GetInputContext" >XML_GetInputContext</a></code>. This is 4060a48773fSEric van Gyzennormally set to 1024, and must be set to a positive integer. If this 407220ed979SColeman Kaneis not defined, the input context will not be available and <code><a 408220ed979SColeman Kanehref= "#XML_GetInputContext" >XML_GetInputContext</a></code> will 409220ed979SColeman Kanealways report NULL. Without this, Expat has a smaller memory 410220ed979SColeman Kanefootprint and can be faster.</dd> 411220ed979SColeman Kane 412220ed979SColeman Kane<dt>XML_STATIC</dt> 413220ed979SColeman Kane<dd>On Windows, this should be set if Expat is going to be linked 414220ed979SColeman Kanestatically with the code that calls it; this is required to get all 415220ed979SColeman Kanethe right MSVC magic annotations correct. This is ignored on other 416220ed979SColeman Kaneplatforms.</dd> 417e3466a89SXin LI 418e3466a89SXin LI<dt>XML_ATTR_INFO</dt> 4190a48773fSEric van Gyzen<dd>If defined, makes the additional function <code><a href= 420e3466a89SXin LI"#XML_GetAttributeInfo" >XML_GetAttributeInfo</a></code> available 421e3466a89SXin LIfor reporting attribute byte offsets.</dd> 422220ed979SColeman Kane</dl> 423220ed979SColeman Kane 4245bb6a25fSPoul-Henning Kamp<hr /> 4255bb6a25fSPoul-Henning Kamp<h2><a name="using">Using Expat</a></h2> 4265bb6a25fSPoul-Henning Kamp 4275bb6a25fSPoul-Henning Kamp<h3>Compiling and Linking Against Expat</h3> 4285bb6a25fSPoul-Henning Kamp 4295bb6a25fSPoul-Henning Kamp<p>Unless you installed Expat in a location not expected by your 4305bb6a25fSPoul-Henning Kampcompiler and linker, all you have to do to use Expat in your programs 4315bb6a25fSPoul-Henning Kampis to include the Expat header (<code>#include <expat.h></code>) 4325bb6a25fSPoul-Henning Kampin your files that make calls to it and to tell the linker that it 4335bb6a25fSPoul-Henning Kampneeds to link against the Expat library. On Unix systems, this would 4345bb6a25fSPoul-Henning Kampusually be done with the <code>-lexpat</code> argument. Otherwise, 4355bb6a25fSPoul-Henning Kampyou'll need to tell the compiler where to look for the Expat header 4365bb6a25fSPoul-Henning Kampand the linker where to find the Expat library. You may also need to 437220ed979SColeman Kanetake steps to tell the operating system where to find this library at 4385bb6a25fSPoul-Henning Kamprun time.</p> 4395bb6a25fSPoul-Henning Kamp 4405bb6a25fSPoul-Henning Kamp<p>On a Unix-based system, here's what a Makefile might look like when 4415bb6a25fSPoul-Henning KampExpat is installed in a standard location:</p> 4425bb6a25fSPoul-Henning Kamp 4435bb6a25fSPoul-Henning Kamp<pre class="eg"> 4445bb6a25fSPoul-Henning KampCC=cc 4455bb6a25fSPoul-Henning KampLDFLAGS= 4465bb6a25fSPoul-Henning KampLIBS= -lexpat 4475bb6a25fSPoul-Henning Kampxmlapp: xmlapp.o 4485bb6a25fSPoul-Henning Kamp $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS) 4495bb6a25fSPoul-Henning Kamp</pre> 4505bb6a25fSPoul-Henning Kamp 4515bb6a25fSPoul-Henning Kamp<p>If you installed Expat in, say, <code>/home/me/mystuff</code>, then 4525bb6a25fSPoul-Henning Kampthe Makefile would look like this:</p> 4535bb6a25fSPoul-Henning Kamp 4545bb6a25fSPoul-Henning Kamp<pre class="eg"> 4555bb6a25fSPoul-Henning KampCC=cc 4565bb6a25fSPoul-Henning KampCFLAGS= -I/home/me/mystuff/include 4575bb6a25fSPoul-Henning KampLDFLAGS= 4585bb6a25fSPoul-Henning KampLIBS= -L/home/me/mystuff/lib -lexpat 4595bb6a25fSPoul-Henning Kampxmlapp: xmlapp.o 4605bb6a25fSPoul-Henning Kamp $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS) 4615bb6a25fSPoul-Henning Kamp</pre> 4625bb6a25fSPoul-Henning Kamp 4635bb6a25fSPoul-Henning Kamp<p>You'd also have to set the environment variable 4645bb6a25fSPoul-Henning Kamp<code>LD_LIBRARY_PATH</code> to <code>/home/me/mystuff/lib</code> (or 4655bb6a25fSPoul-Henning Kampto <code>${LD_LIBRARY_PATH}:/home/me/mystuff/lib</code> if 4665bb6a25fSPoul-Henning KampLD_LIBRARY_PATH already has some directories in it) in order to run 4675bb6a25fSPoul-Henning Kampyour application.</p> 4685bb6a25fSPoul-Henning Kamp 4695bb6a25fSPoul-Henning Kamp<h3>Expat Basics</h3> 4705bb6a25fSPoul-Henning Kamp 4715bb6a25fSPoul-Henning Kamp<p>As we saw in the example in the overview, the first step in parsing 4725bb6a25fSPoul-Henning Kampan XML document with Expat is to create a parser object. There are <a 4735bb6a25fSPoul-Henning Kamphref="#creation">three functions</a> in the Expat API for creating a 4745bb6a25fSPoul-Henning Kampparser object. However, only two of these (<code><a href= 4755bb6a25fSPoul-Henning Kamp"#XML_ParserCreate" >XML_ParserCreate</a></code> and <code><a href= 4765bb6a25fSPoul-Henning Kamp"#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>) can be used for 4775bb6a25fSPoul-Henning Kampconstructing a parser for a top-level document. The object returned 4785bb6a25fSPoul-Henning Kampby these functions is an opaque pointer (i.e. "expat.h" declares it as 4795bb6a25fSPoul-Henning Kampvoid *) to data with further internal structure. In order to free the 4805bb6a25fSPoul-Henning Kampmemory associated with this object you must call <code><a href= 4815bb6a25fSPoul-Henning Kamp"#XML_ParserFree" >XML_ParserFree</a></code>. Note that if you have 482220ed979SColeman Kaneprovided any <a href="#userdata">user data</a> that gets stored in the 4835bb6a25fSPoul-Henning Kampparser, then your application is responsible for freeing it prior to 4845bb6a25fSPoul-Henning Kampcalling <code>XML_ParserFree</code>.</p> 4855bb6a25fSPoul-Henning Kamp 4865bb6a25fSPoul-Henning Kamp<p>The objects returned by the parser creation functions are good for 4875bb6a25fSPoul-Henning Kampparsing only one XML document or external parsed entity. If your 4885bb6a25fSPoul-Henning Kampapplication needs to parse many XML documents, then it needs to create 4895bb6a25fSPoul-Henning Kampa parser object for each one. The best way to deal with this is to 4905bb6a25fSPoul-Henning Kampcreate a higher level object that contains all the default 4915bb6a25fSPoul-Henning Kampinitialization you want for your parser objects.</p> 4925bb6a25fSPoul-Henning Kamp 4935bb6a25fSPoul-Henning Kamp<p>Walking through a document hierarchy with a stream oriented parser 4945bb6a25fSPoul-Henning Kampwill require a good stack mechanism in order to keep track of current 4955bb6a25fSPoul-Henning Kampcontext. For instance, to answer the simple question, "What element 4965bb6a25fSPoul-Henning Kampdoes this text belong to?" requires a stack, since the parser may have 4975bb6a25fSPoul-Henning Kampdescended into other elements that are children of the current one and 4985bb6a25fSPoul-Henning Kamphas encountered this text on the way out.</p> 4995bb6a25fSPoul-Henning Kamp 5005bb6a25fSPoul-Henning Kamp<p>The things you're likely to want to keep on a stack are the 5015bb6a25fSPoul-Henning Kampcurrently opened element and it's attributes. You push this 5025bb6a25fSPoul-Henning Kampinformation onto the stack in the start handler and you pop it off in 5035bb6a25fSPoul-Henning Kampthe end handler.</p> 5045bb6a25fSPoul-Henning Kamp 5055bb6a25fSPoul-Henning Kamp<p>For some tasks, it is sufficient to just keep information on what 5065bb6a25fSPoul-Henning Kampthe depth of the stack is (or would be if you had one.) The outline 5075bb6a25fSPoul-Henning Kampprogram shown above presents one example. Another such task would be 5085bb6a25fSPoul-Henning Kampskipping over a complete element. When you see the start tag for the 5095bb6a25fSPoul-Henning Kampelement you want to skip, you set a skip flag and record the depth at 5105bb6a25fSPoul-Henning Kampwhich the element started. When the end tag handler encounters the 5115bb6a25fSPoul-Henning Kampsame depth, the skipped element has ended and the flag may be 5125bb6a25fSPoul-Henning Kampcleared. If you follow the convention that the root element starts at 5135bb6a25fSPoul-Henning Kamp1, then you can use the same variable for skip flag and skip 5145bb6a25fSPoul-Henning Kampdepth.</p> 5155bb6a25fSPoul-Henning Kamp 5165bb6a25fSPoul-Henning Kamp<pre class="eg"> 5175bb6a25fSPoul-Henning Kampvoid 5185bb6a25fSPoul-Henning Kampinit_info(Parseinfo *info) { 5195bb6a25fSPoul-Henning Kamp info->skip = 0; 5205bb6a25fSPoul-Henning Kamp info->depth = 1; 5215bb6a25fSPoul-Henning Kamp /* Other initializations here */ 5225bb6a25fSPoul-Henning Kamp} /* End of init_info */ 5235bb6a25fSPoul-Henning Kamp 524220ed979SColeman Kanevoid XMLCALL 5255bb6a25fSPoul-Henning Kamprawstart(void *data, const char *el, const char **attr) { 5265bb6a25fSPoul-Henning Kamp Parseinfo *inf = (Parseinfo *) data; 5275bb6a25fSPoul-Henning Kamp 5285bb6a25fSPoul-Henning Kamp if (! inf->skip) { 5295bb6a25fSPoul-Henning Kamp if (should_skip(inf, el, attr)) { 5305bb6a25fSPoul-Henning Kamp inf->skip = inf->depth; 5315bb6a25fSPoul-Henning Kamp } 5325bb6a25fSPoul-Henning Kamp else 5335bb6a25fSPoul-Henning Kamp start(inf, el, attr); /* This does rest of start handling */ 5345bb6a25fSPoul-Henning Kamp } 5355bb6a25fSPoul-Henning Kamp 5365bb6a25fSPoul-Henning Kamp inf->depth++; 5375bb6a25fSPoul-Henning Kamp} /* End of rawstart */ 5385bb6a25fSPoul-Henning Kamp 539220ed979SColeman Kanevoid XMLCALL 5405bb6a25fSPoul-Henning Kamprawend(void *data, const char *el) { 5415bb6a25fSPoul-Henning Kamp Parseinfo *inf = (Parseinfo *) data; 5425bb6a25fSPoul-Henning Kamp 5435bb6a25fSPoul-Henning Kamp inf->depth--; 5445bb6a25fSPoul-Henning Kamp 5455bb6a25fSPoul-Henning Kamp if (! inf->skip) 5465bb6a25fSPoul-Henning Kamp end(inf, el); /* This does rest of end handling */ 5475bb6a25fSPoul-Henning Kamp 5485bb6a25fSPoul-Henning Kamp if (inf->skip == inf->depth) 5495bb6a25fSPoul-Henning Kamp inf->skip = 0; 5505bb6a25fSPoul-Henning Kamp} /* End rawend */ 5515bb6a25fSPoul-Henning Kamp</pre> 5525bb6a25fSPoul-Henning Kamp 5535bb6a25fSPoul-Henning Kamp<p>Notice in the above example the difference in how depth is 5545bb6a25fSPoul-Henning Kampmanipulated in the start and end handlers. The end tag handler should 5555bb6a25fSPoul-Henning Kampbe the mirror image of the start tag handler. This is necessary to 5565bb6a25fSPoul-Henning Kampproperly model containment. Since, in the start tag handler, we 5575bb6a25fSPoul-Henning Kampincremented depth <em>after</em> the main body of start tag code, then 5585bb6a25fSPoul-Henning Kampin the end handler, we need to manipulate it <em>before</em> the main 5595bb6a25fSPoul-Henning Kampbody. If we'd decided to increment it first thing in the start 5605bb6a25fSPoul-Henning Kamphandler, then we'd have had to decrement it last thing in the end 5615bb6a25fSPoul-Henning Kamphandler.</p> 5625bb6a25fSPoul-Henning Kamp 5635bb6a25fSPoul-Henning Kamp<h3 id="userdata">Communicating between handlers</h3> 5645bb6a25fSPoul-Henning Kamp 5655bb6a25fSPoul-Henning Kamp<p>In order to be able to pass information between different handlers 5665bb6a25fSPoul-Henning Kampwithout using globals, you'll need to define a data structure to hold 5675bb6a25fSPoul-Henning Kampthe shared variables. You can then tell Expat (with the <code><a href= 5685bb6a25fSPoul-Henning Kamp"#XML_SetUserData" >XML_SetUserData</a></code> function) to pass a 569220ed979SColeman Kanepointer to this structure to the handlers. This is the first 570220ed979SColeman Kaneargument received by most handlers. In the <a href="#reference" 571220ed979SColeman Kane>reference section</a>, an argument to a callback function is named 572220ed979SColeman Kane<code>userData</code> and have type <code>void *</code> if the user 573220ed979SColeman Kanedata is passed; it will have the type <code>XML_Parser</code> if the 574220ed979SColeman Kaneparser itself is passed. When the parser is passed, the user data may 575220ed979SColeman Kanebe retrieved using <code><a href="#XML_GetUserData" 576220ed979SColeman Kane>XML_GetUserData</a></code>.</p> 577220ed979SColeman Kane 578220ed979SColeman Kane<p>One common case where multiple calls to a single handler may need 579220ed979SColeman Kaneto communicate using an application data structure is the case when 580220ed979SColeman Kanecontent passed to the character data handler (set by <code><a href= 581220ed979SColeman Kane"#XML_SetCharacterDataHandler" 582220ed979SColeman Kane>XML_SetCharacterDataHandler</a></code>) needs to be accumulated. A 583220ed979SColeman Kanecommon first-time mistake with any of the event-oriented interfaces to 584220ed979SColeman Kanean XML parser is to expect all the text contained in an element to be 585220ed979SColeman Kanereported by a single call to the character data handler. Expat, like 586220ed979SColeman Kanemany other XML parsers, reports such data as a sequence of calls; 587220ed979SColeman Kanethere's no way to know when the end of the sequence is reached until a 588220ed979SColeman Kanedifferent callback is made. A buffer referenced by the user data 589220ed979SColeman Kanestructure proves both an effective and convenient place to accumulate 590220ed979SColeman Kanecharacter data.</p> 591220ed979SColeman Kane 592220ed979SColeman Kane<!-- XXX example needed here --> 593220ed979SColeman Kane 5945bb6a25fSPoul-Henning Kamp 5955bb6a25fSPoul-Henning Kamp<h3>XML Version</h3> 5965bb6a25fSPoul-Henning Kamp 5975bb6a25fSPoul-Henning Kamp<p>Expat is an XML 1.0 parser, and as such never complains based on 5985bb6a25fSPoul-Henning Kampthe value of the <code>version</code> pseudo-attribute in the XML 5995bb6a25fSPoul-Henning Kampdeclaration, if present.</p> 6005bb6a25fSPoul-Henning Kamp 6015bb6a25fSPoul-Henning Kamp<p>If an application needs to check the version number (to support 6025bb6a25fSPoul-Henning Kampalternate processing), it should use the <code><a href= 6035bb6a25fSPoul-Henning Kamp"#XML_SetXmlDeclHandler" >XML_SetXmlDeclHandler</a></code> function to 6045bb6a25fSPoul-Henning Kampset a handler that uses the information in the XML declaration to 6055bb6a25fSPoul-Henning Kampdetermine what to do. This example shows how to check that only a 6065bb6a25fSPoul-Henning Kampversion number of <code>"1.0"</code> is accepted:</p> 6075bb6a25fSPoul-Henning Kamp 6085bb6a25fSPoul-Henning Kamp<pre class="eg"> 6095bb6a25fSPoul-Henning Kampstatic int wrong_version; 6105bb6a25fSPoul-Henning Kampstatic XML_Parser parser; 6115bb6a25fSPoul-Henning Kamp 612220ed979SColeman Kanestatic void XMLCALL 6135bb6a25fSPoul-Henning Kampxmldecl_handler(void *userData, 6145bb6a25fSPoul-Henning Kamp const XML_Char *version, 6155bb6a25fSPoul-Henning Kamp const XML_Char *encoding, 6165bb6a25fSPoul-Henning Kamp int standalone) 6175bb6a25fSPoul-Henning Kamp{ 6185bb6a25fSPoul-Henning Kamp static const XML_Char Version_1_0[] = {'1', '.', '0', 0}; 6195bb6a25fSPoul-Henning Kamp 6205bb6a25fSPoul-Henning Kamp int i; 6215bb6a25fSPoul-Henning Kamp 6225bb6a25fSPoul-Henning Kamp for (i = 0; i < (sizeof(Version_1_0) / sizeof(Version_1_0[0])); ++i) { 6235bb6a25fSPoul-Henning Kamp if (version[i] != Version_1_0[i]) { 6245bb6a25fSPoul-Henning Kamp wrong_version = 1; 6255bb6a25fSPoul-Henning Kamp /* also clear all other handlers: */ 6265bb6a25fSPoul-Henning Kamp XML_SetCharacterDataHandler(parser, NULL); 6275bb6a25fSPoul-Henning Kamp ... 6285bb6a25fSPoul-Henning Kamp return; 6295bb6a25fSPoul-Henning Kamp } 6305bb6a25fSPoul-Henning Kamp } 6315bb6a25fSPoul-Henning Kamp ... 6325bb6a25fSPoul-Henning Kamp} 6335bb6a25fSPoul-Henning Kamp</pre> 6345bb6a25fSPoul-Henning Kamp 6355bb6a25fSPoul-Henning Kamp<h3>Namespace Processing</h3> 6365bb6a25fSPoul-Henning Kamp 6375bb6a25fSPoul-Henning Kamp<p>When the parser is created using the <code><a href= 6385bb6a25fSPoul-Henning Kamp"#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>, function, Expat 6395bb6a25fSPoul-Henning Kampperforms namespace processing. Under namespace processing, Expat 6405bb6a25fSPoul-Henning Kampconsumes <code>xmlns</code> and <code>xmlns:...</code> attributes, 6415bb6a25fSPoul-Henning Kampwhich declare namespaces for the scope of the element in which they 6425bb6a25fSPoul-Henning Kampoccur. This means that your start handler will not see these 6435bb6a25fSPoul-Henning Kampattributes. Your application can still be informed of these 6445bb6a25fSPoul-Henning Kampdeclarations by setting namespace declaration handlers with <a href= 6455bb6a25fSPoul-Henning Kamp"#XML_SetNamespaceDeclHandler" 6465bb6a25fSPoul-Henning Kamp><code>XML_SetNamespaceDeclHandler</code></a>.</p> 6475bb6a25fSPoul-Henning Kamp 6485bb6a25fSPoul-Henning Kamp<p>Element type and attribute names that belong to a given namespace 6495bb6a25fSPoul-Henning Kampare passed to the appropriate handler in expanded form. By default 6505bb6a25fSPoul-Henning Kampthis expanded form is a concatenation of the namespace URI, the 6515bb6a25fSPoul-Henning Kampseparator character (which is the 2nd argument to <code><a href= 6525bb6a25fSPoul-Henning Kamp"#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>), and the local 6535bb6a25fSPoul-Henning Kampname (i.e. the part after the colon). Names with undeclared prefixes 654220ed979SColeman Kaneare not well-formed when namespace processing is enabled, and will 655220ed979SColeman Kanetrigger an error. Unprefixed attribute names are never expanded, 6565bb6a25fSPoul-Henning Kampand unprefixed element names are only expanded when they are in the 6575bb6a25fSPoul-Henning Kampscope of a default namespace.</p> 6585bb6a25fSPoul-Henning Kamp 659220ed979SColeman Kane<p>However if <code><a href= "#XML_SetReturnNSTriplet" 6605bb6a25fSPoul-Henning Kamp>XML_SetReturnNSTriplet</a></code> has been called with a non-zero 6615bb6a25fSPoul-Henning Kamp<code>do_nst</code> parameter, then the expanded form for names with 6625bb6a25fSPoul-Henning Kampan explicit prefix is a concatenation of: URI, separator, local name, 6635bb6a25fSPoul-Henning Kampseparator, prefix.</p> 6645bb6a25fSPoul-Henning Kamp 6655bb6a25fSPoul-Henning Kamp<p>You can set handlers for the start of a namespace declaration and 6665bb6a25fSPoul-Henning Kampfor the end of a scope of a declaration with the <code><a href= 6675bb6a25fSPoul-Henning Kamp"#XML_SetNamespaceDeclHandler" >XML_SetNamespaceDeclHandler</a></code> 6685bb6a25fSPoul-Henning Kampfunction. The StartNamespaceDeclHandler is called prior to the start 669220ed979SColeman Kanetag handler and the EndNamespaceDeclHandler is called after the 6705bb6a25fSPoul-Henning Kampcorresponding end tag that ends the namespace's scope. The namespace 6715bb6a25fSPoul-Henning Kampstart handler gets passed the prefix and URI for the namespace. For a 6725bb6a25fSPoul-Henning Kampdefault namespace declaration (xmlns='...'), the prefix will be null. 6735bb6a25fSPoul-Henning KampThe URI will be null for the case where the default namespace is being 6745bb6a25fSPoul-Henning Kampunset. The namespace end handler just gets the prefix for the closing 6755bb6a25fSPoul-Henning Kampscope.</p> 6765bb6a25fSPoul-Henning Kamp 6775bb6a25fSPoul-Henning Kamp<p>These handlers are called for each declaration. So if, for 6785bb6a25fSPoul-Henning Kampinstance, a start tag had three namespace declarations, then the 6795bb6a25fSPoul-Henning KampStartNamespaceDeclHandler would be called three times before the start 6805bb6a25fSPoul-Henning Kamptag handler is called, once for each declaration.</p> 6815bb6a25fSPoul-Henning Kamp 6825bb6a25fSPoul-Henning Kamp<h3>Character Encodings</h3> 6835bb6a25fSPoul-Henning Kamp 6845bb6a25fSPoul-Henning Kamp<p>While XML is based on Unicode, and every XML processor is required 6855bb6a25fSPoul-Henning Kampto recognized UTF-8 and UTF-16 (1 and 2 byte encodings of Unicode), 6865bb6a25fSPoul-Henning Kampother encodings may be declared in XML documents or entities. For the 6875bb6a25fSPoul-Henning Kampmain document, an XML declaration may contain an encoding 6885bb6a25fSPoul-Henning Kampdeclaration:</p> 6895bb6a25fSPoul-Henning Kamp<pre> 6905bb6a25fSPoul-Henning Kamp<?xml version="1.0" encoding="ISO-8859-2"?> 6915bb6a25fSPoul-Henning Kamp</pre> 6925bb6a25fSPoul-Henning Kamp 6935bb6a25fSPoul-Henning Kamp<p>External parsed entities may begin with a text declaration, which 6945bb6a25fSPoul-Henning Kamplooks like an XML declaration with just an encoding declaration:</p> 6955bb6a25fSPoul-Henning Kamp<pre> 6965bb6a25fSPoul-Henning Kamp<?xml encoding="Big5"?> 6975bb6a25fSPoul-Henning Kamp</pre> 6985bb6a25fSPoul-Henning Kamp 6995bb6a25fSPoul-Henning Kamp<p>With Expat, you may also specify an encoding at the time of 7005bb6a25fSPoul-Henning Kampcreating a parser. This is useful when the encoding information may 7015bb6a25fSPoul-Henning Kampcome from a source outside the document itself (like a higher level 7025bb6a25fSPoul-Henning Kampprotocol.)</p> 7035bb6a25fSPoul-Henning Kamp 7045bb6a25fSPoul-Henning Kamp<p><a name="builtin_encodings"></a>There are four built-in encodings 7055bb6a25fSPoul-Henning Kampin Expat:</p> 7065bb6a25fSPoul-Henning Kamp<ul> 7075bb6a25fSPoul-Henning Kamp<li>UTF-8</li> 7085bb6a25fSPoul-Henning Kamp<li>UTF-16</li> 7095bb6a25fSPoul-Henning Kamp<li>ISO-8859-1</li> 7105bb6a25fSPoul-Henning Kamp<li>US-ASCII</li> 7115bb6a25fSPoul-Henning Kamp</ul> 7125bb6a25fSPoul-Henning Kamp 7135bb6a25fSPoul-Henning Kamp<p>Anything else discovered in an encoding declaration or in the 7145bb6a25fSPoul-Henning Kampprotocol encoding specified in the parser constructor, triggers a call 7155bb6a25fSPoul-Henning Kampto the <code>UnknownEncodingHandler</code>. This handler gets passed 7165bb6a25fSPoul-Henning Kampthe encoding name and a pointer to an <code>XML_Encoding</code> data 717220ed979SColeman Kanestructure. Your handler must fill in this structure and return 718220ed979SColeman Kane<code>XML_STATUS_OK</code> if it knows how to deal with the 719220ed979SColeman Kaneencoding. Otherwise the handler should return 720220ed979SColeman Kane<code>XML_STATUS_ERROR</code>. The handler also gets passed a pointer 721220ed979SColeman Kaneto an optional application data structure that you may indicate when 722220ed979SColeman Kaneyou set the handler.</p> 7235bb6a25fSPoul-Henning Kamp 7245bb6a25fSPoul-Henning Kamp<p>Expat places restrictions on character encodings that it can 7255bb6a25fSPoul-Henning Kampsupport by filling in the <code>XML_Encoding</code> structure. 7265bb6a25fSPoul-Henning Kampinclude file:</p> 7275bb6a25fSPoul-Henning Kamp<ol> 7285bb6a25fSPoul-Henning Kamp<li>Every ASCII character that can appear in a well-formed XML document 7295bb6a25fSPoul-Henning Kampmust be represented by a single byte, and that byte must correspond to 7305bb6a25fSPoul-Henning Kampit's ASCII encoding (except for the characters $@\^'{}~)</li> 7315bb6a25fSPoul-Henning Kamp<li>Characters must be encoded in 4 bytes or less.</li> 7325bb6a25fSPoul-Henning Kamp<li>All characters encoded must have Unicode scalar values less than or 7335bb6a25fSPoul-Henning Kampequal to 65535 (0xFFFF)<em>This does not apply to the built-in support 7345bb6a25fSPoul-Henning Kampfor UTF-16 and UTF-8</em></li> 7355bb6a25fSPoul-Henning Kamp<li>No character may be encoded by more that one distinct sequence of 7365bb6a25fSPoul-Henning Kampbytes</li> 7375bb6a25fSPoul-Henning Kamp</ol> 7385bb6a25fSPoul-Henning Kamp 7395bb6a25fSPoul-Henning Kamp<p><code>XML_Encoding</code> contains an array of integers that 7405bb6a25fSPoul-Henning Kampcorrespond to the 1st byte of an encoding sequence. If the value in 7415bb6a25fSPoul-Henning Kampthe array for a byte is zero or positive, then the byte is a single 7425bb6a25fSPoul-Henning Kampbyte encoding that encodes the Unicode scalar value contained in the 7435bb6a25fSPoul-Henning Kamparray. A -1 in this array indicates a malformed byte. If the value is 7445bb6a25fSPoul-Henning Kamp-2, -3, or -4, then the byte is the beginning of a 2, 3, or 4 byte 7455bb6a25fSPoul-Henning Kampsequence respectively. Multi-byte sequences are sent to the convert 7465bb6a25fSPoul-Henning Kampfunction pointed at in the <code>XML_Encoding</code> structure. This 7475bb6a25fSPoul-Henning Kampfunction should return the Unicode scalar value for the sequence or -1 7485bb6a25fSPoul-Henning Kampif the sequence is malformed.</p> 7495bb6a25fSPoul-Henning Kamp 7505bb6a25fSPoul-Henning Kamp<p>One pitfall that novice Expat users are likely to fall into is that 7515bb6a25fSPoul-Henning Kampalthough Expat may accept input in various encodings, the strings that 7525bb6a25fSPoul-Henning Kampit passes to the handlers are always encoded in UTF-8 or UTF-16 7535bb6a25fSPoul-Henning Kamp(depending on how Expat was compiled). Your application is responsible 7545bb6a25fSPoul-Henning Kampfor any translation of these strings into other encodings.</p> 7555bb6a25fSPoul-Henning Kamp 7565bb6a25fSPoul-Henning Kamp<h3>Handling External Entity References</h3> 7575bb6a25fSPoul-Henning Kamp 7585bb6a25fSPoul-Henning Kamp<p>Expat does not read or parse external entities directly. Note that 7595bb6a25fSPoul-Henning Kampany external DTD is a special case of an external entity. If you've 7605bb6a25fSPoul-Henning Kampset no <code>ExternalEntityRefHandler</code>, then external entity 7615bb6a25fSPoul-Henning Kampreferences are silently ignored. Otherwise, it calls your handler with 7625bb6a25fSPoul-Henning Kampthe information needed to read and parse the external entity.</p> 7635bb6a25fSPoul-Henning Kamp 7645bb6a25fSPoul-Henning Kamp<p>Your handler isn't actually responsible for parsing the entity, but 7655bb6a25fSPoul-Henning Kampit is responsible for creating a subsidiary parser with <code><a href= 7665bb6a25fSPoul-Henning Kamp"#XML_ExternalEntityParserCreate" 7675bb6a25fSPoul-Henning Kamp>XML_ExternalEntityParserCreate</a></code> that will do the job. This 7685bb6a25fSPoul-Henning Kampreturns an instance of <code>XML_Parser</code> that has handlers and 7695bb6a25fSPoul-Henning Kampother data structures initialized from the parent parser. You may then 7705bb6a25fSPoul-Henning Kampuse <code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a 7715bb6a25fSPoul-Henning Kamphref= "#XML_ParseBuffer">XML_ParseBuffer</a></code> calls against this 7725bb6a25fSPoul-Henning Kampparser. Since external entities my refer to other external entities, 7735bb6a25fSPoul-Henning Kampyour handler should be prepared to be called recursively.</p> 7745bb6a25fSPoul-Henning Kamp 7755bb6a25fSPoul-Henning Kamp<h3>Parsing DTDs</h3> 7765bb6a25fSPoul-Henning Kamp 7775bb6a25fSPoul-Henning Kamp<p>In order to parse parameter entities, before starting the parse, 7785bb6a25fSPoul-Henning Kampyou must call <code><a href= "#XML_SetParamEntityParsing" 7795bb6a25fSPoul-Henning Kamp>XML_SetParamEntityParsing</a></code> with one of the following 7805bb6a25fSPoul-Henning Kamparguments:</p> 7815bb6a25fSPoul-Henning Kamp<dl> 7825bb6a25fSPoul-Henning Kamp<dt><code>XML_PARAM_ENTITY_PARSING_NEVER</code></dt> 7835bb6a25fSPoul-Henning Kamp<dd>Don't parse parameter entities or the external subset</dd> 7845bb6a25fSPoul-Henning Kamp<dt><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></dt> 7850a48773fSEric van Gyzen<dd>Parse parameter entities and the external subset unless 7865bb6a25fSPoul-Henning Kamp<code>standalone</code> was set to "yes" in the XML declaration.</dd> 7875bb6a25fSPoul-Henning Kamp<dt><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></dt> 7885bb6a25fSPoul-Henning Kamp<dd>Always parse parameter entities and the external subset</dd> 7895bb6a25fSPoul-Henning Kamp</dl> 7905bb6a25fSPoul-Henning Kamp 7915bb6a25fSPoul-Henning Kamp<p>In order to read an external DTD, you also have to set an external 7925bb6a25fSPoul-Henning Kampentity reference handler as described above.</p> 7935bb6a25fSPoul-Henning Kamp 794220ed979SColeman Kane<h3 id="stop-resume">Temporarily Stopping Parsing</h3> 795220ed979SColeman Kane 796220ed979SColeman Kane<p>Expat 1.95.8 introduces a new feature: its now possible to stop 797220ed979SColeman Kaneparsing temporarily from within a handler function, even if more data 798220ed979SColeman Kanehas already been passed into the parser. Applications for this 799220ed979SColeman Kaneinclude</p> 800220ed979SColeman Kane 801220ed979SColeman Kane<ul> 802220ed979SColeman Kane <li>Supporting the <a href= "http://www.w3.org/TR/xinclude/" 803220ed979SColeman Kane >XInclude</a> specification.</li> 804220ed979SColeman Kane 805220ed979SColeman Kane <li>Delaying further processing until additional information is 806220ed979SColeman Kane available from some other source.</li> 807220ed979SColeman Kane 808220ed979SColeman Kane <li>Adjusting processor load as task priorities shift within an 809220ed979SColeman Kane application.</li> 810220ed979SColeman Kane 811220ed979SColeman Kane <li>Stopping parsing completely (simply free or reset the parser 812220ed979SColeman Kane instead of resuming in the outer parsing loop). This can be useful 8130a48773fSEric van Gyzen if an application-domain error is found in the XML being parsed or if 814220ed979SColeman Kane the result of the parse is determined not to be useful after 815220ed979SColeman Kane all.</li> 816220ed979SColeman Kane</ul> 817220ed979SColeman Kane 818220ed979SColeman Kane<p>To take advantage of this feature, the main parsing loop of an 819220ed979SColeman Kaneapplication needs to support this specifically. It cannot be 820220ed979SColeman Kanesupported with a parsing loop compatible with Expat 1.95.7 or 821220ed979SColeman Kaneearlier (though existing loops will continue to work without 822220ed979SColeman Kanesupporting the stop/resume feature).</p> 823220ed979SColeman Kane 824220ed979SColeman Kane<p>An application that uses this feature for a single parser will have 825220ed979SColeman Kanethe rough structure (in pseudo-code):</p> 826220ed979SColeman Kane 827220ed979SColeman Kane<pre class="pseudocode"> 828220ed979SColeman Kanefd = open_input() 829220ed979SColeman Kanep = create_parser() 830220ed979SColeman Kane 831220ed979SColeman Kaneif parse_xml(p, fd) { 832220ed979SColeman Kane /* suspended */ 833220ed979SColeman Kane 834220ed979SColeman Kane int suspended = 1; 835220ed979SColeman Kane 836220ed979SColeman Kane while (suspended) { 837220ed979SColeman Kane do_something_else() 838220ed979SColeman Kane if ready_to_resume() { 839220ed979SColeman Kane suspended = continue_parsing(p, fd); 840220ed979SColeman Kane } 841220ed979SColeman Kane } 842220ed979SColeman Kane} 843220ed979SColeman Kane</pre> 844220ed979SColeman Kane 845220ed979SColeman Kane<p>An application that may resume any of several parsers based on 846220ed979SColeman Kaneinput (either from the XML being parsed or some other source) will 847220ed979SColeman Kanecertainly have more interesting control structures.</p> 848220ed979SColeman Kane 849220ed979SColeman Kane<p>This C function could be used for the <code>parse_xml</code> 850220ed979SColeman Kanefunction mentioned in the pseudo-code above:</p> 851220ed979SColeman Kane 852220ed979SColeman Kane<pre class="eg"> 853220ed979SColeman Kane#define BUFF_SIZE 10240 854220ed979SColeman Kane 855220ed979SColeman Kane/* Parse a document from the open file descriptor 'fd' until the parse 856220ed979SColeman Kane is complete (the document has been completely parsed, or there's 857220ed979SColeman Kane been an error), or the parse is stopped. Return non-zero when 858220ed979SColeman Kane the parse is merely suspended. 859220ed979SColeman Kane*/ 860220ed979SColeman Kaneint 861220ed979SColeman Kaneparse_xml(XML_Parser p, int fd) 862220ed979SColeman Kane{ 863220ed979SColeman Kane for (;;) { 864220ed979SColeman Kane int last_chunk; 865220ed979SColeman Kane int bytes_read; 866220ed979SColeman Kane enum XML_Status status; 867220ed979SColeman Kane 868220ed979SColeman Kane void *buff = XML_GetBuffer(p, BUFF_SIZE); 869220ed979SColeman Kane if (buff == NULL) { 870220ed979SColeman Kane /* handle error... */ 871220ed979SColeman Kane return 0; 872220ed979SColeman Kane } 873220ed979SColeman Kane bytes_read = read(fd, buff, BUFF_SIZE); 874220ed979SColeman Kane if (bytes_read < 0) { 875220ed979SColeman Kane /* handle error... */ 876220ed979SColeman Kane return 0; 877220ed979SColeman Kane } 878220ed979SColeman Kane status = XML_ParseBuffer(p, bytes_read, bytes_read == 0); 879220ed979SColeman Kane switch (status) { 880220ed979SColeman Kane case XML_STATUS_ERROR: 881220ed979SColeman Kane /* handle error... */ 882220ed979SColeman Kane return 0; 883220ed979SColeman Kane case XML_STATUS_SUSPENDED: 884220ed979SColeman Kane return 1; 885220ed979SColeman Kane } 886220ed979SColeman Kane if (bytes_read == 0) 887220ed979SColeman Kane return 0; 888220ed979SColeman Kane } 889220ed979SColeman Kane} 890220ed979SColeman Kane</pre> 891220ed979SColeman Kane 892220ed979SColeman Kane<p>The corresponding <code>continue_parsing</code> function is 893220ed979SColeman Kanesomewhat simpler, since it only need deal with the return code from 894220ed979SColeman Kane<code><a href= "#XML_ResumeParser">XML_ResumeParser</a></code>; it can 895220ed979SColeman Kanedelegate the input handling to the <code>parse_xml</code> 896220ed979SColeman Kanefunction:</p> 897220ed979SColeman Kane 898220ed979SColeman Kane<pre class="eg"> 899220ed979SColeman Kane/* Continue parsing a document which had been suspended. The 'p' and 900220ed979SColeman Kane 'fd' arguments are the same as passed to parse_xml(). Return 901220ed979SColeman Kane non-zero when the parse is suspended. 902220ed979SColeman Kane*/ 903220ed979SColeman Kaneint 904220ed979SColeman Kanecontinue_parsing(XML_Parser p, int fd) 905220ed979SColeman Kane{ 906220ed979SColeman Kane enum XML_Status status = XML_ResumeParser(p); 907220ed979SColeman Kane switch (status) { 908220ed979SColeman Kane case XML_STATUS_ERROR: 909220ed979SColeman Kane /* handle error... */ 910220ed979SColeman Kane return 0; 911220ed979SColeman Kane case XML_ERROR_NOT_SUSPENDED: 912220ed979SColeman Kane /* handle error... */ 913220ed979SColeman Kane return 0;. 914220ed979SColeman Kane case XML_STATUS_SUSPENDED: 915220ed979SColeman Kane return 1; 916220ed979SColeman Kane } 917220ed979SColeman Kane return parse_xml(p, fd); 918220ed979SColeman Kane} 919220ed979SColeman Kane</pre> 920220ed979SColeman Kane 921220ed979SColeman Kane<p>Now that we've seen what a mess the top-level parsing loop can 922220ed979SColeman Kanebecome, what have we gained? Very simply, we can now use the <code><a 923220ed979SColeman Kanehref= "#XML_StopParser" >XML_StopParser</a></code> function to stop 924220ed979SColeman Kaneparsing, without having to go to great lengths to avoid additional 925220ed979SColeman Kaneprocessing that we're expecting to ignore. As a bonus, we get to stop 926220ed979SColeman Kaneparsing <em>temporarily</em>, and come back to it when we're 927220ed979SColeman Kaneready.</p> 928220ed979SColeman Kane 929220ed979SColeman Kane<p>To stop parsing from a handler function, use the <code><a href= 930220ed979SColeman Kane"#XML_StopParser" >XML_StopParser</a></code> function. This function 931220ed979SColeman Kanetakes two arguments; the parser being stopped and a flag indicating 932220ed979SColeman Kanewhether the parse can be resumed in the future.</p> 933220ed979SColeman Kane 934220ed979SColeman Kane<!-- XXX really need more here --> 935220ed979SColeman Kane 936220ed979SColeman Kane 9375bb6a25fSPoul-Henning Kamp<hr /> 9385bb6a25fSPoul-Henning Kamp<!-- ================================================================ --> 9395bb6a25fSPoul-Henning Kamp 9405bb6a25fSPoul-Henning Kamp<h2><a name="reference">Expat Reference</a></h2> 9415bb6a25fSPoul-Henning Kamp 9425bb6a25fSPoul-Henning Kamp<h3><a name="creation">Parser Creation</a></h3> 9435bb6a25fSPoul-Henning Kamp 944cc68614dSXin LI<h4 id="XML_ParserCreate">XML_ParserCreate</h4> 945cc68614dSXin LI<pre class="fcndec"> 946220ed979SColeman KaneXML_Parser XMLCALL 9475bb6a25fSPoul-Henning KampXML_ParserCreate(const XML_Char *encoding); 9485bb6a25fSPoul-Henning Kamp</pre> 9495bb6a25fSPoul-Henning Kamp<div class="fcndef"> 9505bb6a25fSPoul-Henning KampConstruct a new parser. If encoding is non-null, it specifies a 9515bb6a25fSPoul-Henning Kampcharacter encoding to use for the document. This overrides the document 9525bb6a25fSPoul-Henning Kampencoding declaration. There are four built-in encodings: 9535bb6a25fSPoul-Henning Kamp<ul> 9545bb6a25fSPoul-Henning Kamp<li>US-ASCII</li> 9555bb6a25fSPoul-Henning Kamp<li>UTF-8</li> 9565bb6a25fSPoul-Henning Kamp<li>UTF-16</li> 9575bb6a25fSPoul-Henning Kamp<li>ISO-8859-1</li> 9585bb6a25fSPoul-Henning Kamp</ul> 9595bb6a25fSPoul-Henning KampAny other value will invoke a call to the UnknownEncodingHandler. 9605bb6a25fSPoul-Henning Kamp</div> 9615bb6a25fSPoul-Henning Kamp 962cc68614dSXin LI<h4 id="XML_ParserCreateNS">XML_ParserCreateNS</h4> 963cc68614dSXin LI<pre class="fcndec"> 964220ed979SColeman KaneXML_Parser XMLCALL 9655bb6a25fSPoul-Henning KampXML_ParserCreateNS(const XML_Char *encoding, 9665bb6a25fSPoul-Henning Kamp XML_Char sep); 9675bb6a25fSPoul-Henning Kamp</pre> 9685bb6a25fSPoul-Henning Kamp<div class="fcndef"> 9695bb6a25fSPoul-Henning KampConstructs a new parser that has namespace processing in effect. Namespace 9705bb6a25fSPoul-Henning Kampexpanded element names and attribute names are returned as a concatenation 9715bb6a25fSPoul-Henning Kampof the namespace URI, <em>sep</em>, and the local part of the name. This 972e3466a89SXin LImeans that you should pick a character for <em>sep</em> that can't be part 973e3466a89SXin LIof an URI. Since Expat does not check namespace URIs for conformance, the 974e3466a89SXin LIonly safe choice for a namespace separator is a character that is illegal 975e3466a89SXin LIin XML. For instance, <code>'\xFF'</code> is not legal in UTF-8, and 976e3466a89SXin LI<code>'\xFFFF'</code> is not legal in UTF-16. There is a special case when 977e3466a89SXin LI<em>sep</em> is the null character <code>'\0'</code>: the namespace URI and 978e3466a89SXin LIthe local part will be concatenated without any separator - this is intended 979e3466a89SXin LIto support RDF processors. It is a programming error to use the null separator 980e3466a89SXin LIwith <a href= "#XML_SetReturnNSTriplet">namespace triplets</a>.</div> 9815bb6a25fSPoul-Henning Kamp 9827ed8e142SXin LI<p><strong>Note:</strong> 9837ed8e142SXin LIExpat does not validate namespace URIs (beyond encoding) 9847ed8e142SXin LIagainst RFC 3986 today (and is not required to do so with regard to 9857ed8e142SXin LIthe XML 1.0 namespaces specification) but it may start doing that 9867ed8e142SXin LIin future releases. Before that, an application using Expat must 9877ed8e142SXin LIbe ready to receive namespace URIs containing non-URI characters. 9887ed8e142SXin LI</p> 9897ed8e142SXin LI 990cc68614dSXin LI<h4 id="XML_ParserCreate_MM">XML_ParserCreate_MM</h4> 991cc68614dSXin LI<pre class="fcndec"> 992220ed979SColeman KaneXML_Parser XMLCALL 9935bb6a25fSPoul-Henning KampXML_ParserCreate_MM(const XML_Char *encoding, 9945bb6a25fSPoul-Henning Kamp const XML_Memory_Handling_Suite *ms, 9955bb6a25fSPoul-Henning Kamp const XML_Char *sep); 9965bb6a25fSPoul-Henning Kamp</pre> 9975bb6a25fSPoul-Henning Kamp<pre class="signature"> 9985bb6a25fSPoul-Henning Kamptypedef struct { 999220ed979SColeman Kane void *(XMLCALL *malloc_fcn)(size_t size); 1000220ed979SColeman Kane void *(XMLCALL *realloc_fcn)(void *ptr, size_t size); 1001220ed979SColeman Kane void (XMLCALL *free_fcn)(void *ptr); 10025bb6a25fSPoul-Henning Kamp} XML_Memory_Handling_Suite; 10035bb6a25fSPoul-Henning Kamp</pre> 10045bb6a25fSPoul-Henning Kamp<div class="fcndef"> 10055bb6a25fSPoul-Henning Kamp<p>Construct a new parser using the suite of memory handling functions 10065bb6a25fSPoul-Henning Kampspecified in <code>ms</code>. If <code>ms</code> is NULL, then use the 10075bb6a25fSPoul-Henning Kampstandard set of memory management functions. If <code>sep</code> is 10085bb6a25fSPoul-Henning Kampnon NULL, then namespace processing is enabled in the created parser 10095bb6a25fSPoul-Henning Kampand the character pointed at by sep is used as the separator between 10105bb6a25fSPoul-Henning Kampthe namespace URI and the local part of the name.</p> 10115bb6a25fSPoul-Henning Kamp</div> 10125bb6a25fSPoul-Henning Kamp 1013cc68614dSXin LI<h4 id="XML_ExternalEntityParserCreate">XML_ExternalEntityParserCreate</h4> 1014cc68614dSXin LI<pre class="fcndec"> 1015220ed979SColeman KaneXML_Parser XMLCALL 10165bb6a25fSPoul-Henning KampXML_ExternalEntityParserCreate(XML_Parser p, 10175bb6a25fSPoul-Henning Kamp const XML_Char *context, 10185bb6a25fSPoul-Henning Kamp const XML_Char *encoding); 10195bb6a25fSPoul-Henning Kamp</pre> 10205bb6a25fSPoul-Henning Kamp<div class="fcndef"> 10215bb6a25fSPoul-Henning KampConstruct a new <code>XML_Parser</code> object for parsing an external 10225bb6a25fSPoul-Henning Kampgeneral entity. Context is the context argument passed in a call to a 10235bb6a25fSPoul-Henning KampExternalEntityRefHandler. Other state information such as handlers, 10245bb6a25fSPoul-Henning Kampuser data, namespace processing is inherited from the parser passed as 10255bb6a25fSPoul-Henning Kampthe 1st argument. So you shouldn't need to call any of the behavior 10265bb6a25fSPoul-Henning Kampchanging functions on this parser (unless you want it to act 10275bb6a25fSPoul-Henning Kampdifferently than the parent parser). 10285bb6a25fSPoul-Henning Kamp</div> 10295bb6a25fSPoul-Henning Kamp 1030cc68614dSXin LI<h4 id="XML_ParserFree">XML_ParserFree</h4> 1031cc68614dSXin LI<pre class="fcndec"> 1032220ed979SColeman Kanevoid XMLCALL 10335bb6a25fSPoul-Henning KampXML_ParserFree(XML_Parser p); 10345bb6a25fSPoul-Henning Kamp</pre> 10355bb6a25fSPoul-Henning Kamp<div class="fcndef"> 10365bb6a25fSPoul-Henning KampFree memory used by the parser. Your application is responsible for 10375bb6a25fSPoul-Henning Kampfreeing any memory associated with <a href="#userdata">user data</a>. 10385bb6a25fSPoul-Henning Kamp</div> 10395bb6a25fSPoul-Henning Kamp 1040cc68614dSXin LI<h4 id="XML_ParserReset">XML_ParserReset</h4> 1041cc68614dSXin LI<pre class="fcndec"> 1042220ed979SColeman KaneXML_Bool XMLCALL 1043220ed979SColeman KaneXML_ParserReset(XML_Parser p, 1044220ed979SColeman Kane const XML_Char *encoding); 10455bb6a25fSPoul-Henning Kamp</pre> 10465bb6a25fSPoul-Henning Kamp<div class="fcndef"> 10475bb6a25fSPoul-Henning KampClean up the memory structures maintained by the parser so that it may 10485bb6a25fSPoul-Henning Kampbe used again. After this has been called, <code>parser</code> is 1049220ed979SColeman Kaneready to start parsing a new document. All handlers are cleared from 1050220ed979SColeman Kanethe parser, except for the unknownEncodingHandler. The parser's external 1051220ed979SColeman Kanestate is re-initialized except for the values of ns and ns_triplets. 1052220ed979SColeman KaneThis function may not be used on a parser created using <code><a href= 10535bb6a25fSPoul-Henning Kamp"#XML_ExternalEntityParserCreate" >XML_ExternalEntityParserCreate</a 10545bb6a25fSPoul-Henning Kamp></code>; it will return <code>XML_FALSE</code> in that case. Returns 10555bb6a25fSPoul-Henning Kamp<code>XML_TRUE</code> on success. Your application is responsible for 10565bb6a25fSPoul-Henning Kampdealing with any memory associated with <a href="#userdata">user data</a>. 10575bb6a25fSPoul-Henning Kamp</div> 10585bb6a25fSPoul-Henning Kamp 10595bb6a25fSPoul-Henning Kamp<h3><a name="parsing">Parsing</a></h3> 10605bb6a25fSPoul-Henning Kamp 10615bb6a25fSPoul-Henning Kamp<p>To state the obvious: the three parsing functions <code><a href= 1062220ed979SColeman Kane"#XML_Parse" >XML_Parse</a></code>, <code><a href= "#XML_ParseBuffer"> 1063220ed979SColeman KaneXML_ParseBuffer</a></code> and <code><a href= "#XML_GetBuffer"> 1064220ed979SColeman KaneXML_GetBuffer</a></code> must not be called from within a handler 1065220ed979SColeman Kaneunless they operate on a separate parser instance, that is, one that 1066220ed979SColeman Kanedid not call the handler. For example, it is OK to call the parsing 1067220ed979SColeman Kanefunctions from within an <code>XML_ExternalEntityRefHandler</code>, 1068220ed979SColeman Kaneif they apply to the parser created by 1069220ed979SColeman Kane<code><a href= "#XML_ExternalEntityParserCreate" 10705bb6a25fSPoul-Henning Kamp>XML_ExternalEntityParserCreate</a></code>.</p> 10715bb6a25fSPoul-Henning Kamp 1072cc68614dSXin LI<p>Note: The <code>len</code> argument passed to these functions 1073220ed979SColeman Kaneshould be considerably less than the maximum value for an integer, 1074220ed979SColeman Kaneas it could create an integer overflow situation if the added 1075220ed979SColeman Kanelengths of a buffer and the unprocessed portion of the previous buffer 1076220ed979SColeman Kaneexceed the maximum integer value. Input data at the end of a buffer 1077220ed979SColeman Kanewill remain unprocessed if it is part of an XML token for which the 1078220ed979SColeman Kaneend is not part of that buffer.</p> 1079220ed979SColeman Kane 1080cc68614dSXin LI<h4 id="XML_Parse">XML_Parse</h4> 1081cc68614dSXin LI<pre class="fcndec"> 1082220ed979SColeman Kaneenum XML_Status XMLCALL 10835bb6a25fSPoul-Henning KampXML_Parse(XML_Parser p, 10845bb6a25fSPoul-Henning Kamp const char *s, 10855bb6a25fSPoul-Henning Kamp int len, 10865bb6a25fSPoul-Henning Kamp int isFinal); 10875bb6a25fSPoul-Henning Kamp</pre> 10885bb6a25fSPoul-Henning Kamp<pre class="signature"> 10895bb6a25fSPoul-Henning Kampenum XML_Status { 10905bb6a25fSPoul-Henning Kamp XML_STATUS_ERROR = 0, 10915bb6a25fSPoul-Henning Kamp XML_STATUS_OK = 1 10925bb6a25fSPoul-Henning Kamp}; 10935bb6a25fSPoul-Henning Kamp</pre> 10945bb6a25fSPoul-Henning Kamp<div class="fcndef"> 10955bb6a25fSPoul-Henning KampParse some more of the document. The string <code>s</code> is a buffer 10965bb6a25fSPoul-Henning Kampcontaining part (or perhaps all) of the document. The number of bytes of s 10975bb6a25fSPoul-Henning Kampthat are part of the document is indicated by <code>len</code>. This means 10985bb6a25fSPoul-Henning Kampthat <code>s</code> doesn't have to be null terminated. It also means that 10995bb6a25fSPoul-Henning Kampif <code>len</code> is larger than the number of bytes in the block of 11005bb6a25fSPoul-Henning Kampmemory that <code>s</code> points at, then a memory fault is likely. The 11015bb6a25fSPoul-Henning Kamp<code>isFinal</code> parameter informs the parser that this is the last 11025bb6a25fSPoul-Henning Kamppiece of the document. Frequently, the last piece is empty (i.e. 11035bb6a25fSPoul-Henning Kamp<code>len</code> is zero.) 11045bb6a25fSPoul-Henning KampIf a parse error occurred, it returns <code>XML_STATUS_ERROR</code>. 11055bb6a25fSPoul-Henning KampOtherwise it returns <code>XML_STATUS_OK</code> value. 11065bb6a25fSPoul-Henning Kamp</div> 11075bb6a25fSPoul-Henning Kamp 1108cc68614dSXin LI<h4 id="XML_ParseBuffer">XML_ParseBuffer</h4> 1109cc68614dSXin LI<pre class="fcndec"> 1110220ed979SColeman Kaneenum XML_Status XMLCALL 11115bb6a25fSPoul-Henning KampXML_ParseBuffer(XML_Parser p, 11125bb6a25fSPoul-Henning Kamp int len, 11135bb6a25fSPoul-Henning Kamp int isFinal); 11145bb6a25fSPoul-Henning Kamp</pre> 11155bb6a25fSPoul-Henning Kamp<div class="fcndef"> 11165bb6a25fSPoul-Henning KampThis is just like <code><a href= "#XML_Parse" >XML_Parse</a></code>, 11175bb6a25fSPoul-Henning Kampexcept in this case Expat provides the buffer. By obtaining the 11185bb6a25fSPoul-Henning Kampbuffer from Expat with the <code><a href= "#XML_GetBuffer" 11195bb6a25fSPoul-Henning Kamp>XML_GetBuffer</a></code> function, the application can avoid double 11205bb6a25fSPoul-Henning Kampcopying of the input. 11215bb6a25fSPoul-Henning Kamp</div> 11225bb6a25fSPoul-Henning Kamp 1123cc68614dSXin LI<h4 id="XML_GetBuffer">XML_GetBuffer</h4> 1124cc68614dSXin LI<pre class="fcndec"> 1125220ed979SColeman Kanevoid * XMLCALL 11265bb6a25fSPoul-Henning KampXML_GetBuffer(XML_Parser p, 11275bb6a25fSPoul-Henning Kamp int len); 11285bb6a25fSPoul-Henning Kamp</pre> 11295bb6a25fSPoul-Henning Kamp<div class="fcndef"> 11305bb6a25fSPoul-Henning KampObtain a buffer of size <code>len</code> to read a piece of the document 11315bb6a25fSPoul-Henning Kampinto. A NULL value is returned if Expat can't allocate enough memory for 1132cc68614dSXin LIthis buffer. A NULL value may also be returned if <code>len</code> is zero. 1133cc68614dSXin LIThis has to be called prior to every call to 11345bb6a25fSPoul-Henning Kamp<code><a href= "#XML_ParseBuffer" >XML_ParseBuffer</a></code>. A 11355bb6a25fSPoul-Henning Kamptypical use would look like this: 11365bb6a25fSPoul-Henning Kamp 11375bb6a25fSPoul-Henning Kamp<pre class="eg"> 11385bb6a25fSPoul-Henning Kampfor (;;) { 11395bb6a25fSPoul-Henning Kamp int bytes_read; 11405bb6a25fSPoul-Henning Kamp void *buff = XML_GetBuffer(p, BUFF_SIZE); 11415bb6a25fSPoul-Henning Kamp if (buff == NULL) { 11425bb6a25fSPoul-Henning Kamp /* handle error */ 11435bb6a25fSPoul-Henning Kamp } 11445bb6a25fSPoul-Henning Kamp 11455bb6a25fSPoul-Henning Kamp bytes_read = read(docfd, buff, BUFF_SIZE); 11465bb6a25fSPoul-Henning Kamp if (bytes_read < 0) { 11475bb6a25fSPoul-Henning Kamp /* handle error */ 11485bb6a25fSPoul-Henning Kamp } 11495bb6a25fSPoul-Henning Kamp 11505bb6a25fSPoul-Henning Kamp if (! XML_ParseBuffer(p, bytes_read, bytes_read == 0)) { 11515bb6a25fSPoul-Henning Kamp /* handle parse error */ 11525bb6a25fSPoul-Henning Kamp } 11535bb6a25fSPoul-Henning Kamp 11545bb6a25fSPoul-Henning Kamp if (bytes_read == 0) 11555bb6a25fSPoul-Henning Kamp break; 11565bb6a25fSPoul-Henning Kamp} 11575bb6a25fSPoul-Henning Kamp</pre> 11585bb6a25fSPoul-Henning Kamp</div> 11595bb6a25fSPoul-Henning Kamp 1160cc68614dSXin LI<h4 id="XML_StopParser">XML_StopParser</h4> 1161cc68614dSXin LI<pre class="fcndec"> 1162220ed979SColeman Kaneenum XML_Status XMLCALL 1163220ed979SColeman KaneXML_StopParser(XML_Parser p, 1164220ed979SColeman Kane XML_Bool resumable); 1165220ed979SColeman Kane</pre> 1166220ed979SColeman Kane<div class="fcndef"> 1167220ed979SColeman Kane 1168220ed979SColeman Kane<p>Stops parsing, causing <code><a href= "#XML_Parse" 1169220ed979SColeman Kane>XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer" 1170220ed979SColeman Kane>XML_ParseBuffer</a></code> to return. Must be called from within a 1171220ed979SColeman Kanecall-back handler, except when aborting (when <code>resumable</code> 1172220ed979SColeman Kaneis <code>XML_FALSE</code>) an already suspended parser. Some 1173220ed979SColeman Kanecall-backs may still follow because they would otherwise get 1174cc68614dSXin LIlost, including</p> 1175220ed979SColeman Kane<ul> 1176220ed979SColeman Kane <li> the end element handler for empty elements when stopped in the 1177220ed979SColeman Kane start element handler,</li> 1178220ed979SColeman Kane <li> the end namespace declaration handler when stopped in the end 1179220ed979SColeman Kane element handler,</li> 1180220ed979SColeman Kane <li> the character data handler when stopped in the character data handler 1181220ed979SColeman Kane while making multiple call-backs on a contiguous chunk of characters,</li> 1182220ed979SColeman Kane</ul> 1183cc68614dSXin LI<p>and possibly others.</p> 1184220ed979SColeman Kane 1185220ed979SColeman Kane<p>This can be called from most handlers, including DTD related 1186220ed979SColeman Kanecall-backs, except when parsing an external parameter entity and 1187220ed979SColeman Kane<code>resumable</code> is <code>XML_TRUE</code>. Returns 1188220ed979SColeman Kane<code>XML_STATUS_OK</code> when successful, 1189220ed979SColeman Kane<code>XML_STATUS_ERROR</code> otherwise. The possible error codes 1190220ed979SColeman Kaneare:</p> 1191220ed979SColeman Kane<dl> 1192220ed979SColeman Kane <dt><code>XML_ERROR_SUSPENDED</code></dt> 1193220ed979SColeman Kane <dd>when suspending an already suspended parser.</dd> 1194220ed979SColeman Kane <dt><code>XML_ERROR_FINISHED</code></dt> 1195220ed979SColeman Kane <dd>when the parser has already finished.</dd> 1196220ed979SColeman Kane <dt><code>XML_ERROR_SUSPEND_PE</code></dt> 1197220ed979SColeman Kane <dd>when suspending while parsing an external PE.</dd> 1198220ed979SColeman Kane</dl> 1199220ed979SColeman Kane 1200220ed979SColeman Kane<p>Since the stop/resume feature requires application support in the 1201220ed979SColeman Kaneouter parsing loop, it is an error to call this function for a parser 1202220ed979SColeman Kanenot being handled appropriately; see <a href= "#stop-resume" 1203220ed979SColeman Kane>Temporarily Stopping Parsing</a> for more information.</p> 1204220ed979SColeman Kane 1205220ed979SColeman Kane<p>When <code>resumable</code> is <code>XML_TRUE</code> then parsing 1206220ed979SColeman Kaneis <em>suspended</em>, that is, <code><a href= "#XML_Parse" 1207220ed979SColeman Kane>XML_Parse</a></code> and <code><a href= "#XML_ParseBuffer" 1208220ed979SColeman Kane>XML_ParseBuffer</a></code> return <code>XML_STATUS_SUSPENDED</code>. 1209220ed979SColeman KaneOtherwise, parsing is <em>aborted</em>, that is, <code><a href= 1210220ed979SColeman Kane"#XML_Parse" >XML_Parse</a></code> and <code><a href= 1211220ed979SColeman Kane"#XML_ParseBuffer" >XML_ParseBuffer</a></code> return 1212220ed979SColeman Kane<code>XML_STATUS_ERROR</code> with error code 1213220ed979SColeman Kane<code>XML_ERROR_ABORTED</code>.</p> 1214220ed979SColeman Kane 1215220ed979SColeman Kane<p><strong>Note:</strong> 1216220ed979SColeman KaneThis will be applied to the current parser instance only, that is, if 1217220ed979SColeman Kanethere is a parent parser then it will continue parsing when the 1218220ed979SColeman Kaneexternal entity reference handler returns. It is up to the 1219220ed979SColeman Kaneimplementation of that handler to call <code><a href= 1220220ed979SColeman Kane"#XML_StopParser" >XML_StopParser</a></code> on the parent parser 1221220ed979SColeman Kane(recursively), if one wants to stop parsing altogether.</p> 1222220ed979SColeman Kane 1223220ed979SColeman Kane<p>When suspended, parsing can be resumed by calling <code><a href= 1224220ed979SColeman Kane"#XML_ResumeParser" >XML_ResumeParser</a></code>.</p> 1225220ed979SColeman Kane 1226220ed979SColeman Kane<p>New in Expat 1.95.8.</p> 1227220ed979SColeman Kane</div> 1228220ed979SColeman Kane 1229cc68614dSXin LI<h4 id="XML_ResumeParser">XML_ResumeParser</h4> 1230cc68614dSXin LI<pre class="fcndec"> 1231220ed979SColeman Kaneenum XML_Status XMLCALL 1232220ed979SColeman KaneXML_ResumeParser(XML_Parser p); 1233220ed979SColeman Kane</pre> 1234220ed979SColeman Kane<div class="fcndef"> 1235220ed979SColeman Kane<p>Resumes parsing after it has been suspended with <code><a href= 1236220ed979SColeman Kane"#XML_StopParser" >XML_StopParser</a></code>. Must not be called from 1237220ed979SColeman Kanewithin a handler call-back. Returns same status codes as <code><a 1238220ed979SColeman Kanehref= "#XML_Parse">XML_Parse</a></code> or <code><a href= 1239220ed979SColeman Kane"#XML_ParseBuffer" >XML_ParseBuffer</a></code>. An additional error 1240220ed979SColeman Kanecode, <code>XML_ERROR_NOT_SUSPENDED</code>, will be returned if the 1241220ed979SColeman Kaneparser was not currently suspended.</p> 1242220ed979SColeman Kane 1243220ed979SColeman Kane<p><strong>Note:</strong> 1244220ed979SColeman KaneThis must be called on the most deeply nested child parser instance 1245220ed979SColeman Kanefirst, and on its parent parser only after the child parser has 1246220ed979SColeman Kanefinished, to be applied recursively until the document entity's parser 1247220ed979SColeman Kaneis restarted. That is, the parent parser will not resume by itself 1248220ed979SColeman Kaneand it is up to the application to call <code><a href= 1249220ed979SColeman Kane"#XML_ResumeParser" >XML_ResumeParser</a></code> on it at the 1250220ed979SColeman Kaneappropriate moment.</p> 1251220ed979SColeman Kane 1252220ed979SColeman Kane<p>New in Expat 1.95.8.</p> 1253220ed979SColeman Kane</div> 1254220ed979SColeman Kane 1255cc68614dSXin LI<h4 id="XML_GetParsingStatus">XML_GetParsingStatus</h4> 1256cc68614dSXin LI<pre class="fcndec"> 1257220ed979SColeman Kanevoid XMLCALL 1258220ed979SColeman KaneXML_GetParsingStatus(XML_Parser p, 1259220ed979SColeman Kane XML_ParsingStatus *status); 1260220ed979SColeman Kane</pre> 1261220ed979SColeman Kane<pre class="signature"> 1262220ed979SColeman Kaneenum XML_Parsing { 1263220ed979SColeman Kane XML_INITIALIZED, 1264220ed979SColeman Kane XML_PARSING, 1265220ed979SColeman Kane XML_FINISHED, 1266220ed979SColeman Kane XML_SUSPENDED 1267220ed979SColeman Kane}; 1268220ed979SColeman Kane 1269220ed979SColeman Kanetypedef struct { 1270220ed979SColeman Kane enum XML_Parsing parsing; 1271220ed979SColeman Kane XML_Bool finalBuffer; 1272220ed979SColeman Kane} XML_ParsingStatus; 1273220ed979SColeman Kane</pre> 1274220ed979SColeman Kane<div class="fcndef"> 1275220ed979SColeman Kane<p>Returns status of parser with respect to being initialized, 1276220ed979SColeman Kaneparsing, finished, or suspended, and whether the final buffer is being 1277220ed979SColeman Kaneprocessed. The <code>status</code> parameter <em>must not</em> be 1278220ed979SColeman KaneNULL.</p> 1279220ed979SColeman Kane 1280220ed979SColeman Kane<p>New in Expat 1.95.8.</p> 1281220ed979SColeman Kane</div> 1282220ed979SColeman Kane 1283220ed979SColeman Kane 12845bb6a25fSPoul-Henning Kamp<h3><a name="setting">Handler Setting</a></h3> 12855bb6a25fSPoul-Henning Kamp 12865bb6a25fSPoul-Henning Kamp<p>Although handlers are typically set prior to parsing and left alone, an 12875bb6a25fSPoul-Henning Kampapplication may choose to set or change the handler for a parsing event 12885bb6a25fSPoul-Henning Kampwhile the parse is in progress. For instance, your application may choose 12895bb6a25fSPoul-Henning Kampto ignore all text not descended from a <code>para</code> element. One 12905bb6a25fSPoul-Henning Kampway it could do this is to set the character handler when a para start tag 12915bb6a25fSPoul-Henning Kampis seen, and unset it for the corresponding end tag.</p> 12925bb6a25fSPoul-Henning Kamp 12935bb6a25fSPoul-Henning Kamp<p>A handler may be <em>unset</em> by providing a NULL pointer to the 12945bb6a25fSPoul-Henning Kampappropriate handler setter. None of the handler setting functions have 12955bb6a25fSPoul-Henning Kampa return value.</p> 12965bb6a25fSPoul-Henning Kamp 12975bb6a25fSPoul-Henning Kamp<p>Your handlers will be receiving strings in arrays of type 1298220ed979SColeman Kane<code>XML_Char</code>. This type is conditionally defined in expat.h as 1299220ed979SColeman Kaneeither <code>char</code>, <code>wchar_t</code> or <code>unsigned short</code>. 1300220ed979SColeman KaneThe former implies UTF-8 encoding, the latter two imply UTF-16 encoding. 1301220ed979SColeman KaneNote that you'll receive them in this form independent of the original 1302220ed979SColeman Kaneencoding of the document.</p> 13035bb6a25fSPoul-Henning Kamp 13045bb6a25fSPoul-Henning Kamp<div class="handler"> 1305cc68614dSXin LI<h4 id="XML_SetStartElementHandler">XML_SetStartElementHandler</h4> 1306cc68614dSXin LI<pre class="setter"> 1307220ed979SColeman Kanevoid XMLCALL 13085bb6a25fSPoul-Henning KampXML_SetStartElementHandler(XML_Parser p, 13095bb6a25fSPoul-Henning Kamp XML_StartElementHandler start); 13105bb6a25fSPoul-Henning Kamp</pre> 13115bb6a25fSPoul-Henning Kamp<pre class="signature"> 13125bb6a25fSPoul-Henning Kamptypedef void 1313220ed979SColeman Kane(XMLCALL *XML_StartElementHandler)(void *userData, 13145bb6a25fSPoul-Henning Kamp const XML_Char *name, 13155bb6a25fSPoul-Henning Kamp const XML_Char **atts); 13165bb6a25fSPoul-Henning Kamp</pre> 13175bb6a25fSPoul-Henning Kamp<p>Set handler for start (and empty) tags. Attributes are passed to the start 13185bb6a25fSPoul-Henning Kamphandler as a pointer to a vector of char pointers. Each attribute seen in 13195bb6a25fSPoul-Henning Kampa start (or empty) tag occupies 2 consecutive places in this vector: the 13205bb6a25fSPoul-Henning Kampattribute name followed by the attribute value. These pairs are terminated 13215bb6a25fSPoul-Henning Kampby a null pointer.</p> 13225bb6a25fSPoul-Henning Kamp<p>Note that an empty tag generates a call to both start and end handlers 13235bb6a25fSPoul-Henning Kamp(in that order).</p> 13245bb6a25fSPoul-Henning Kamp</div> 13255bb6a25fSPoul-Henning Kamp 13265bb6a25fSPoul-Henning Kamp<div class="handler"> 1327cc68614dSXin LI<h4 id="XML_SetEndElementHandler">XML_SetEndElementHandler</h4> 1328cc68614dSXin LI<pre class="setter"> 1329220ed979SColeman Kanevoid XMLCALL 13305bb6a25fSPoul-Henning KampXML_SetEndElementHandler(XML_Parser p, 13315bb6a25fSPoul-Henning Kamp XML_EndElementHandler); 13325bb6a25fSPoul-Henning Kamp</pre> 13335bb6a25fSPoul-Henning Kamp<pre class="signature"> 13345bb6a25fSPoul-Henning Kamptypedef void 1335220ed979SColeman Kane(XMLCALL *XML_EndElementHandler)(void *userData, 13365bb6a25fSPoul-Henning Kamp const XML_Char *name); 13375bb6a25fSPoul-Henning Kamp</pre> 13385bb6a25fSPoul-Henning Kamp<p>Set handler for end (and empty) tags. As noted above, an empty tag 13395bb6a25fSPoul-Henning Kampgenerates a call to both start and end handlers.</p> 13405bb6a25fSPoul-Henning Kamp</div> 13415bb6a25fSPoul-Henning Kamp 13425bb6a25fSPoul-Henning Kamp<div class="handler"> 1343cc68614dSXin LI<h4 id="XML_SetElementHandler">XML_SetElementHandler</h4> 1344cc68614dSXin LI<pre class="setter"> 1345220ed979SColeman Kanevoid XMLCALL 13465bb6a25fSPoul-Henning KampXML_SetElementHandler(XML_Parser p, 13475bb6a25fSPoul-Henning Kamp XML_StartElementHandler start, 13485bb6a25fSPoul-Henning Kamp XML_EndElementHandler end); 13495bb6a25fSPoul-Henning Kamp</pre> 13505bb6a25fSPoul-Henning Kamp<p>Set handlers for start and end tags with one call.</p> 13515bb6a25fSPoul-Henning Kamp</div> 13525bb6a25fSPoul-Henning Kamp 13535bb6a25fSPoul-Henning Kamp<div class="handler"> 1354cc68614dSXin LI<h4 id="XML_SetCharacterDataHandler">XML_SetCharacterDataHandler</h4> 1355cc68614dSXin LI<pre class="setter"> 1356220ed979SColeman Kanevoid XMLCALL 13575bb6a25fSPoul-Henning KampXML_SetCharacterDataHandler(XML_Parser p, 13585bb6a25fSPoul-Henning Kamp XML_CharacterDataHandler charhndl) 13595bb6a25fSPoul-Henning Kamp</pre> 13605bb6a25fSPoul-Henning Kamp<pre class="signature"> 13615bb6a25fSPoul-Henning Kamptypedef void 1362220ed979SColeman Kane(XMLCALL *XML_CharacterDataHandler)(void *userData, 13635bb6a25fSPoul-Henning Kamp const XML_Char *s, 13645bb6a25fSPoul-Henning Kamp int len); 13655bb6a25fSPoul-Henning Kamp</pre> 13665bb6a25fSPoul-Henning Kamp<p>Set a text handler. The string your handler receives 1367cc68614dSXin LIis <em>NOT null-terminated</em>. You have to use the length argument 13685bb6a25fSPoul-Henning Kampto deal with the end of the string. A single block of contiguous text 13695bb6a25fSPoul-Henning Kampfree of markup may still result in a sequence of calls to this handler. 13705bb6a25fSPoul-Henning KampIn other words, if you're searching for a pattern in the text, it may 1371220ed979SColeman Kanebe split across calls to this handler. Note: Setting this handler to NULL 1372220ed979SColeman Kanemay <em>NOT immediately</em> terminate call-backs if the parser is currently 1373220ed979SColeman Kaneprocessing such a single block of contiguous markup-free text, as the parser 1374220ed979SColeman Kanewill continue calling back until the end of the block is reached.</p> 13755bb6a25fSPoul-Henning Kamp</div> 13765bb6a25fSPoul-Henning Kamp 13775bb6a25fSPoul-Henning Kamp<div class="handler"> 1378cc68614dSXin LI<h4 id="XML_SetProcessingInstructionHandler">XML_SetProcessingInstructionHandler</h4> 1379cc68614dSXin LI<pre class="setter"> 1380220ed979SColeman Kanevoid XMLCALL 13815bb6a25fSPoul-Henning KampXML_SetProcessingInstructionHandler(XML_Parser p, 13825bb6a25fSPoul-Henning Kamp XML_ProcessingInstructionHandler proc) 13835bb6a25fSPoul-Henning Kamp</pre> 13845bb6a25fSPoul-Henning Kamp<pre class="signature"> 13855bb6a25fSPoul-Henning Kamptypedef void 1386220ed979SColeman Kane(XMLCALL *XML_ProcessingInstructionHandler)(void *userData, 13875bb6a25fSPoul-Henning Kamp const XML_Char *target, 13885bb6a25fSPoul-Henning Kamp const XML_Char *data); 13895bb6a25fSPoul-Henning Kamp 13905bb6a25fSPoul-Henning Kamp</pre> 13915bb6a25fSPoul-Henning Kamp<p>Set a handler for processing instructions. The target is the first word 13925bb6a25fSPoul-Henning Kampin the processing instruction. The data is the rest of the characters in 13935bb6a25fSPoul-Henning Kampit after skipping all whitespace after the initial word.</p> 13945bb6a25fSPoul-Henning Kamp</div> 13955bb6a25fSPoul-Henning Kamp 13965bb6a25fSPoul-Henning Kamp<div class="handler"> 1397cc68614dSXin LI<h4 id="XML_SetCommentHandler">XML_SetCommentHandler</h4> 1398cc68614dSXin LI<pre class="setter"> 1399220ed979SColeman Kanevoid XMLCALL 14005bb6a25fSPoul-Henning KampXML_SetCommentHandler(XML_Parser p, 14015bb6a25fSPoul-Henning Kamp XML_CommentHandler cmnt) 14025bb6a25fSPoul-Henning Kamp</pre> 14035bb6a25fSPoul-Henning Kamp<pre class="signature"> 14045bb6a25fSPoul-Henning Kamptypedef void 1405220ed979SColeman Kane(XMLCALL *XML_CommentHandler)(void *userData, 14065bb6a25fSPoul-Henning Kamp const XML_Char *data); 14075bb6a25fSPoul-Henning Kamp</pre> 14085bb6a25fSPoul-Henning Kamp<p>Set a handler for comments. The data is all text inside the comment 14095bb6a25fSPoul-Henning Kampdelimiters.</p> 14105bb6a25fSPoul-Henning Kamp</div> 14115bb6a25fSPoul-Henning Kamp 14125bb6a25fSPoul-Henning Kamp<div class="handler"> 1413cc68614dSXin LI<h4 id="XML_SetStartCdataSectionHandler">XML_SetStartCdataSectionHandler</h4> 1414cc68614dSXin LI<pre class="setter"> 1415220ed979SColeman Kanevoid XMLCALL 14165bb6a25fSPoul-Henning KampXML_SetStartCdataSectionHandler(XML_Parser p, 14175bb6a25fSPoul-Henning Kamp XML_StartCdataSectionHandler start); 14185bb6a25fSPoul-Henning Kamp</pre> 14195bb6a25fSPoul-Henning Kamp<pre class="signature"> 14205bb6a25fSPoul-Henning Kamptypedef void 1421220ed979SColeman Kane(XMLCALL *XML_StartCdataSectionHandler)(void *userData); 14225bb6a25fSPoul-Henning Kamp</pre> 14235bb6a25fSPoul-Henning Kamp<p>Set a handler that gets called at the beginning of a CDATA section.</p> 14245bb6a25fSPoul-Henning Kamp</div> 14255bb6a25fSPoul-Henning Kamp 14265bb6a25fSPoul-Henning Kamp<div class="handler"> 1427cc68614dSXin LI<h4 id="XML_SetEndCdataSectionHandler">XML_SetEndCdataSectionHandler</h4> 1428cc68614dSXin LI<pre class="setter"> 1429220ed979SColeman Kanevoid XMLCALL 14305bb6a25fSPoul-Henning KampXML_SetEndCdataSectionHandler(XML_Parser p, 14315bb6a25fSPoul-Henning Kamp XML_EndCdataSectionHandler end); 14325bb6a25fSPoul-Henning Kamp</pre> 14335bb6a25fSPoul-Henning Kamp<pre class="signature"> 14345bb6a25fSPoul-Henning Kamptypedef void 1435220ed979SColeman Kane(XMLCALL *XML_EndCdataSectionHandler)(void *userData); 14365bb6a25fSPoul-Henning Kamp</pre> 14375bb6a25fSPoul-Henning Kamp<p>Set a handler that gets called at the end of a CDATA section.</p> 14385bb6a25fSPoul-Henning Kamp</div> 14395bb6a25fSPoul-Henning Kamp 14405bb6a25fSPoul-Henning Kamp<div class="handler"> 1441cc68614dSXin LI<h4 id="XML_SetCdataSectionHandler">XML_SetCdataSectionHandler</h4> 1442cc68614dSXin LI<pre class="setter"> 1443220ed979SColeman Kanevoid XMLCALL 14445bb6a25fSPoul-Henning KampXML_SetCdataSectionHandler(XML_Parser p, 14455bb6a25fSPoul-Henning Kamp XML_StartCdataSectionHandler start, 14465bb6a25fSPoul-Henning Kamp XML_EndCdataSectionHandler end) 14475bb6a25fSPoul-Henning Kamp</pre> 14485bb6a25fSPoul-Henning Kamp<p>Sets both CDATA section handlers with one call.</p> 14495bb6a25fSPoul-Henning Kamp</div> 14505bb6a25fSPoul-Henning Kamp 14515bb6a25fSPoul-Henning Kamp<div class="handler"> 1452cc68614dSXin LI<h4 id="XML_SetDefaultHandler">XML_SetDefaultHandler</h4> 1453cc68614dSXin LI<pre class="setter"> 1454220ed979SColeman Kanevoid XMLCALL 14555bb6a25fSPoul-Henning KampXML_SetDefaultHandler(XML_Parser p, 14565bb6a25fSPoul-Henning Kamp XML_DefaultHandler hndl) 14575bb6a25fSPoul-Henning Kamp</pre> 14585bb6a25fSPoul-Henning Kamp<pre class="signature"> 14595bb6a25fSPoul-Henning Kamptypedef void 1460220ed979SColeman Kane(XMLCALL *XML_DefaultHandler)(void *userData, 14615bb6a25fSPoul-Henning Kamp const XML_Char *s, 14625bb6a25fSPoul-Henning Kamp int len); 14635bb6a25fSPoul-Henning Kamp</pre> 14645bb6a25fSPoul-Henning Kamp 14655bb6a25fSPoul-Henning Kamp<p>Sets a handler for any characters in the document which wouldn't 14665bb6a25fSPoul-Henning Kampotherwise be handled. This includes both data for which no handlers 14675bb6a25fSPoul-Henning Kampcan be set (like some kinds of DTD declarations) and data which could 14685bb6a25fSPoul-Henning Kampbe reported but which currently has no handler set. The characters 14695bb6a25fSPoul-Henning Kampare passed exactly as they were present in the XML document except 14705bb6a25fSPoul-Henning Kampthat they will be encoded in UTF-8 or UTF-16. Line boundaries are not 14715bb6a25fSPoul-Henning Kampnormalized. Note that a byte order mark character is not passed to the 14725bb6a25fSPoul-Henning Kampdefault handler. There are no guarantees about how characters are 14735bb6a25fSPoul-Henning Kampdivided between calls to the default handler: for example, a comment 14745bb6a25fSPoul-Henning Kampmight be split between multiple calls. Setting the handler with 14755bb6a25fSPoul-Henning Kampthis call has the side effect of turning off expansion of references 14765bb6a25fSPoul-Henning Kampto internally defined general entities. Instead these references are 14775bb6a25fSPoul-Henning Kamppassed to the default handler.</p> 14785bb6a25fSPoul-Henning Kamp 14795bb6a25fSPoul-Henning Kamp<p>See also <code><a 14805bb6a25fSPoul-Henning Kamphref="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p> 14815bb6a25fSPoul-Henning Kamp</div> 14825bb6a25fSPoul-Henning Kamp 14835bb6a25fSPoul-Henning Kamp<div class="handler"> 1484cc68614dSXin LI<h4 id="XML_SetDefaultHandlerExpand">XML_SetDefaultHandlerExpand</h4> 1485cc68614dSXin LI<pre class="setter"> 1486220ed979SColeman Kanevoid XMLCALL 14875bb6a25fSPoul-Henning KampXML_SetDefaultHandlerExpand(XML_Parser p, 14885bb6a25fSPoul-Henning Kamp XML_DefaultHandler hndl) 14895bb6a25fSPoul-Henning Kamp</pre> 14905bb6a25fSPoul-Henning Kamp<pre class="signature"> 14915bb6a25fSPoul-Henning Kamptypedef void 1492220ed979SColeman Kane(XMLCALL *XML_DefaultHandler)(void *userData, 14935bb6a25fSPoul-Henning Kamp const XML_Char *s, 14945bb6a25fSPoul-Henning Kamp int len); 14955bb6a25fSPoul-Henning Kamp</pre> 14965bb6a25fSPoul-Henning Kamp<p>This sets a default handler, but doesn't inhibit the expansion of 14975bb6a25fSPoul-Henning Kampinternal entity references. The entity reference will not be passed 14985bb6a25fSPoul-Henning Kampto the default handler.</p> 14995bb6a25fSPoul-Henning Kamp 15005bb6a25fSPoul-Henning Kamp<p>See also <code><a 15015bb6a25fSPoul-Henning Kamphref="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p> 15025bb6a25fSPoul-Henning Kamp</div> 15035bb6a25fSPoul-Henning Kamp 15045bb6a25fSPoul-Henning Kamp<div class="handler"> 1505cc68614dSXin LI<h4 id="XML_SetExternalEntityRefHandler">XML_SetExternalEntityRefHandler</h4> 1506cc68614dSXin LI<pre class="setter"> 1507220ed979SColeman Kanevoid XMLCALL 15085bb6a25fSPoul-Henning KampXML_SetExternalEntityRefHandler(XML_Parser p, 15095bb6a25fSPoul-Henning Kamp XML_ExternalEntityRefHandler hndl) 15105bb6a25fSPoul-Henning Kamp</pre> 15115bb6a25fSPoul-Henning Kamp<pre class="signature"> 15125bb6a25fSPoul-Henning Kamptypedef int 1513220ed979SColeman Kane(XMLCALL *XML_ExternalEntityRefHandler)(XML_Parser p, 15145bb6a25fSPoul-Henning Kamp const XML_Char *context, 15155bb6a25fSPoul-Henning Kamp const XML_Char *base, 15165bb6a25fSPoul-Henning Kamp const XML_Char *systemId, 15175bb6a25fSPoul-Henning Kamp const XML_Char *publicId); 15185bb6a25fSPoul-Henning Kamp</pre> 15195bb6a25fSPoul-Henning Kamp<p>Set an external entity reference handler. This handler is also 15205bb6a25fSPoul-Henning Kampcalled for processing an external DTD subset if parameter entity parsing 15215bb6a25fSPoul-Henning Kampis in effect. (See <a href="#XML_SetParamEntityParsing"> 15225bb6a25fSPoul-Henning Kamp<code>XML_SetParamEntityParsing</code></a>.)</p> 15235bb6a25fSPoul-Henning Kamp 1524220ed979SColeman Kane<p>The <code>context</code> parameter specifies the parsing context in 1525220ed979SColeman Kanethe format expected by the <code>context</code> argument to <code><a 1526220ed979SColeman Kanehref="#XML_ExternalEntityParserCreate" 1527220ed979SColeman Kane>XML_ExternalEntityParserCreate</a></code>. <code>code</code> is 1528220ed979SColeman Kanevalid only until the handler returns, so if the referenced entity is 1529220ed979SColeman Kaneto be parsed later, it must be copied. <code>context</code> is NULL 1530220ed979SColeman Kaneonly when the entity is a parameter entity, which is how one can 1531220ed979SColeman Kanedifferentiate between general and parameter entities.</p> 15325bb6a25fSPoul-Henning Kamp 1533220ed979SColeman Kane<p>The <code>base</code> parameter is the base to use for relative 1534220ed979SColeman Kanesystem identifiers. It is set by <code><a 1535220ed979SColeman Kanehref="#XML_SetBase">XML_SetBase</a></code> and may be NULL. The 1536220ed979SColeman Kane<code>publicId</code> parameter is the public id given in the entity 1537220ed979SColeman Kanedeclaration and may be NULL. <code>systemId</code> is the system 1538220ed979SColeman Kaneidentifier specified in the entity declaration and is never NULL.</p> 15395bb6a25fSPoul-Henning Kamp 1540220ed979SColeman Kane<p>There are a couple of ways in which this handler differs from 1541220ed979SColeman Kaneothers. First, this handler returns a status indicator (an 1542220ed979SColeman Kaneinteger). <code>XML_STATUS_OK</code> should be returned for successful 1543220ed979SColeman Kanehandling of the external entity reference. Returning 1544220ed979SColeman Kane<code>XML_STATUS_ERROR</code> indicates failure, and causes the 1545220ed979SColeman Kanecalling parser to return an 1546220ed979SColeman Kane<code>XML_ERROR_EXTERNAL_ENTITY_HANDLING</code> error.</p> 15475bb6a25fSPoul-Henning Kamp 1548220ed979SColeman Kane<p>Second, instead of having the user data as its first argument, it 1549220ed979SColeman Kanereceives the parser that encountered the entity reference. This, along 1550220ed979SColeman Kanewith the context parameter, may be used as arguments to a call to 1551220ed979SColeman Kane<code><a href= "#XML_ExternalEntityParserCreate" 1552220ed979SColeman Kane>XML_ExternalEntityParserCreate</a></code>. Using the returned 1553220ed979SColeman Kaneparser, the body of the external entity can be recursively parsed.</p> 15545bb6a25fSPoul-Henning Kamp 15555bb6a25fSPoul-Henning Kamp<p>Since this handler may be called recursively, it should not be saving 15565bb6a25fSPoul-Henning Kampinformation into global or static variables.</p> 15575bb6a25fSPoul-Henning Kamp</div> 15585bb6a25fSPoul-Henning Kamp 1559cc68614dSXin LI<h4 id="XML_SetExternalEntityRefHandlerArg">XML_SetExternalEntityRefHandlerArg</h4> 1560cc68614dSXin LI<pre class="fcndec"> 1561220ed979SColeman Kanevoid XMLCALL 1562220ed979SColeman KaneXML_SetExternalEntityRefHandlerArg(XML_Parser p, 1563220ed979SColeman Kane void *arg) 1564220ed979SColeman Kane</pre> 1565220ed979SColeman Kane<div class="fcndef"> 1566220ed979SColeman Kane<p>Set the argument passed to the ExternalEntityRefHandler. If 1567220ed979SColeman Kane<code>arg</code> is not NULL, it is the new value passed to the 1568220ed979SColeman Kanehandler set using <code><a href="#XML_SetExternalEntityRefHandler" 1569220ed979SColeman Kane>XML_SetExternalEntityRefHandler</a></code>; if <code>arg</code> is 1570220ed979SColeman KaneNULL, the argument passed to the handler function will be the parser 1571220ed979SColeman Kaneobject itself.</p> 1572220ed979SColeman Kane 1573220ed979SColeman Kane<p><strong>Note:</strong> 1574220ed979SColeman KaneThe type of <code>arg</code> and the type of the first argument to the 1575220ed979SColeman KaneExternalEntityRefHandler do not match. This function takes a 1576220ed979SColeman Kane<code>void *</code> to be passed to the handler, while the handler 1577220ed979SColeman Kaneaccepts an <code>XML_Parser</code>. This is a historical accident, 1578220ed979SColeman Kanebut will not be corrected before Expat 2.0 (at the earliest) to avoid 1579220ed979SColeman Kanecausing compiler warnings for code that's known to work with this 1580220ed979SColeman KaneAPI. It is the responsibility of the application code to know the 1581220ed979SColeman Kaneactual type of the argument passed to the handler and to manage it 1582220ed979SColeman Kaneproperly.</p> 1583220ed979SColeman Kane</div> 1584220ed979SColeman Kane 15855bb6a25fSPoul-Henning Kamp<div class="handler"> 1586cc68614dSXin LI<h4 id="XML_SetSkippedEntityHandler">XML_SetSkippedEntityHandler</h4> 1587cc68614dSXin LI<pre class="setter"> 1588220ed979SColeman Kanevoid XMLCALL 15895bb6a25fSPoul-Henning KampXML_SetSkippedEntityHandler(XML_Parser p, 15905bb6a25fSPoul-Henning Kamp XML_SkippedEntityHandler handler) 15915bb6a25fSPoul-Henning Kamp</pre> 15925bb6a25fSPoul-Henning Kamp<pre class="signature"> 15935bb6a25fSPoul-Henning Kamptypedef void 1594220ed979SColeman Kane(XMLCALL *XML_SkippedEntityHandler)(void *userData, 15955bb6a25fSPoul-Henning Kamp const XML_Char *entityName, 15965bb6a25fSPoul-Henning Kamp int is_parameter_entity); 15975bb6a25fSPoul-Henning Kamp</pre> 15985bb6a25fSPoul-Henning Kamp<p>Set a skipped entity handler. This is called in two situations:</p> 15995bb6a25fSPoul-Henning Kamp<ol> 16005bb6a25fSPoul-Henning Kamp <li>An entity reference is encountered for which no declaration 16015bb6a25fSPoul-Henning Kamp has been read <em>and</em> this is not an error.</li> 16025bb6a25fSPoul-Henning Kamp <li>An internal entity reference is read, but not expanded, because 16035bb6a25fSPoul-Henning Kamp <a href="#XML_SetDefaultHandler"><code>XML_SetDefaultHandler</code></a> 16045bb6a25fSPoul-Henning Kamp has been called.</li> 16055bb6a25fSPoul-Henning Kamp</ol> 16065bb6a25fSPoul-Henning Kamp<p>The <code>is_parameter_entity</code> argument will be non-zero for 1607cc68614dSXin LIa parameter entity and zero for a general entity.</p> <p>Note: Skipped 16085bb6a25fSPoul-Henning Kampparameter entities in declarations and skipped general entities in 16095bb6a25fSPoul-Henning Kampattribute values cannot be reported, because the event would be out of 16105bb6a25fSPoul-Henning Kampsync with the reporting of the declarations or attribute values</p> 16115bb6a25fSPoul-Henning Kamp</div> 16125bb6a25fSPoul-Henning Kamp 16135bb6a25fSPoul-Henning Kamp<div class="handler"> 1614cc68614dSXin LI<h4 id="XML_SetUnknownEncodingHandler">XML_SetUnknownEncodingHandler</h4> 1615cc68614dSXin LI<pre class="setter"> 1616220ed979SColeman Kanevoid XMLCALL 16175bb6a25fSPoul-Henning KampXML_SetUnknownEncodingHandler(XML_Parser p, 16185bb6a25fSPoul-Henning Kamp XML_UnknownEncodingHandler enchandler, 16195bb6a25fSPoul-Henning Kamp void *encodingHandlerData) 16205bb6a25fSPoul-Henning Kamp</pre> 16215bb6a25fSPoul-Henning Kamp<pre class="signature"> 16225bb6a25fSPoul-Henning Kamptypedef int 1623220ed979SColeman Kane(XMLCALL *XML_UnknownEncodingHandler)(void *encodingHandlerData, 16245bb6a25fSPoul-Henning Kamp const XML_Char *name, 16255bb6a25fSPoul-Henning Kamp XML_Encoding *info); 16265bb6a25fSPoul-Henning Kamp 16275bb6a25fSPoul-Henning Kamptypedef struct { 16285bb6a25fSPoul-Henning Kamp int map[256]; 16295bb6a25fSPoul-Henning Kamp void *data; 1630220ed979SColeman Kane int (XMLCALL *convert)(void *data, const char *s); 1631220ed979SColeman Kane void (XMLCALL *release)(void *data); 16325bb6a25fSPoul-Henning Kamp} XML_Encoding; 16335bb6a25fSPoul-Henning Kamp</pre> 1634220ed979SColeman Kane<p>Set a handler to deal with encodings other than the <a 1635220ed979SColeman Kanehref="#builtin_encodings">built in set</a>. This should be done before 16365bb6a25fSPoul-Henning Kamp<code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a href= 16375bb6a25fSPoul-Henning Kamp"#XML_ParseBuffer" >XML_ParseBuffer</a></code> have been called on the 1638220ed979SColeman Kanegiven parser.</p> <p>If the handler knows how to deal with an encoding 1639220ed979SColeman Kanewith the given name, it should fill in the <code>info</code> data 1640220ed979SColeman Kanestructure and return <code>XML_STATUS_OK</code>. Otherwise it 1641220ed979SColeman Kaneshould return <code>XML_STATUS_ERROR</code>. The handler will be called 1642220ed979SColeman Kaneat most once per parsed (external) entity. The optional application 1643220ed979SColeman Kanedata pointer <code>encodingHandlerData</code> will be passed back to 1644220ed979SColeman Kanethe handler.</p> 16455bb6a25fSPoul-Henning Kamp 16460a48773fSEric van Gyzen<p>The map array contains information for every possible leading 16475bb6a25fSPoul-Henning Kampbyte in a byte sequence. If the corresponding value is >= 0, then it's 16485bb6a25fSPoul-Henning Kampa single byte sequence and the byte encodes that Unicode value. If the 16495bb6a25fSPoul-Henning Kampvalue is -1, then that byte is invalid as the initial byte in a sequence. 16505bb6a25fSPoul-Henning KampIf the value is -n, where n is an integer > 1, then n is the number of 16515bb6a25fSPoul-Henning Kampbytes in the sequence and the actual conversion is accomplished by a 16525bb6a25fSPoul-Henning Kampcall to the function pointed at by convert. This function may return -1 16535bb6a25fSPoul-Henning Kampif the sequence itself is invalid. The convert pointer may be null if 16545bb6a25fSPoul-Henning Kampthere are only single byte codes. The data parameter passed to the convert 16555bb6a25fSPoul-Henning Kampfunction is the data pointer from <code>XML_Encoding</code>. The 1656cc68614dSXin LIstring s is <em>NOT</em> null-terminated and points at the sequence of 16575bb6a25fSPoul-Henning Kampbytes to be converted.</p> 16585bb6a25fSPoul-Henning Kamp 16595bb6a25fSPoul-Henning Kamp<p>The function pointed at by <code>release</code> is called by the 16605bb6a25fSPoul-Henning Kampparser when it is finished with the encoding. It may be NULL.</p> 16615bb6a25fSPoul-Henning Kamp</div> 16625bb6a25fSPoul-Henning Kamp 16635bb6a25fSPoul-Henning Kamp<div class="handler"> 1664cc68614dSXin LI<h4 id="XML_SetStartNamespaceDeclHandler">XML_SetStartNamespaceDeclHandler</h4> 1665cc68614dSXin LI<pre class="setter"> 1666220ed979SColeman Kanevoid XMLCALL 16675bb6a25fSPoul-Henning KampXML_SetStartNamespaceDeclHandler(XML_Parser p, 16685bb6a25fSPoul-Henning Kamp XML_StartNamespaceDeclHandler start); 16695bb6a25fSPoul-Henning Kamp</pre> 16705bb6a25fSPoul-Henning Kamp<pre class="signature"> 16715bb6a25fSPoul-Henning Kamptypedef void 1672220ed979SColeman Kane(XMLCALL *XML_StartNamespaceDeclHandler)(void *userData, 16735bb6a25fSPoul-Henning Kamp const XML_Char *prefix, 16745bb6a25fSPoul-Henning Kamp const XML_Char *uri); 16755bb6a25fSPoul-Henning Kamp</pre> 16765bb6a25fSPoul-Henning Kamp<p>Set a handler to be called when a namespace is declared. Namespace 16775bb6a25fSPoul-Henning Kampdeclarations occur inside start tags. But the namespace declaration start 16785bb6a25fSPoul-Henning Kamphandler is called before the start tag handler for each namespace declared 16795bb6a25fSPoul-Henning Kampin that start tag.</p> 16805bb6a25fSPoul-Henning Kamp</div> 16815bb6a25fSPoul-Henning Kamp 16825bb6a25fSPoul-Henning Kamp<div class="handler"> 1683cc68614dSXin LI<h4 id="XML_SetEndNamespaceDeclHandler">XML_SetEndNamespaceDeclHandler</h4> 1684cc68614dSXin LI<pre class="setter"> 1685220ed979SColeman Kanevoid XMLCALL 16865bb6a25fSPoul-Henning KampXML_SetEndNamespaceDeclHandler(XML_Parser p, 16875bb6a25fSPoul-Henning Kamp XML_EndNamespaceDeclHandler end); 16885bb6a25fSPoul-Henning Kamp</pre> 16895bb6a25fSPoul-Henning Kamp<pre class="signature"> 16905bb6a25fSPoul-Henning Kamptypedef void 1691220ed979SColeman Kane(XMLCALL *XML_EndNamespaceDeclHandler)(void *userData, 16925bb6a25fSPoul-Henning Kamp const XML_Char *prefix); 16935bb6a25fSPoul-Henning Kamp</pre> 16945bb6a25fSPoul-Henning Kamp<p>Set a handler to be called when leaving the scope of a namespace 16955bb6a25fSPoul-Henning Kampdeclaration. This will be called, for each namespace declaration, 16965bb6a25fSPoul-Henning Kampafter the handler for the end tag of the element in which the 16975bb6a25fSPoul-Henning Kampnamespace was declared.</p> 16985bb6a25fSPoul-Henning Kamp</div> 16995bb6a25fSPoul-Henning Kamp 17005bb6a25fSPoul-Henning Kamp<div class="handler"> 1701cc68614dSXin LI<h4 id="XML_SetNamespaceDeclHandler">XML_SetNamespaceDeclHandler</h4> 1702cc68614dSXin LI<pre class="setter"> 1703220ed979SColeman Kanevoid XMLCALL 17045bb6a25fSPoul-Henning KampXML_SetNamespaceDeclHandler(XML_Parser p, 17055bb6a25fSPoul-Henning Kamp XML_StartNamespaceDeclHandler start, 17065bb6a25fSPoul-Henning Kamp XML_EndNamespaceDeclHandler end) 17075bb6a25fSPoul-Henning Kamp</pre> 1708220ed979SColeman Kane<p>Sets both namespace declaration handlers with a single call.</p> 17095bb6a25fSPoul-Henning Kamp</div> 17105bb6a25fSPoul-Henning Kamp 17115bb6a25fSPoul-Henning Kamp<div class="handler"> 1712cc68614dSXin LI<h4 id="XML_SetXmlDeclHandler">XML_SetXmlDeclHandler</h4> 1713cc68614dSXin LI<pre class="setter"> 1714220ed979SColeman Kanevoid XMLCALL 17155bb6a25fSPoul-Henning KampXML_SetXmlDeclHandler(XML_Parser p, 17165bb6a25fSPoul-Henning Kamp XML_XmlDeclHandler xmldecl); 17175bb6a25fSPoul-Henning Kamp</pre> 17185bb6a25fSPoul-Henning Kamp<pre class="signature"> 17195bb6a25fSPoul-Henning Kamptypedef void 1720220ed979SColeman Kane(XMLCALL *XML_XmlDeclHandler)(void *userData, 17215bb6a25fSPoul-Henning Kamp const XML_Char *version, 17225bb6a25fSPoul-Henning Kamp const XML_Char *encoding, 17235bb6a25fSPoul-Henning Kamp int standalone); 17245bb6a25fSPoul-Henning Kamp</pre> 17255bb6a25fSPoul-Henning Kamp<p>Sets a handler that is called for XML declarations and also for 17265bb6a25fSPoul-Henning Kamptext declarations discovered in external entities. The way to 17275bb6a25fSPoul-Henning Kampdistinguish is that the <code>version</code> parameter will be NULL 17285bb6a25fSPoul-Henning Kampfor text declarations. The <code>encoding</code> parameter may be NULL 17295bb6a25fSPoul-Henning Kampfor an XML declaration. The <code>standalone</code> argument will 17305bb6a25fSPoul-Henning Kampcontain -1, 0, or 1 indicating respectively that there was no 17315bb6a25fSPoul-Henning Kampstandalone parameter in the declaration, that it was given as no, or 17325bb6a25fSPoul-Henning Kampthat it was given as yes.</p> 17335bb6a25fSPoul-Henning Kamp</div> 17345bb6a25fSPoul-Henning Kamp 17355bb6a25fSPoul-Henning Kamp<div class="handler"> 1736cc68614dSXin LI<h4 id="XML_SetStartDoctypeDeclHandler">XML_SetStartDoctypeDeclHandler</h4> 1737cc68614dSXin LI<pre class="setter"> 1738220ed979SColeman Kanevoid XMLCALL 17395bb6a25fSPoul-Henning KampXML_SetStartDoctypeDeclHandler(XML_Parser p, 17405bb6a25fSPoul-Henning Kamp XML_StartDoctypeDeclHandler start); 17415bb6a25fSPoul-Henning Kamp</pre> 17425bb6a25fSPoul-Henning Kamp<pre class="signature"> 17435bb6a25fSPoul-Henning Kamptypedef void 1744220ed979SColeman Kane(XMLCALL *XML_StartDoctypeDeclHandler)(void *userData, 17455bb6a25fSPoul-Henning Kamp const XML_Char *doctypeName, 17465bb6a25fSPoul-Henning Kamp const XML_Char *sysid, 17475bb6a25fSPoul-Henning Kamp const XML_Char *pubid, 17485bb6a25fSPoul-Henning Kamp int has_internal_subset); 17495bb6a25fSPoul-Henning Kamp</pre> 17505bb6a25fSPoul-Henning Kamp<p>Set a handler that is called at the start of a DOCTYPE declaration, 17515bb6a25fSPoul-Henning Kampbefore any external or internal subset is parsed. Both <code>sysid</code> 17525bb6a25fSPoul-Henning Kampand <code>pubid</code> may be NULL. The <code>has_internal_subset</code> 17535bb6a25fSPoul-Henning Kampwill be non-zero if the DOCTYPE declaration has an internal subset.</p> 17545bb6a25fSPoul-Henning Kamp</div> 17555bb6a25fSPoul-Henning Kamp 17565bb6a25fSPoul-Henning Kamp<div class="handler"> 1757cc68614dSXin LI<h4 id="XML_SetEndDoctypeDeclHandler">XML_SetEndDoctypeDeclHandler</h4> 1758cc68614dSXin LI<pre class="setter"> 1759220ed979SColeman Kanevoid XMLCALL 17605bb6a25fSPoul-Henning KampXML_SetEndDoctypeDeclHandler(XML_Parser p, 17615bb6a25fSPoul-Henning Kamp XML_EndDoctypeDeclHandler end); 17625bb6a25fSPoul-Henning Kamp</pre> 17635bb6a25fSPoul-Henning Kamp<pre class="signature"> 17645bb6a25fSPoul-Henning Kamptypedef void 1765220ed979SColeman Kane(XMLCALL *XML_EndDoctypeDeclHandler)(void *userData); 17665bb6a25fSPoul-Henning Kamp</pre> 17675bb6a25fSPoul-Henning Kamp<p>Set a handler that is called at the end of a DOCTYPE declaration, 17685bb6a25fSPoul-Henning Kampafter parsing any external subset.</p> 17695bb6a25fSPoul-Henning Kamp</div> 17705bb6a25fSPoul-Henning Kamp 17715bb6a25fSPoul-Henning Kamp<div class="handler"> 1772cc68614dSXin LI<h4 id="XML_SetDoctypeDeclHandler">XML_SetDoctypeDeclHandler</h4> 1773cc68614dSXin LI<pre class="setter"> 1774220ed979SColeman Kanevoid XMLCALL 17755bb6a25fSPoul-Henning KampXML_SetDoctypeDeclHandler(XML_Parser p, 17765bb6a25fSPoul-Henning Kamp XML_StartDoctypeDeclHandler start, 17775bb6a25fSPoul-Henning Kamp XML_EndDoctypeDeclHandler end); 17785bb6a25fSPoul-Henning Kamp</pre> 17795bb6a25fSPoul-Henning Kamp<p>Set both doctype handlers with one call.</p> 17805bb6a25fSPoul-Henning Kamp</div> 17815bb6a25fSPoul-Henning Kamp 17825bb6a25fSPoul-Henning Kamp<div class="handler"> 1783cc68614dSXin LI<h4 id="XML_SetElementDeclHandler">XML_SetElementDeclHandler</h4> 1784cc68614dSXin LI<pre class="setter"> 1785220ed979SColeman Kanevoid XMLCALL 17865bb6a25fSPoul-Henning KampXML_SetElementDeclHandler(XML_Parser p, 17875bb6a25fSPoul-Henning Kamp XML_ElementDeclHandler eldecl); 17885bb6a25fSPoul-Henning Kamp</pre> 17895bb6a25fSPoul-Henning Kamp<pre class="signature"> 17905bb6a25fSPoul-Henning Kamptypedef void 1791220ed979SColeman Kane(XMLCALL *XML_ElementDeclHandler)(void *userData, 17925bb6a25fSPoul-Henning Kamp const XML_Char *name, 17935bb6a25fSPoul-Henning Kamp XML_Content *model); 17945bb6a25fSPoul-Henning Kamp</pre> 17955bb6a25fSPoul-Henning Kamp<pre class="signature"> 17965bb6a25fSPoul-Henning Kampenum XML_Content_Type { 17975bb6a25fSPoul-Henning Kamp XML_CTYPE_EMPTY = 1, 17985bb6a25fSPoul-Henning Kamp XML_CTYPE_ANY, 17995bb6a25fSPoul-Henning Kamp XML_CTYPE_MIXED, 18005bb6a25fSPoul-Henning Kamp XML_CTYPE_NAME, 18015bb6a25fSPoul-Henning Kamp XML_CTYPE_CHOICE, 18025bb6a25fSPoul-Henning Kamp XML_CTYPE_SEQ 18035bb6a25fSPoul-Henning Kamp}; 18045bb6a25fSPoul-Henning Kamp 18055bb6a25fSPoul-Henning Kampenum XML_Content_Quant { 18065bb6a25fSPoul-Henning Kamp XML_CQUANT_NONE, 18075bb6a25fSPoul-Henning Kamp XML_CQUANT_OPT, 18085bb6a25fSPoul-Henning Kamp XML_CQUANT_REP, 18095bb6a25fSPoul-Henning Kamp XML_CQUANT_PLUS 18105bb6a25fSPoul-Henning Kamp}; 18115bb6a25fSPoul-Henning Kamp 18125bb6a25fSPoul-Henning Kamptypedef struct XML_cp XML_Content; 18135bb6a25fSPoul-Henning Kamp 18145bb6a25fSPoul-Henning Kampstruct XML_cp { 18155bb6a25fSPoul-Henning Kamp enum XML_Content_Type type; 18165bb6a25fSPoul-Henning Kamp enum XML_Content_Quant quant; 18175bb6a25fSPoul-Henning Kamp const XML_Char * name; 18185bb6a25fSPoul-Henning Kamp unsigned int numchildren; 18195bb6a25fSPoul-Henning Kamp XML_Content * children; 18205bb6a25fSPoul-Henning Kamp}; 18215bb6a25fSPoul-Henning Kamp</pre> 18225bb6a25fSPoul-Henning Kamp<p>Sets a handler for element declarations in a DTD. The handler gets 18235bb6a25fSPoul-Henning Kampcalled with the name of the element in the declaration and a pointer 18247ed8e142SXin LIto a structure that contains the element model. It's the user code's 18257ed8e142SXin LIresponsibility to free model when finished with it. See <code> 18267ed8e142SXin LI<a href="#XML_FreeContentModel">XML_FreeContentModel</a></code>. 18277ed8e142SXin LIThere is no need to free the model from the handler, it can be kept 18287ed8e142SXin LIaround and freed at a later stage.</p> 18295bb6a25fSPoul-Henning Kamp 18305bb6a25fSPoul-Henning Kamp<p>The <code>model</code> argument is the root of a tree of 18315bb6a25fSPoul-Henning Kamp<code>XML_Content</code> nodes. If <code>type</code> equals 18325bb6a25fSPoul-Henning Kamp<code>XML_CTYPE_EMPTY</code> or <code>XML_CTYPE_ANY</code>, then 18335bb6a25fSPoul-Henning Kamp<code>quant</code> will be <code>XML_CQUANT_NONE</code>, and the other 18345bb6a25fSPoul-Henning Kampfields will be zero or NULL. If <code>type</code> is 18355bb6a25fSPoul-Henning Kamp<code>XML_CTYPE_MIXED</code>, then <code>quant</code> will be 18365bb6a25fSPoul-Henning Kamp<code>XML_CQUANT_NONE</code> or <code>XML_CQUANT_REP</code> and 18375bb6a25fSPoul-Henning Kamp<code>numchildren</code> will contain the number of elements that are 18385bb6a25fSPoul-Henning Kampallowed to be mixed in and <code>children</code> points to an array of 18395bb6a25fSPoul-Henning Kamp<code>XML_Content</code> structures that will all have type 18405bb6a25fSPoul-Henning KampXML_CTYPE_NAME with no quantification. Only the root node can be type 18415bb6a25fSPoul-Henning Kamp<code>XML_CTYPE_EMPTY</code>, <code>XML_CTYPE_ANY</code>, or 18425bb6a25fSPoul-Henning Kamp<code>XML_CTYPE_MIXED</code>.</p> 18435bb6a25fSPoul-Henning Kamp 18445bb6a25fSPoul-Henning Kamp<p>For type <code>XML_CTYPE_NAME</code>, the <code>name</code> field 18455bb6a25fSPoul-Henning Kamppoints to the name and the <code>numchildren</code> and 18465bb6a25fSPoul-Henning Kamp<code>children</code> fields will be zero and NULL. The 18475bb6a25fSPoul-Henning Kamp<code>quant</code> field will indicate any quantifiers placed on the 18485bb6a25fSPoul-Henning Kampname.</p> 18495bb6a25fSPoul-Henning Kamp 18505bb6a25fSPoul-Henning Kamp<p>Types <code>XML_CTYPE_CHOICE</code> and <code>XML_CTYPE_SEQ</code> 18515bb6a25fSPoul-Henning Kampindicate a choice or sequence respectively. The 18525bb6a25fSPoul-Henning Kamp<code>numchildren</code> field indicates how many nodes in the choice 18535bb6a25fSPoul-Henning Kampor sequence and <code>children</code> points to the nodes.</p> 18545bb6a25fSPoul-Henning Kamp</div> 18555bb6a25fSPoul-Henning Kamp 18565bb6a25fSPoul-Henning Kamp<div class="handler"> 1857cc68614dSXin LI<h4 id="XML_SetAttlistDeclHandler">XML_SetAttlistDeclHandler</h4> 1858cc68614dSXin LI<pre class="setter"> 1859220ed979SColeman Kanevoid XMLCALL 18605bb6a25fSPoul-Henning KampXML_SetAttlistDeclHandler(XML_Parser p, 18615bb6a25fSPoul-Henning Kamp XML_AttlistDeclHandler attdecl); 18625bb6a25fSPoul-Henning Kamp</pre> 18635bb6a25fSPoul-Henning Kamp<pre class="signature"> 18645bb6a25fSPoul-Henning Kamptypedef void 1865220ed979SColeman Kane(XMLCALL *XML_AttlistDeclHandler)(void *userData, 18665bb6a25fSPoul-Henning Kamp const XML_Char *elname, 18675bb6a25fSPoul-Henning Kamp const XML_Char *attname, 18685bb6a25fSPoul-Henning Kamp const XML_Char *att_type, 18695bb6a25fSPoul-Henning Kamp const XML_Char *dflt, 18705bb6a25fSPoul-Henning Kamp int isrequired); 18715bb6a25fSPoul-Henning Kamp</pre> 18725bb6a25fSPoul-Henning Kamp<p>Set a handler for attlist declarations in the DTD. This handler is 18735bb6a25fSPoul-Henning Kampcalled for <em>each</em> attribute. So a single attlist declaration 18745bb6a25fSPoul-Henning Kampwith multiple attributes declared will generate multiple calls to this 18755bb6a25fSPoul-Henning Kamphandler. The <code>elname</code> parameter returns the name of the 18765bb6a25fSPoul-Henning Kampelement for which the attribute is being declared. The attribute name 18775bb6a25fSPoul-Henning Kampis in the <code>attname</code> parameter. The attribute type is in the 18785bb6a25fSPoul-Henning Kamp<code>att_type</code> parameter. It is the string representing the 18795bb6a25fSPoul-Henning Kamptype in the declaration with whitespace removed.</p> 18805bb6a25fSPoul-Henning Kamp 18815bb6a25fSPoul-Henning Kamp<p>The <code>dflt</code> parameter holds the default value. It will be 18825bb6a25fSPoul-Henning KampNULL in the case of "#IMPLIED" or "#REQUIRED" attributes. You can 18835bb6a25fSPoul-Henning Kampdistinguish these two cases by checking the <code>isrequired</code> 18845bb6a25fSPoul-Henning Kampparameter, which will be true in the case of "#REQUIRED" attributes. 18855bb6a25fSPoul-Henning KampAttributes which are "#FIXED" will have also have a true 18865bb6a25fSPoul-Henning Kamp<code>isrequired</code>, but they will have the non-NULL fixed value 18875bb6a25fSPoul-Henning Kampin the <code>dflt</code> parameter.</p> 18885bb6a25fSPoul-Henning Kamp</div> 18895bb6a25fSPoul-Henning Kamp 18905bb6a25fSPoul-Henning Kamp<div class="handler"> 1891cc68614dSXin LI<h4 id="XML_SetEntityDeclHandler">XML_SetEntityDeclHandler</h4> 1892cc68614dSXin LI<pre class="setter"> 1893220ed979SColeman Kanevoid XMLCALL 18945bb6a25fSPoul-Henning KampXML_SetEntityDeclHandler(XML_Parser p, 18955bb6a25fSPoul-Henning Kamp XML_EntityDeclHandler handler); 18965bb6a25fSPoul-Henning Kamp</pre> 18975bb6a25fSPoul-Henning Kamp<pre class="signature"> 18985bb6a25fSPoul-Henning Kamptypedef void 1899220ed979SColeman Kane(XMLCALL *XML_EntityDeclHandler)(void *userData, 19005bb6a25fSPoul-Henning Kamp const XML_Char *entityName, 19015bb6a25fSPoul-Henning Kamp int is_parameter_entity, 19025bb6a25fSPoul-Henning Kamp const XML_Char *value, 19035bb6a25fSPoul-Henning Kamp int value_length, 19045bb6a25fSPoul-Henning Kamp const XML_Char *base, 19055bb6a25fSPoul-Henning Kamp const XML_Char *systemId, 19065bb6a25fSPoul-Henning Kamp const XML_Char *publicId, 19075bb6a25fSPoul-Henning Kamp const XML_Char *notationName); 19085bb6a25fSPoul-Henning Kamp</pre> 19095bb6a25fSPoul-Henning Kamp<p>Sets a handler that will be called for all entity declarations. 19105bb6a25fSPoul-Henning KampThe <code>is_parameter_entity</code> argument will be non-zero in the 19115bb6a25fSPoul-Henning Kampcase of parameter entities and zero otherwise.</p> 19125bb6a25fSPoul-Henning Kamp 19135bb6a25fSPoul-Henning Kamp<p>For internal entities (<code><!ENTITY foo "bar"></code>), 19145bb6a25fSPoul-Henning Kamp<code>value</code> will be non-NULL and <code>systemId</code>, 19155bb6a25fSPoul-Henning Kamp<code>publicId</code>, and <code>notationName</code> will all be NULL. 19165bb6a25fSPoul-Henning KampThe value string is <em>not</em> NULL terminated; the length is 19175bb6a25fSPoul-Henning Kampprovided in the <code>value_length</code> parameter. Do not use 19185bb6a25fSPoul-Henning Kamp<code>value_length</code> to test for internal entities, since it is 19195bb6a25fSPoul-Henning Kamplegal to have zero-length values. Instead check for whether or not 19205bb6a25fSPoul-Henning Kamp<code>value</code> is NULL.</p> <p>The <code>notationName</code> 19215bb6a25fSPoul-Henning Kampargument will have a non-NULL value only for unparsed entity 19225bb6a25fSPoul-Henning Kampdeclarations.</p> 19235bb6a25fSPoul-Henning Kamp</div> 19245bb6a25fSPoul-Henning Kamp 19255bb6a25fSPoul-Henning Kamp<div class="handler"> 1926cc68614dSXin LI<h4 id="XML_SetUnparsedEntityDeclHandler">XML_SetUnparsedEntityDeclHandler</h4> 1927cc68614dSXin LI<pre class="setter"> 1928220ed979SColeman Kanevoid XMLCALL 19295bb6a25fSPoul-Henning KampXML_SetUnparsedEntityDeclHandler(XML_Parser p, 19305bb6a25fSPoul-Henning Kamp XML_UnparsedEntityDeclHandler h) 19315bb6a25fSPoul-Henning Kamp</pre> 19325bb6a25fSPoul-Henning Kamp<pre class="signature"> 19335bb6a25fSPoul-Henning Kamptypedef void 1934220ed979SColeman Kane(XMLCALL *XML_UnparsedEntityDeclHandler)(void *userData, 19355bb6a25fSPoul-Henning Kamp const XML_Char *entityName, 19365bb6a25fSPoul-Henning Kamp const XML_Char *base, 19375bb6a25fSPoul-Henning Kamp const XML_Char *systemId, 19385bb6a25fSPoul-Henning Kamp const XML_Char *publicId, 19395bb6a25fSPoul-Henning Kamp const XML_Char *notationName); 19405bb6a25fSPoul-Henning Kamp</pre> 19415bb6a25fSPoul-Henning Kamp<p>Set a handler that receives declarations of unparsed entities. These 19425bb6a25fSPoul-Henning Kampare entity declarations that have a notation (NDATA) field:</p> 19435bb6a25fSPoul-Henning Kamp 19445bb6a25fSPoul-Henning Kamp<div id="eg"><pre> 19455bb6a25fSPoul-Henning Kamp<!ENTITY logo SYSTEM "images/logo.gif" NDATA gif> 19465bb6a25fSPoul-Henning Kamp</pre></div> 19475bb6a25fSPoul-Henning Kamp<p>This handler is obsolete and is provided for backwards 19485bb6a25fSPoul-Henning Kampcompatibility. Use instead <a href= "#XML_SetEntityDeclHandler" 19495bb6a25fSPoul-Henning Kamp>XML_SetEntityDeclHandler</a>.</p> 19505bb6a25fSPoul-Henning Kamp</div> 19515bb6a25fSPoul-Henning Kamp 19525bb6a25fSPoul-Henning Kamp<div class="handler"> 1953cc68614dSXin LI<h4 id="XML_SetNotationDeclHandler">XML_SetNotationDeclHandler</h4> 1954cc68614dSXin LI<pre class="setter"> 1955220ed979SColeman Kanevoid XMLCALL 19565bb6a25fSPoul-Henning KampXML_SetNotationDeclHandler(XML_Parser p, 19575bb6a25fSPoul-Henning Kamp XML_NotationDeclHandler h) 19585bb6a25fSPoul-Henning Kamp</pre> 19595bb6a25fSPoul-Henning Kamp<pre class="signature"> 19605bb6a25fSPoul-Henning Kamptypedef void 1961220ed979SColeman Kane(XMLCALL *XML_NotationDeclHandler)(void *userData, 19625bb6a25fSPoul-Henning Kamp const XML_Char *notationName, 19635bb6a25fSPoul-Henning Kamp const XML_Char *base, 19645bb6a25fSPoul-Henning Kamp const XML_Char *systemId, 19655bb6a25fSPoul-Henning Kamp const XML_Char *publicId); 19665bb6a25fSPoul-Henning Kamp</pre> 19675bb6a25fSPoul-Henning Kamp<p>Set a handler that receives notation declarations.</p> 19685bb6a25fSPoul-Henning Kamp</div> 19695bb6a25fSPoul-Henning Kamp 19705bb6a25fSPoul-Henning Kamp<div class="handler"> 1971cc68614dSXin LI<h4 id="XML_SetNotStandaloneHandler">XML_SetNotStandaloneHandler</h4> 1972cc68614dSXin LI<pre class="setter"> 1973220ed979SColeman Kanevoid XMLCALL 19745bb6a25fSPoul-Henning KampXML_SetNotStandaloneHandler(XML_Parser p, 19755bb6a25fSPoul-Henning Kamp XML_NotStandaloneHandler h) 19765bb6a25fSPoul-Henning Kamp</pre> 19775bb6a25fSPoul-Henning Kamp<pre class="signature"> 19785bb6a25fSPoul-Henning Kamptypedef int 1979220ed979SColeman Kane(XMLCALL *XML_NotStandaloneHandler)(void *userData); 19805bb6a25fSPoul-Henning Kamp</pre> 19815bb6a25fSPoul-Henning Kamp<p>Set a handler that is called if the document is not "standalone". 19825bb6a25fSPoul-Henning KampThis happens when there is an external subset or a reference to a 19835bb6a25fSPoul-Henning Kampparameter entity, but does not have standalone set to "yes" in an XML 1984220ed979SColeman Kanedeclaration. If this handler returns <code>XML_STATUS_ERROR</code>, 1985220ed979SColeman Kanethen the parser will throw an <code>XML_ERROR_NOT_STANDALONE</code> 1986220ed979SColeman Kaneerror.</p> 19875bb6a25fSPoul-Henning Kamp</div> 19885bb6a25fSPoul-Henning Kamp 19895bb6a25fSPoul-Henning Kamp<h3><a name="position">Parse position and error reporting functions</a></h3> 19905bb6a25fSPoul-Henning Kamp 19915bb6a25fSPoul-Henning Kamp<p>These are the functions you'll want to call when the parse 1992220ed979SColeman Kanefunctions return <code>XML_STATUS_ERROR</code> (a parse error has 1993220ed979SColeman Kaneoccurred), although the position reporting functions are useful outside 1994220ed979SColeman Kaneof errors. The position reported is the byte position (in the original 1995220ed979SColeman Kanedocument or entity encoding) of the first of the sequence of 1996220ed979SColeman Kanecharacters that generated the current event (or the error that caused 1997220ed979SColeman Kanethe parse functions to return <code>XML_STATUS_ERROR</code>.) The 1998cc68614dSXin LIexceptions are callbacks triggered by declarations in the document 1999220ed979SColeman Kaneprologue, in which case they exact position reported is somewhere in the 2000220ed979SColeman Kanerelevant markup, but not necessarily as meaningful as for other 2001220ed979SColeman Kaneevents.</p> 20025bb6a25fSPoul-Henning Kamp 20035bb6a25fSPoul-Henning Kamp<p>The position reporting functions are accurate only outside of the 20045bb6a25fSPoul-Henning KampDTD. In other words, they usually return bogus information when 20055bb6a25fSPoul-Henning Kampcalled from within a DTD declaration handler.</p> 20065bb6a25fSPoul-Henning Kamp 2007cc68614dSXin LI<h4 id="XML_GetErrorCode">XML_GetErrorCode</h4> 2008cc68614dSXin LI<pre class="fcndec"> 2009220ed979SColeman Kaneenum XML_Error XMLCALL 20105bb6a25fSPoul-Henning KampXML_GetErrorCode(XML_Parser p); 20115bb6a25fSPoul-Henning Kamp</pre> 20125bb6a25fSPoul-Henning Kamp<div class="fcndef"> 20135bb6a25fSPoul-Henning KampReturn what type of error has occurred. 20145bb6a25fSPoul-Henning Kamp</div> 20155bb6a25fSPoul-Henning Kamp 2016cc68614dSXin LI<h4 id="XML_ErrorString">XML_ErrorString</h4> 2017cc68614dSXin LI<pre class="fcndec"> 2018220ed979SColeman Kaneconst XML_LChar * XMLCALL 2019220ed979SColeman KaneXML_ErrorString(enum XML_Error code); 20205bb6a25fSPoul-Henning Kamp</pre> 20215bb6a25fSPoul-Henning Kamp<div class="fcndef"> 20225bb6a25fSPoul-Henning KampReturn a string describing the error corresponding to code. 20235bb6a25fSPoul-Henning KampThe code should be one of the enums that can be returned from 20245bb6a25fSPoul-Henning Kamp<code><a href= "#XML_GetErrorCode" >XML_GetErrorCode</a></code>. 20255bb6a25fSPoul-Henning Kamp</div> 20265bb6a25fSPoul-Henning Kamp 2027cc68614dSXin LI<h4 id="XML_GetCurrentByteIndex">XML_GetCurrentByteIndex</h4> 2028cc68614dSXin LI<pre class="fcndec"> 2029220ed979SColeman KaneXML_Index XMLCALL 20305bb6a25fSPoul-Henning KampXML_GetCurrentByteIndex(XML_Parser p); 20315bb6a25fSPoul-Henning Kamp</pre> 20325bb6a25fSPoul-Henning Kamp<div class="fcndef"> 2033220ed979SColeman KaneReturn the byte offset of the position. This always corresponds to 2034220ed979SColeman Kanethe values returned by <code><a href= "#XML_GetCurrentLineNumber" 2035220ed979SColeman Kane>XML_GetCurrentLineNumber</a></code> and <code><a href= 2036220ed979SColeman Kane"#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code>. 20375bb6a25fSPoul-Henning Kamp</div> 20385bb6a25fSPoul-Henning Kamp 2039cc68614dSXin LI<h4 id="XML_GetCurrentLineNumber">XML_GetCurrentLineNumber</h4> 2040cc68614dSXin LI<pre class="fcndec"> 2041220ed979SColeman KaneXML_Size XMLCALL 20425bb6a25fSPoul-Henning KampXML_GetCurrentLineNumber(XML_Parser p); 20435bb6a25fSPoul-Henning Kamp</pre> 20445bb6a25fSPoul-Henning Kamp<div class="fcndef"> 2045220ed979SColeman KaneReturn the line number of the position. The first line is reported as 2046220ed979SColeman Kane<code>1</code>. 20475bb6a25fSPoul-Henning Kamp</div> 20485bb6a25fSPoul-Henning Kamp 2049cc68614dSXin LI<h4 id="XML_GetCurrentColumnNumber">XML_GetCurrentColumnNumber</h4> 2050cc68614dSXin LI<pre class="fcndec"> 2051220ed979SColeman KaneXML_Size XMLCALL 20525bb6a25fSPoul-Henning KampXML_GetCurrentColumnNumber(XML_Parser p); 20535bb6a25fSPoul-Henning Kamp</pre> 20545bb6a25fSPoul-Henning Kamp<div class="fcndef"> 20555bb6a25fSPoul-Henning KampReturn the offset, from the beginning of the current line, of 20565bb6a25fSPoul-Henning Kampthe position. 20575bb6a25fSPoul-Henning Kamp</div> 20585bb6a25fSPoul-Henning Kamp 2059cc68614dSXin LI<h4 id="XML_GetCurrentByteCount">XML_GetCurrentByteCount</h4> 2060cc68614dSXin LI<pre class="fcndec"> 2061220ed979SColeman Kaneint XMLCALL 20625bb6a25fSPoul-Henning KampXML_GetCurrentByteCount(XML_Parser p); 20635bb6a25fSPoul-Henning Kamp</pre> 20645bb6a25fSPoul-Henning Kamp<div class="fcndef"> 20655bb6a25fSPoul-Henning KampReturn the number of bytes in the current event. Returns 20665bb6a25fSPoul-Henning Kamp<code>0</code> if the event is inside a reference to an internal 20675bb6a25fSPoul-Henning Kampentity and for the end-tag event for empty element tags (the later can 20685bb6a25fSPoul-Henning Kampbe used to distinguish empty-element tags from empty elements using 20695bb6a25fSPoul-Henning Kampseparate start and end tags). 20705bb6a25fSPoul-Henning Kamp</div> 20715bb6a25fSPoul-Henning Kamp 2072cc68614dSXin LI<h4 id="XML_GetInputContext">XML_GetInputContext</h4> 2073cc68614dSXin LI<pre class="fcndec"> 2074220ed979SColeman Kaneconst char * XMLCALL 20755bb6a25fSPoul-Henning KampXML_GetInputContext(XML_Parser p, 20765bb6a25fSPoul-Henning Kamp int *offset, 20775bb6a25fSPoul-Henning Kamp int *size); 20785bb6a25fSPoul-Henning Kamp</pre> 20795bb6a25fSPoul-Henning Kamp<div class="fcndef"> 20805bb6a25fSPoul-Henning Kamp 20815bb6a25fSPoul-Henning Kamp<p>Returns the parser's input buffer, sets the integer pointed at by 20825bb6a25fSPoul-Henning Kamp<code>offset</code> to the offset within this buffer of the current 20835bb6a25fSPoul-Henning Kampparse position, and set the integer pointed at by <code>size</code> to 20845bb6a25fSPoul-Henning Kampthe size of the returned buffer.</p> 20855bb6a25fSPoul-Henning Kamp 20865bb6a25fSPoul-Henning Kamp<p>This should only be called from within a handler during an active 20875bb6a25fSPoul-Henning Kampparse and the returned buffer should only be referred to from within 20885bb6a25fSPoul-Henning Kampthe handler that made the call. This input buffer contains the 20895bb6a25fSPoul-Henning Kampuntranslated bytes of the input.</p> 20905bb6a25fSPoul-Henning Kamp 20915bb6a25fSPoul-Henning Kamp<p>Only a limited amount of context is kept, so if the event 20925bb6a25fSPoul-Henning Kamptriggering a call spans over a very large amount of input, the actual 20935bb6a25fSPoul-Henning Kampparse position may be before the beginning of the buffer.</p> 2094220ed979SColeman Kane 2095220ed979SColeman Kane<p>If <code>XML_CONTEXT_BYTES</code> is not defined, this will always 2096220ed979SColeman Kanereturn NULL.</p> 20975bb6a25fSPoul-Henning Kamp</div> 20985bb6a25fSPoul-Henning Kamp 2099cc68614dSXin LI<h3><a name="billion-laughs">Billion Laughs Attack Protection</a></h3> 2100cc68614dSXin LI 2101cc68614dSXin LI<p>The functions in this section configure the built-in 2102cc68614dSXin LI protection against various forms of 2103cc68614dSXin LI <a href="https://en.wikipedia.org/wiki/Billion_laughs_attack">billion laughs attacks</a>.</p> 2104cc68614dSXin LI 2105cc68614dSXin LI<h4 id="XML_SetBillionLaughsAttackProtectionMaximumAmplification">XML_SetBillionLaughsAttackProtectionMaximumAmplification</h4> 2106cc68614dSXin LI<pre class="fcndec"> 2107cc68614dSXin LI/* Added in Expat 2.4.0. */ 2108cc68614dSXin LIXML_Bool XMLCALL 2109cc68614dSXin LIXML_SetBillionLaughsAttackProtectionMaximumAmplification(XML_Parser p, 2110cc68614dSXin LI float maximumAmplificationFactor); 2111cc68614dSXin LI</pre> 2112cc68614dSXin LI<div class="fcndef"> 2113cc68614dSXin LI <p> 2114cc68614dSXin LI Sets the maximum tolerated amplification factor 2115cc68614dSXin LI for protection against 2116cc68614dSXin LI <a href="https://en.wikipedia.org/wiki/Billion_laughs_attack">billion laughs attacks</a> 2117cc68614dSXin LI (default: <code>100.0</code>) 2118cc68614dSXin LI of parser <code>p</code> to <code>maximumAmplificationFactor</code>, and 2119cc68614dSXin LI returns <code>XML_TRUE</code> upon success and <code>XML_FALSE</code> upon error. 2120cc68614dSXin LI </p> 2121cc68614dSXin LI 2122cc68614dSXin LI The amplification factor is calculated as .. 2123cc68614dSXin LI <pre> 2124cc68614dSXin LI amplification := (direct + indirect) / direct 2125cc68614dSXin LI </pre> 2126cc68614dSXin LI .. while parsing, whereas 2127cc68614dSXin LI <code>direct</code> is the number of bytes read from the primary document in parsing and 2128cc68614dSXin LI <code>indirect</code> is the number of bytes added by expanding entities and reading of external DTD files, combined. 2129cc68614dSXin LI 2130cc68614dSXin LI <p>For a call to <code>XML_SetBillionLaughsAttackProtectionMaximumAmplification</code> to succeed:</p> 2131cc68614dSXin LI <ul> 2132cc68614dSXin LI <li>parser <code>p</code> must be a non-<code>NULL</code> root parser (without any parent parsers) and</li> 2133cc68614dSXin LI <li><code>maximumAmplificationFactor</code> must be non-<code>NaN</code> and greater than or equal to <code>1.0</code>.</li> 2134cc68614dSXin LI </ul> 2135cc68614dSXin LI 2136cc68614dSXin LI <p> 2137cc68614dSXin LI <strong>Note:</strong> 2138cc68614dSXin LI If you ever need to increase this value for non-attack payload, 2139cc68614dSXin LI please <a href="https://github.com/libexpat/libexpat/issues">file a bug report</a>. 2140cc68614dSXin LI </p> 2141cc68614dSXin LI 2142cc68614dSXin LI <p> 2143cc68614dSXin LI <strong>Note:</strong> 2144cc68614dSXin LI Peak amplifications 2145cc68614dSXin LI of factor 15,000 for the entire payload and 2146cc68614dSXin LI of factor 30,000 in the middle of parsing 2147cc68614dSXin LI have been observed with small benign files in practice. 2148cc68614dSXin LI 2149cc68614dSXin LI So if you do reduce the maximum allowed amplification, 2150cc68614dSXin LI please make sure that the activation threshold is still big enough 2151cc68614dSXin LI to not end up with undesired false positives (i.e. benign files being rejected). 2152cc68614dSXin LI </p> 2153cc68614dSXin LI</div> 2154cc68614dSXin LI 2155cc68614dSXin LI<h4 id="XML_SetBillionLaughsAttackProtectionActivationThreshold">XML_SetBillionLaughsAttackProtectionActivationThreshold</h4> 2156cc68614dSXin LI<pre class="fcndec"> 2157cc68614dSXin LI/* Added in Expat 2.4.0. */ 2158cc68614dSXin LIXML_Bool XMLCALL 2159cc68614dSXin LIXML_SetBillionLaughsAttackProtectionActivationThreshold(XML_Parser p, 2160cc68614dSXin LI unsigned long long activationThresholdBytes); 2161cc68614dSXin LI</pre> 2162cc68614dSXin LI<div class="fcndef"> 2163cc68614dSXin LI <p> 2164cc68614dSXin LI Sets number of output bytes (including amplification from entity expansion and reading DTD files) 2165cc68614dSXin LI needed to activate protection against 2166cc68614dSXin LI <a href="https://en.wikipedia.org/wiki/Billion_laughs_attack">billion laughs attacks</a> 2167cc68614dSXin LI (default: <code>8 MiB</code>) 2168cc68614dSXin LI of parser <code>p</code> to <code>activationThresholdBytes</code>, and 2169cc68614dSXin LI returns <code>XML_TRUE</code> upon success and <code>XML_FALSE</code> upon error. 2170cc68614dSXin LI </p> 2171cc68614dSXin LI 2172cc68614dSXin LI <p>For a call to <code>XML_SetBillionLaughsAttackProtectionActivationThreshold</code> to succeed:</p> 2173cc68614dSXin LI <ul> 2174cc68614dSXin LI <li>parser <code>p</code> must be a non-<code>NULL</code> root parser (without any parent parsers).</li> 2175cc68614dSXin LI </ul> 2176cc68614dSXin LI 2177cc68614dSXin LI <p> 2178cc68614dSXin LI <strong>Note:</strong> 2179cc68614dSXin LI If you ever need to increase this value for non-attack payload, 2180cc68614dSXin LI please <a href="https://github.com/libexpat/libexpat/issues">file a bug report</a>. 2181cc68614dSXin LI </p> 2182cc68614dSXin LI 2183cc68614dSXin LI <p> 2184cc68614dSXin LI <strong>Note:</strong> 2185cc68614dSXin LI Activation thresholds below 4 MiB are known to break support for 2186cc68614dSXin LI <a href="https://en.wikipedia.org/wiki/Darwin_Information_Typing_Architecture">DITA</a> 1.3 payload 2187cc68614dSXin LI and are hence not recommended. 2188cc68614dSXin LI </p> 2189cc68614dSXin LI</div> 2190cc68614dSXin LI 21915bb6a25fSPoul-Henning Kamp<h3><a name="miscellaneous">Miscellaneous functions</a></h3> 21925bb6a25fSPoul-Henning Kamp 21935bb6a25fSPoul-Henning Kamp<p>The functions in this section either obtain state information from 21940a48773fSEric van Gyzenthe parser or can be used to dynamically set parser options.</p> 21955bb6a25fSPoul-Henning Kamp 2196cc68614dSXin LI<h4 id="XML_SetUserData">XML_SetUserData</h4> 2197cc68614dSXin LI<pre class="fcndec"> 2198220ed979SColeman Kanevoid XMLCALL 21995bb6a25fSPoul-Henning KampXML_SetUserData(XML_Parser p, 22005bb6a25fSPoul-Henning Kamp void *userData); 22015bb6a25fSPoul-Henning Kamp</pre> 22025bb6a25fSPoul-Henning Kamp<div class="fcndef"> 22035bb6a25fSPoul-Henning KampThis sets the user data pointer that gets passed to handlers. It 22045bb6a25fSPoul-Henning Kampoverwrites any previous value for this pointer. Note that the 22055bb6a25fSPoul-Henning Kampapplication is responsible for freeing the memory associated with 22065bb6a25fSPoul-Henning Kamp<code>userData</code> when it is finished with the parser. So if you 22075bb6a25fSPoul-Henning Kampcall this when there's already a pointer there, and you haven't freed 22085bb6a25fSPoul-Henning Kampthe memory associated with it, then you've probably just leaked 22095bb6a25fSPoul-Henning Kampmemory. 22105bb6a25fSPoul-Henning Kamp</div> 22115bb6a25fSPoul-Henning Kamp 2212cc68614dSXin LI<h4 id="XML_GetUserData">XML_GetUserData</h4> 2213cc68614dSXin LI<pre class="fcndec"> 2214220ed979SColeman Kanevoid * XMLCALL 22155bb6a25fSPoul-Henning KampXML_GetUserData(XML_Parser p); 22165bb6a25fSPoul-Henning Kamp</pre> 22175bb6a25fSPoul-Henning Kamp<div class="fcndef"> 22185bb6a25fSPoul-Henning KampThis returns the user data pointer that gets passed to handlers. 22195bb6a25fSPoul-Henning KampIt is actually implemented as a macro. 22205bb6a25fSPoul-Henning Kamp</div> 22215bb6a25fSPoul-Henning Kamp 2222cc68614dSXin LI<h4 id="XML_UseParserAsHandlerArg">XML_UseParserAsHandlerArg</h4> 2223cc68614dSXin LI<pre class="fcndec"> 2224220ed979SColeman Kanevoid XMLCALL 22255bb6a25fSPoul-Henning KampXML_UseParserAsHandlerArg(XML_Parser p); 22265bb6a25fSPoul-Henning Kamp</pre> 22275bb6a25fSPoul-Henning Kamp<div class="fcndef"> 2228220ed979SColeman KaneAfter this is called, handlers receive the parser in their 2229220ed979SColeman Kane<code>userData</code> arguments. The user data can still be obtained 2230220ed979SColeman Kaneusing the <code><a href= "#XML_GetUserData" 2231220ed979SColeman Kane>XML_GetUserData</a></code> function. 22325bb6a25fSPoul-Henning Kamp</div> 22335bb6a25fSPoul-Henning Kamp 2234cc68614dSXin LI<h4 id="XML_SetBase">XML_SetBase</h4> 2235cc68614dSXin LI<pre class="fcndec"> 2236220ed979SColeman Kaneenum XML_Status XMLCALL 22375bb6a25fSPoul-Henning KampXML_SetBase(XML_Parser p, 22385bb6a25fSPoul-Henning Kamp const XML_Char *base); 22395bb6a25fSPoul-Henning Kamp</pre> 22405bb6a25fSPoul-Henning Kamp<div class="fcndef"> 22415bb6a25fSPoul-Henning KampSet the base to be used for resolving relative URIs in system 2242220ed979SColeman Kaneidentifiers. The return value is <code>XML_STATUS_ERROR</code> if 2243220ed979SColeman Kanethere's no memory to store base, otherwise it's 2244220ed979SColeman Kane<code>XML_STATUS_OK</code>. 22455bb6a25fSPoul-Henning Kamp</div> 22465bb6a25fSPoul-Henning Kamp 2247cc68614dSXin LI<h4 id="XML_GetBase">XML_GetBase</h4> 2248cc68614dSXin LI<pre class="fcndec"> 2249220ed979SColeman Kaneconst XML_Char * XMLCALL 22505bb6a25fSPoul-Henning KampXML_GetBase(XML_Parser p); 22515bb6a25fSPoul-Henning Kamp</pre> 22525bb6a25fSPoul-Henning Kamp<div class="fcndef"> 22535bb6a25fSPoul-Henning KampReturn the base for resolving relative URIs. 22545bb6a25fSPoul-Henning Kamp</div> 22555bb6a25fSPoul-Henning Kamp 2256cc68614dSXin LI<h4 id="XML_GetSpecifiedAttributeCount">XML_GetSpecifiedAttributeCount</h4> 2257cc68614dSXin LI<pre class="fcndec"> 2258220ed979SColeman Kaneint XMLCALL 22595bb6a25fSPoul-Henning KampXML_GetSpecifiedAttributeCount(XML_Parser p); 22605bb6a25fSPoul-Henning Kamp</pre> 22615bb6a25fSPoul-Henning Kamp<div class="fcndef"> 22625bb6a25fSPoul-Henning KampWhen attributes are reported to the start handler in the atts vector, 22635bb6a25fSPoul-Henning Kampattributes that were explicitly set in the element occur before any 22645bb6a25fSPoul-Henning Kampattributes that receive their value from default information in an 22655bb6a25fSPoul-Henning KampATTLIST declaration. This function returns the number of attributes 22665bb6a25fSPoul-Henning Kampthat were explicitly set times two, thus giving the offset in the 22675bb6a25fSPoul-Henning Kamp<code>atts</code> array passed to the start tag handler of the first 22685bb6a25fSPoul-Henning Kampattribute set due to defaults. It supplies information for the last 22695bb6a25fSPoul-Henning Kampcall to a start handler. If called inside a start handler, then that 22705bb6a25fSPoul-Henning Kampmeans the current call. 22715bb6a25fSPoul-Henning Kamp</div> 22725bb6a25fSPoul-Henning Kamp 2273cc68614dSXin LI<h4 id="XML_GetIdAttributeIndex">XML_GetIdAttributeIndex</h4> 2274cc68614dSXin LI<pre class="fcndec"> 2275220ed979SColeman Kaneint XMLCALL 22765bb6a25fSPoul-Henning KampXML_GetIdAttributeIndex(XML_Parser p); 22775bb6a25fSPoul-Henning Kamp</pre> 22785bb6a25fSPoul-Henning Kamp<div class="fcndef"> 22795bb6a25fSPoul-Henning KampReturns the index of the ID attribute passed in the atts array in the 22805bb6a25fSPoul-Henning Kamplast call to <code><a href= "#XML_StartElementHandler" 22815bb6a25fSPoul-Henning Kamp>XML_StartElementHandler</a></code>, or -1 if there is no ID 22825bb6a25fSPoul-Henning Kampattribute. If called inside a start handler, then that means the 22835bb6a25fSPoul-Henning Kampcurrent call. 22845bb6a25fSPoul-Henning Kamp</div> 22855bb6a25fSPoul-Henning Kamp 2286cc68614dSXin LI<h4 id="XML_GetAttributeInfo">XML_GetAttributeInfo</h4> 2287cc68614dSXin LI<pre class="fcndec"> 2288e3466a89SXin LIconst XML_AttrInfo * XMLCALL 2289e3466a89SXin LIXML_GetAttributeInfo(XML_Parser parser); 2290e3466a89SXin LI</pre> 2291e3466a89SXin LI<pre class="signature"> 2292e3466a89SXin LItypedef struct { 2293e3466a89SXin LI XML_Index nameStart; /* Offset to beginning of the attribute name. */ 2294e3466a89SXin LI XML_Index nameEnd; /* Offset after the attribute name's last byte. */ 2295e3466a89SXin LI XML_Index valueStart; /* Offset to beginning of the attribute value. */ 2296e3466a89SXin LI XML_Index valueEnd; /* Offset after the attribute value's last byte. */ 2297e3466a89SXin LI} XML_AttrInfo; 2298e3466a89SXin LI</pre> 2299e3466a89SXin LI<div class="fcndef"> 2300e3466a89SXin LIReturns an array of <code>XML_AttrInfo</code> structures for the 2301e3466a89SXin LIattribute/value pairs passed in the last call to the 2302e3466a89SXin LI<code>XML_StartElementHandler</code> that were specified 2303e3466a89SXin LIin the start-tag rather than defaulted. Each attribute/value pair counts 2304e3466a89SXin LIas 1; thus the number of entries in the array is 2305e3466a89SXin LI<code>XML_GetSpecifiedAttributeCount(parser) / 2</code>. 2306e3466a89SXin LI</div> 2307e3466a89SXin LI 2308cc68614dSXin LI<h4 id="XML_SetEncoding">XML_SetEncoding</h4> 2309cc68614dSXin LI<pre class="fcndec"> 2310220ed979SColeman Kaneenum XML_Status XMLCALL 23115bb6a25fSPoul-Henning KampXML_SetEncoding(XML_Parser p, 23125bb6a25fSPoul-Henning Kamp const XML_Char *encoding); 23135bb6a25fSPoul-Henning Kamp</pre> 23145bb6a25fSPoul-Henning Kamp<div class="fcndef"> 23155bb6a25fSPoul-Henning KampSet the encoding to be used by the parser. It is equivalent to 23165bb6a25fSPoul-Henning Kamppassing a non-null encoding argument to the parser creation functions. 23175bb6a25fSPoul-Henning KampIt must not be called after <code><a href= "#XML_Parse" 23185bb6a25fSPoul-Henning Kamp>XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer" 23195bb6a25fSPoul-Henning Kamp>XML_ParseBuffer</a></code> have been called on the given parser. 2320220ed979SColeman KaneReturns <code>XML_STATUS_OK</code> on success or 2321220ed979SColeman Kane<code>XML_STATUS_ERROR</code> on error. 23225bb6a25fSPoul-Henning Kamp</div> 23235bb6a25fSPoul-Henning Kamp 2324cc68614dSXin LI<h4 id="XML_SetParamEntityParsing">XML_SetParamEntityParsing</h4> 2325cc68614dSXin LI<pre class="fcndec"> 2326220ed979SColeman Kaneint XMLCALL 23275bb6a25fSPoul-Henning KampXML_SetParamEntityParsing(XML_Parser p, 23285bb6a25fSPoul-Henning Kamp enum XML_ParamEntityParsing code); 23295bb6a25fSPoul-Henning Kamp</pre> 23305bb6a25fSPoul-Henning Kamp<div class="fcndef"> 23315bb6a25fSPoul-Henning KampThis enables parsing of parameter entities, including the external 23325bb6a25fSPoul-Henning Kampparameter entity that is the external DTD subset, according to 23335bb6a25fSPoul-Henning Kamp<code>code</code>. 23345bb6a25fSPoul-Henning KampThe choices for <code>code</code> are: 23355bb6a25fSPoul-Henning Kamp<ul> 23365bb6a25fSPoul-Henning Kamp<li><code>XML_PARAM_ENTITY_PARSING_NEVER</code></li> 23375bb6a25fSPoul-Henning Kamp<li><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></li> 23385bb6a25fSPoul-Henning Kamp<li><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></li> 23395bb6a25fSPoul-Henning Kamp</ul> 2340e3466a89SXin LI<b>Note:</b> If <code>XML_SetParamEntityParsing</code> is called after 2341e3466a89SXin LI<code>XML_Parse</code> or <code>XML_ParseBuffer</code>, then it has 2342e3466a89SXin LIno effect and will always return 0. 2343e3466a89SXin LI</div> 2344e3466a89SXin LI 2345cc68614dSXin LI<h4 id="XML_SetHashSalt">XML_SetHashSalt</h4> 2346cc68614dSXin LI<pre class="fcndec"> 2347e3466a89SXin LIint XMLCALL 2348e3466a89SXin LIXML_SetHashSalt(XML_Parser p, 2349e3466a89SXin LI unsigned long hash_salt); 2350e3466a89SXin LI</pre> 2351e3466a89SXin LI<div class="fcndef"> 2352e3466a89SXin LISets the hash salt to use for internal hash calculations. 2353e3466a89SXin LIHelps in preventing DoS attacks based on predicting hash 2354e3466a89SXin LIfunction behavior. In order to have an effect this must be called 2355e3466a89SXin LIbefore parsing has started. Returns 1 if successful, 0 when called 2356e3466a89SXin LIafter <code>XML_Parse</code> or <code>XML_ParseBuffer</code>. 2357be8aff81SXin LI<p><b>Note:</b> This call is optional, as the parser will auto-generate 23586b2c1e49SXin LIa new random salt value if no value has been set at the start of parsing.</p> 2359be8aff81SXin LI<p><b>Note:</b> One should not call <code>XML_SetHashSalt</code> with a 2360be8aff81SXin LIhash salt value of 0, as this value is used as sentinel value to indicate 2361be8aff81SXin LIthat <code>XML_SetHashSalt</code> has <b>not</b> been called. Consequently 2362be8aff81SXin LIsuch a call will have no effect, even if it returns 1.</p> 23635bb6a25fSPoul-Henning Kamp</div> 23645bb6a25fSPoul-Henning Kamp 2365cc68614dSXin LI<h4 id="XML_UseForeignDTD">XML_UseForeignDTD</h4> 2366cc68614dSXin LI<pre class="fcndec"> 2367220ed979SColeman Kaneenum XML_Error XMLCALL 23685bb6a25fSPoul-Henning KampXML_UseForeignDTD(XML_Parser parser, XML_Bool useDTD); 23695bb6a25fSPoul-Henning Kamp</pre> 23705bb6a25fSPoul-Henning Kamp<div class="fcndef"> 23715bb6a25fSPoul-Henning Kamp<p>This function allows an application to provide an external subset 23725bb6a25fSPoul-Henning Kampfor the document type declaration for documents which do not specify 23735bb6a25fSPoul-Henning Kampan external subset of their own. For documents which specify an 23745bb6a25fSPoul-Henning Kampexternal subset in their DOCTYPE declaration, the application-provided 23755bb6a25fSPoul-Henning Kampsubset will be ignored. If the document does not contain a DOCTYPE 23765bb6a25fSPoul-Henning Kampdeclaration at all and <code>useDTD</code> is true, the 23775bb6a25fSPoul-Henning Kampapplication-provided subset will be parsed, but the 23785bb6a25fSPoul-Henning Kamp<code>startDoctypeDeclHandler</code> and 23795bb6a25fSPoul-Henning Kamp<code>endDoctypeDeclHandler</code> functions, if set, will not be 23805bb6a25fSPoul-Henning Kampcalled. The setting of parameter entity parsing, controlled using 23815bb6a25fSPoul-Henning Kamp<code><a href= "#XML_SetParamEntityParsing" 23825bb6a25fSPoul-Henning Kamp>XML_SetParamEntityParsing</a></code>, will be honored.</p> 23835bb6a25fSPoul-Henning Kamp 23845bb6a25fSPoul-Henning Kamp<p>The application-provided external subset is read by calling the 23855bb6a25fSPoul-Henning Kampexternal entity reference handler set via <code><a href= 23865bb6a25fSPoul-Henning Kamp"#XML_SetExternalEntityRefHandler" 23875bb6a25fSPoul-Henning Kamp>XML_SetExternalEntityRefHandler</a></code> with both 23885bb6a25fSPoul-Henning Kamp<code>publicId</code> and <code>systemId</code> set to NULL.</p> 23895bb6a25fSPoul-Henning Kamp 23905bb6a25fSPoul-Henning Kamp<p>If this function is called after parsing has begun, it returns 23915bb6a25fSPoul-Henning Kamp<code>XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING</code> and ignores 23925bb6a25fSPoul-Henning Kamp<code>useDTD</code>. If called when Expat has been compiled without 23935bb6a25fSPoul-Henning KampDTD support, it returns 23945bb6a25fSPoul-Henning Kamp<code>XML_ERROR_FEATURE_REQUIRES_XML_DTD</code>. Otherwise, it 23955bb6a25fSPoul-Henning Kampreturns <code>XML_ERROR_NONE</code>.</p> 2396220ed979SColeman Kane 2397220ed979SColeman Kane<p><b>Note:</b> For the purpose of checking WFC: Entity Declared, passing 2398220ed979SColeman Kane<code>useDTD == XML_TRUE</code> will make the parser behave as if 2399220ed979SColeman Kanethe document had a DTD with an external subset. This holds true even if 2400220ed979SColeman Kanethe external entity reference handler returns without action.</p> 24015bb6a25fSPoul-Henning Kamp</div> 24025bb6a25fSPoul-Henning Kamp 2403cc68614dSXin LI<h4 id="XML_SetReturnNSTriplet">XML_SetReturnNSTriplet</h4> 2404cc68614dSXin LI<pre class="fcndec"> 2405220ed979SColeman Kanevoid XMLCALL 24065bb6a25fSPoul-Henning KampXML_SetReturnNSTriplet(XML_Parser parser, 24075bb6a25fSPoul-Henning Kamp int do_nst); 24085bb6a25fSPoul-Henning Kamp</pre> 24095bb6a25fSPoul-Henning Kamp<div class="fcndef"> 24105bb6a25fSPoul-Henning Kamp<p> 24115bb6a25fSPoul-Henning KampThis function only has an effect when using a parser created with 24125bb6a25fSPoul-Henning Kamp<code><a href= "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>, 24135bb6a25fSPoul-Henning Kampi.e. when namespace processing is in effect. The <code>do_nst</code> 24145bb6a25fSPoul-Henning Kampsets whether or not prefixes are returned with names qualified with a 24155bb6a25fSPoul-Henning Kampnamespace prefix. If this function is called with <code>do_nst</code> 24165bb6a25fSPoul-Henning Kampnon-zero, then afterwards namespace qualified names (that is qualified 24175bb6a25fSPoul-Henning Kampwith a prefix as opposed to belonging to a default namespace) are 24185bb6a25fSPoul-Henning Kampreturned as a triplet with the three parts separated by the namespace 24195bb6a25fSPoul-Henning Kampseparator specified when the parser was created. The order of 24205bb6a25fSPoul-Henning Kampreturned parts is URI, local name, and prefix.</p> <p>If 24215bb6a25fSPoul-Henning Kamp<code>do_nst</code> is zero, then namespaces are reported in the 24225bb6a25fSPoul-Henning Kampdefault manner, URI then local_name separated by the namespace 24235bb6a25fSPoul-Henning Kampseparator.</p> 24245bb6a25fSPoul-Henning Kamp</div> 24255bb6a25fSPoul-Henning Kamp 2426cc68614dSXin LI<h4 id="XML_DefaultCurrent">XML_DefaultCurrent</h4> 2427cc68614dSXin LI<pre class="fcndec"> 2428220ed979SColeman Kanevoid XMLCALL 24295bb6a25fSPoul-Henning KampXML_DefaultCurrent(XML_Parser parser); 24305bb6a25fSPoul-Henning Kamp</pre> 24315bb6a25fSPoul-Henning Kamp<div class="fcndef"> 24325bb6a25fSPoul-Henning KampThis can be called within a handler for a start element, end element, 24335bb6a25fSPoul-Henning Kampprocessing instruction or character data. It causes the corresponding 24345bb6a25fSPoul-Henning Kampmarkup to be passed to the default handler set by <code><a 24355bb6a25fSPoul-Henning Kamphref="#XML_SetDefaultHandler" >XML_SetDefaultHandler</a></code> or 24365bb6a25fSPoul-Henning Kamp<code><a href="#XML_SetDefaultHandlerExpand" 24375bb6a25fSPoul-Henning Kamp>XML_SetDefaultHandlerExpand</a></code>. It does nothing if there is 24385bb6a25fSPoul-Henning Kampnot a default handler. 24395bb6a25fSPoul-Henning Kamp</div> 24405bb6a25fSPoul-Henning Kamp 2441cc68614dSXin LI<h4 id="XML_ExpatVersion">XML_ExpatVersion</h4> 2442cc68614dSXin LI<pre class="fcndec"> 2443220ed979SColeman KaneXML_LChar * XMLCALL 24445bb6a25fSPoul-Henning KampXML_ExpatVersion(); 24455bb6a25fSPoul-Henning Kamp</pre> 24465bb6a25fSPoul-Henning Kamp<div class="fcndef"> 24475bb6a25fSPoul-Henning KampReturn the library version as a string (e.g. <code>"expat_1.95.1"</code>). 24485bb6a25fSPoul-Henning Kamp</div> 24495bb6a25fSPoul-Henning Kamp 2450cc68614dSXin LI<h4 id="XML_ExpatVersionInfo">XML_ExpatVersionInfo</h4> 2451cc68614dSXin LI<pre class="fcndec"> 2452220ed979SColeman Kanestruct XML_Expat_Version XMLCALL 24535bb6a25fSPoul-Henning KampXML_ExpatVersionInfo(); 24545bb6a25fSPoul-Henning Kamp</pre> 24555bb6a25fSPoul-Henning Kamp<pre class="signature"> 24565bb6a25fSPoul-Henning Kamptypedef struct { 24575bb6a25fSPoul-Henning Kamp int major; 24585bb6a25fSPoul-Henning Kamp int minor; 24595bb6a25fSPoul-Henning Kamp int micro; 24605bb6a25fSPoul-Henning Kamp} XML_Expat_Version; 24615bb6a25fSPoul-Henning Kamp</pre> 24625bb6a25fSPoul-Henning Kamp<div class="fcndef"> 24635bb6a25fSPoul-Henning KampReturn the library version information as a structure. 24645bb6a25fSPoul-Henning KampSome macros are also defined that support compile-time tests of the 24655bb6a25fSPoul-Henning Kamplibrary version: 24665bb6a25fSPoul-Henning Kamp<ul> 24675bb6a25fSPoul-Henning Kamp<li><code>XML_MAJOR_VERSION</code></li> 24685bb6a25fSPoul-Henning Kamp<li><code>XML_MINOR_VERSION</code></li> 24695bb6a25fSPoul-Henning Kamp<li><code>XML_MICRO_VERSION</code></li> 24705bb6a25fSPoul-Henning Kamp</ul> 24715bb6a25fSPoul-Henning KampTesting these constants is currently the best way to determine if 24725bb6a25fSPoul-Henning Kampparticular parts of the Expat API are available. 24735bb6a25fSPoul-Henning Kamp</div> 24745bb6a25fSPoul-Henning Kamp 2475cc68614dSXin LI<h4 id="XML_GetFeatureList">XML_GetFeatureList</h4> 2476cc68614dSXin LI<pre class="fcndec"> 2477220ed979SColeman Kaneconst XML_Feature * XMLCALL 24785bb6a25fSPoul-Henning KampXML_GetFeatureList(); 24795bb6a25fSPoul-Henning Kamp</pre> 24805bb6a25fSPoul-Henning Kamp<pre class="signature"> 24815bb6a25fSPoul-Henning Kampenum XML_FeatureEnum { 24825bb6a25fSPoul-Henning Kamp XML_FEATURE_END = 0, 24835bb6a25fSPoul-Henning Kamp XML_FEATURE_UNICODE, 24845bb6a25fSPoul-Henning Kamp XML_FEATURE_UNICODE_WCHAR_T, 24855bb6a25fSPoul-Henning Kamp XML_FEATURE_DTD, 24865bb6a25fSPoul-Henning Kamp XML_FEATURE_CONTEXT_BYTES, 24875bb6a25fSPoul-Henning Kamp XML_FEATURE_MIN_SIZE, 24885bb6a25fSPoul-Henning Kamp XML_FEATURE_SIZEOF_XML_CHAR, 2489220ed979SColeman Kane XML_FEATURE_SIZEOF_XML_LCHAR, 2490220ed979SColeman Kane XML_FEATURE_NS, 2491220ed979SColeman Kane XML_FEATURE_LARGE_SIZE 24925bb6a25fSPoul-Henning Kamp}; 24935bb6a25fSPoul-Henning Kamp 24945bb6a25fSPoul-Henning Kamptypedef struct { 24955bb6a25fSPoul-Henning Kamp enum XML_FeatureEnum feature; 24965bb6a25fSPoul-Henning Kamp XML_LChar *name; 24975bb6a25fSPoul-Henning Kamp long int value; 24985bb6a25fSPoul-Henning Kamp} XML_Feature; 24995bb6a25fSPoul-Henning Kamp</pre> 25005bb6a25fSPoul-Henning Kamp<div class="fcndef"> 25015bb6a25fSPoul-Henning Kamp<p>Returns a list of "feature" records, providing details on how 25025bb6a25fSPoul-Henning KampExpat was configured at compile time. Most applications should not 25035bb6a25fSPoul-Henning Kampneed to worry about this, but this information is otherwise not 25045bb6a25fSPoul-Henning Kampavailable from Expat. This function allows code that does need to 25055bb6a25fSPoul-Henning Kampcheck these features to do so at runtime.</p> 25065bb6a25fSPoul-Henning Kamp 25075bb6a25fSPoul-Henning Kamp<p>The return value is an array of <code>XML_Feature</code>, 25085bb6a25fSPoul-Henning Kampterminated by a record with a <code>feature</code> of 25095bb6a25fSPoul-Henning Kamp<code>XML_FEATURE_END</code> and <code>name</code> of NULL, 25105bb6a25fSPoul-Henning Kampidentifying the feature-test macros Expat was compiled with. Since an 25115bb6a25fSPoul-Henning Kampapplication that requires this kind of information needs to determine 25125bb6a25fSPoul-Henning Kampthe type of character the <code>name</code> points to, records for the 25135bb6a25fSPoul-Henning Kamp<code>XML_FEATURE_SIZEOF_XML_CHAR</code> and 25145bb6a25fSPoul-Henning Kamp<code>XML_FEATURE_SIZEOF_XML_LCHAR</code> will be located at the 25155bb6a25fSPoul-Henning Kampbeginning of the list, followed by <code>XML_FEATURE_UNICODE</code> 25165bb6a25fSPoul-Henning Kampand <code>XML_FEATURE_UNICODE_WCHAR_T</code>, if they are present at 25175bb6a25fSPoul-Henning Kampall.</p> 25185bb6a25fSPoul-Henning Kamp 25195bb6a25fSPoul-Henning Kamp<p>Some features have an associated value. If there isn't an 25205bb6a25fSPoul-Henning Kampassociated value, the <code>value</code> field is set to 0. At this 25215bb6a25fSPoul-Henning Kamptime, the following features have been defined to have values:</p> 25225bb6a25fSPoul-Henning Kamp 25235bb6a25fSPoul-Henning Kamp<dl> 25245bb6a25fSPoul-Henning Kamp <dt><code>XML_FEATURE_SIZEOF_XML_CHAR</code></dt> 25255bb6a25fSPoul-Henning Kamp <dd>The number of bytes occupied by one <code>XML_Char</code> 25265bb6a25fSPoul-Henning Kamp character.</dd> 25275bb6a25fSPoul-Henning Kamp <dt><code>XML_FEATURE_SIZEOF_XML_LCHAR</code></dt> 25285bb6a25fSPoul-Henning Kamp <dd>The number of bytes occupied by one <code>XML_LChar</code> 25295bb6a25fSPoul-Henning Kamp character.</dd> 25305bb6a25fSPoul-Henning Kamp <dt><code>XML_FEATURE_CONTEXT_BYTES</code></dt> 25315bb6a25fSPoul-Henning Kamp <dd>The maximum number of characters of context which can be 25325bb6a25fSPoul-Henning Kamp reported by <code><a href= "#XML_GetInputContext" 25335bb6a25fSPoul-Henning Kamp >XML_GetInputContext</a></code>.</dd> 25345bb6a25fSPoul-Henning Kamp</dl> 25355bb6a25fSPoul-Henning Kamp</div> 25365bb6a25fSPoul-Henning Kamp 2537cc68614dSXin LI<h4 id="XML_FreeContentModel">XML_FreeContentModel</h4> 2538cc68614dSXin LI<pre class="fcndec"> 2539220ed979SColeman Kanevoid XMLCALL 2540220ed979SColeman KaneXML_FreeContentModel(XML_Parser parser, XML_Content *model); 2541220ed979SColeman Kane</pre> 2542220ed979SColeman Kane<div class="fcndef"> 2543220ed979SColeman KaneFunction to deallocate the <code>model</code> argument passed to the 2544220ed979SColeman Kane<code>XML_ElementDeclHandler</code> callback set using <code><a 2545220ed979SColeman Kanehref="#XML_SetElementDeclHandler" >XML_ElementDeclHandler</a></code>. 2546220ed979SColeman KaneThis function should not be used for any other purpose. 2547220ed979SColeman Kane</div> 2548220ed979SColeman Kane 2549220ed979SColeman Kane<p>The following functions allow external code to share the memory 2550220ed979SColeman Kaneallocator an <code>XML_Parser</code> has been configured to use. This 2551220ed979SColeman Kaneis especially useful for third-party libraries that interact with a 2552220ed979SColeman Kaneparser object created by application code, or heavily layered 2553220ed979SColeman Kaneapplications. This can be essential when using dynamically loaded 2554220ed979SColeman Kanelibraries which use different C standard libraries (this can happen on 2555220ed979SColeman KaneWindows, at least).</p> 2556220ed979SColeman Kane 2557cc68614dSXin LI<h4 id="XML_MemMalloc">XML_MemMalloc</h4> 2558cc68614dSXin LI<pre class="fcndec"> 2559220ed979SColeman Kanevoid * XMLCALL 2560220ed979SColeman KaneXML_MemMalloc(XML_Parser parser, size_t size); 2561220ed979SColeman Kane</pre> 2562220ed979SColeman Kane<div class="fcndef"> 2563220ed979SColeman KaneAllocate <code>size</code> bytes of memory using the allocator the 2564220ed979SColeman Kane<code>parser</code> object has been configured to use. Returns a 2565220ed979SColeman Kanepointer to the memory or NULL on failure. Memory allocated in this 2566220ed979SColeman Kaneway must be freed using <code><a href="#XML_MemFree" 2567220ed979SColeman Kane>XML_MemFree</a></code>. 2568220ed979SColeman Kane</div> 2569220ed979SColeman Kane 2570cc68614dSXin LI<h4 id="XML_MemRealloc">XML_MemRealloc</h4> 2571cc68614dSXin LI<pre class="fcndec"> 2572220ed979SColeman Kanevoid * XMLCALL 2573220ed979SColeman KaneXML_MemRealloc(XML_Parser parser, void *ptr, size_t size); 2574220ed979SColeman Kane</pre> 2575220ed979SColeman Kane<div class="fcndef"> 2576220ed979SColeman KaneAllocate <code>size</code> bytes of memory using the allocator the 2577220ed979SColeman Kane<code>parser</code> object has been configured to use. 2578220ed979SColeman Kane<code>ptr</code> must point to a block of memory allocated by <code><a 2579220ed979SColeman Kanehref="#XML_MemMalloc" >XML_MemMalloc</a></code> or 2580220ed979SColeman Kane<code>XML_MemRealloc</code>, or be NULL. This function tries to 2581220ed979SColeman Kaneexpand the block pointed to by <code>ptr</code> if possible. Returns 2582220ed979SColeman Kanea pointer to the memory or NULL on failure. On success, the original 2583220ed979SColeman Kaneblock has either been expanded or freed. On failure, the original 2584220ed979SColeman Kaneblock has not been freed; the caller is responsible for freeing the 2585220ed979SColeman Kaneoriginal block. Memory allocated in this way must be freed using 2586220ed979SColeman Kane<code><a href="#XML_MemFree" 2587220ed979SColeman Kane>XML_MemFree</a></code>. 2588220ed979SColeman Kane</div> 2589220ed979SColeman Kane 2590cc68614dSXin LI<h4 id="XML_MemFree">XML_MemFree</h4> 2591cc68614dSXin LI<pre class="fcndec"> 2592220ed979SColeman Kanevoid XMLCALL 2593220ed979SColeman KaneXML_MemFree(XML_Parser parser, void *ptr); 2594220ed979SColeman Kane</pre> 2595220ed979SColeman Kane<div class="fcndef"> 2596220ed979SColeman KaneFree a block of memory pointed to by <code>ptr</code>. The block must 2597220ed979SColeman Kanehave been allocated by <code><a href="#XML_MemMalloc" 2598220ed979SColeman Kane>XML_MemMalloc</a></code> or <code>XML_MemRealloc</code>, or be NULL. 2599220ed979SColeman Kane</div> 2600220ed979SColeman Kane 26015bb6a25fSPoul-Henning Kamp<hr /> 2602cc68614dSXin LI 2603cc68614dSXin LI <div class="footer"> 2604cc68614dSXin LI Found a bug in the documentation? 2605cc68614dSXin LI <a href="https://github.com/libexpat/libexpat/issues">Please file a bug report.</a> 2606cc68614dSXin LI </div> 2607cc68614dSXin LI 2608220ed979SColeman Kane</div> 26095bb6a25fSPoul-Henning Kamp</body> 26105bb6a25fSPoul-Henning Kamp</html> 2611
