reference.html revision 1.1.1.6.4.1
1 1.1 tron <?xml version="1.0" encoding="iso-8859-1"?> 2 1.1 tron <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 3 1.1 tron "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 4 1.1 tron <html> 5 1.1 tron <head> 6 1.1.1.6 christos <!-- 7 1.1.1.6 christos __ __ _ 8 1.1.1.6 christos ___\ \/ /_ __ __ _| |_ 9 1.1.1.6 christos / _ \\ /| '_ \ / _` | __| 10 1.1.1.6 christos | __// \| |_) | (_| | |_ 11 1.1.1.6 christos \___/_/\_\ .__/ \__,_|\__| 12 1.1.1.6 christos |_| XML parser 13 1.1.1.6 christos 14 1.1.1.6 christos Copyright (c) 2000 Clark Cooper <coopercc (a] users.sourceforge.net> 15 1.1.1.6 christos Copyright (c) 2000-2004 Fred L. Drake, Jr. <fdrake (a] users.sourceforge.net> 16 1.1.1.6 christos Copyright (c) 2002-2012 Karl Waclawek <karl (a] waclawek.net> 17 1.1.1.6.4.1 perseant Copyright (c) 2017-2025 Sebastian Pipping <sebastian (a] pipping.org> 18 1.1.1.6 christos Copyright (c) 2017 Jakub Wilk <jwilk (a] jwilk.net> 19 1.1.1.6 christos Copyright (c) 2021 Tomas Korbar <tkorbar (a] redhat.com> 20 1.1.1.6 christos Copyright (c) 2021 Nicolas Cavallari <nicolas.cavallari (a] green-communications.fr> 21 1.1.1.6.4.1 perseant Copyright (c) 2022 Thijs Schreijer <thijs (a] thijsschreijer.nl> 22 1.1.1.6.4.1 perseant Copyright (c) 2023 Hanno Bck <hanno (a] gentoo.org> 23 1.1.1.6.4.1 perseant Copyright (c) 2023 Sony Corporation / Snild Dolkow <snild (a] sony.com> 24 1.1.1.6 christos Licensed under the MIT license: 25 1.1.1.6 christos 26 1.1.1.6 christos Permission is hereby granted, free of charge, to any person obtaining 27 1.1.1.6 christos a copy of this software and associated documentation files (the 28 1.1.1.6 christos "Software"), to deal in the Software without restriction, including 29 1.1.1.6 christos without limitation the rights to use, copy, modify, merge, publish, 30 1.1.1.6 christos distribute, sublicense, and/or sell copies of the Software, and to permit 31 1.1.1.6 christos persons to whom the Software is furnished to do so, subject to the 32 1.1.1.6 christos following conditions: 33 1.1.1.6 christos 34 1.1.1.6 christos The above copyright notice and this permission notice shall be included 35 1.1.1.6 christos in all copies or substantial portions of the Software. 36 1.1.1.6 christos 37 1.1.1.6 christos THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 38 1.1.1.6 christos EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 39 1.1.1.6 christos MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN 40 1.1.1.6 christos NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 41 1.1.1.6 christos DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 42 1.1.1.6 christos OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 43 1.1.1.6 christos USE OR OTHER DEALINGS IN THE SOFTWARE. 44 1.1.1.6 christos --> 45 1.1 tron <title>Expat XML Parser</title> 46 1.1 tron <meta name="author" content="Clark Cooper, coopercc (a] netheaven.com" /> 47 1.1 tron <meta http-equiv="Content-Style-Type" content="text/css" /> 48 1.1.1.6 christos <link href="ok.min.css" rel="stylesheet" type="text/css" /> 49 1.1 tron <link href="style.css" rel="stylesheet" type="text/css" /> 50 1.1 tron </head> 51 1.1 tron <body> 52 1.1.1.6 christos <div> 53 1.1.1.6 christos <h1> 54 1.1.1.6 christos The Expat XML Parser 55 1.1.1.6.4.1 perseant <small>Release 2.7.1</small> 56 1.1.1.6 christos </h1> 57 1.1.1.6 christos </div> 58 1.1 tron <div class="content"> 59 1.1 tron 60 1.1 tron <p>Expat is a library, written in C, for parsing XML documents. It's 61 1.1 tron the underlying XML parser for the open source Mozilla project, Perl's 62 1.1 tron <code>XML::Parser</code>, Python's <code>xml.parsers.expat</code>, and 63 1.1 tron other open-source XML parsers.</p> 64 1.1 tron 65 1.1 tron <p>This library is the creation of James Clark, who's also given us 66 1.1.1.5 maya groff (an nroff look-alike), Jade (an implementation of ISO's DSSSL 67 1.1 tron stylesheet language for SGML), XP (a Java XML parser package), XT (a 68 1.1 tron Java XSL engine). James was also the technical lead on the XML 69 1.1 tron Working Group at W3C that produced the XML specification.</p> 70 1.1 tron 71 1.1 tron <p>This is free software, licensed under the <a 72 1.1 tron href="../COPYING">MIT/X Consortium license</a>. You may download it 73 1.1.1.6.4.1 perseant from <a href="https://libexpat.github.io/">the Expat home page</a>. 74 1.1 tron </p> 75 1.1 tron 76 1.1 tron <p>The bulk of this document was originally commissioned as an article 77 1.1.1.6.4.1 perseant by <a href="https://www.xml.com/">XML.com</a>. They graciously allowed 78 1.1 tron Clark Cooper to retain copyright and to distribute it with Expat. 79 1.1 tron This version has been substantially extended to include documentation 80 1.1 tron on features which have been added since the original article was 81 1.1 tron published, and additional information on using the original 82 1.1 tron interface.</p> 83 1.1 tron 84 1.1 tron <hr /> 85 1.1 tron <h2>Table of Contents</h2> 86 1.1 tron <ul> 87 1.1 tron <li><a href="#overview">Overview</a></li> 88 1.1 tron <li><a href="#building">Building and Installing</a></li> 89 1.1 tron <li><a href="#using">Using Expat</a></li> 90 1.1 tron <li><a href="#reference">Reference</a> 91 1.1 tron <ul> 92 1.1 tron <li><a href="#creation">Parser Creation Functions</a> 93 1.1 tron <ul> 94 1.1 tron <li><a href="#XML_ParserCreate">XML_ParserCreate</a></li> 95 1.1 tron <li><a href="#XML_ParserCreateNS">XML_ParserCreateNS</a></li> 96 1.1 tron <li><a href="#XML_ParserCreate_MM">XML_ParserCreate_MM</a></li> 97 1.1 tron <li><a href="#XML_ExternalEntityParserCreate">XML_ExternalEntityParserCreate</a></li> 98 1.1 tron <li><a href="#XML_ParserFree">XML_ParserFree</a></li> 99 1.1 tron <li><a href="#XML_ParserReset">XML_ParserReset</a></li> 100 1.1 tron </ul> 101 1.1 tron </li> 102 1.1 tron <li><a href="#parsing">Parsing Functions</a> 103 1.1 tron <ul> 104 1.1 tron <li><a href="#XML_Parse">XML_Parse</a></li> 105 1.1 tron <li><a href="#XML_ParseBuffer">XML_ParseBuffer</a></li> 106 1.1 tron <li><a href="#XML_GetBuffer">XML_GetBuffer</a></li> 107 1.1 tron <li><a href="#XML_StopParser">XML_StopParser</a></li> 108 1.1 tron <li><a href="#XML_ResumeParser">XML_ResumeParser</a></li> 109 1.1 tron <li><a href="#XML_GetParsingStatus">XML_GetParsingStatus</a></li> 110 1.1 tron </ul> 111 1.1 tron </li> 112 1.1 tron <li><a href="#setting">Handler Setting Functions</a> 113 1.1 tron <ul> 114 1.1 tron <li><a href="#XML_SetStartElementHandler">XML_SetStartElementHandler</a></li> 115 1.1 tron <li><a href="#XML_SetEndElementHandler">XML_SetEndElementHandler</a></li> 116 1.1 tron <li><a href="#XML_SetElementHandler">XML_SetElementHandler</a></li> 117 1.1 tron <li><a href="#XML_SetCharacterDataHandler">XML_SetCharacterDataHandler</a></li> 118 1.1 tron <li><a href="#XML_SetProcessingInstructionHandler">XML_SetProcessingInstructionHandler</a></li> 119 1.1 tron <li><a href="#XML_SetCommentHandler">XML_SetCommentHandler</a></li> 120 1.1 tron <li><a href="#XML_SetStartCdataSectionHandler">XML_SetStartCdataSectionHandler</a></li> 121 1.1 tron <li><a href="#XML_SetEndCdataSectionHandler">XML_SetEndCdataSectionHandler</a></li> 122 1.1 tron <li><a href="#XML_SetCdataSectionHandler">XML_SetCdataSectionHandler</a></li> 123 1.1 tron <li><a href="#XML_SetDefaultHandler">XML_SetDefaultHandler</a></li> 124 1.1 tron <li><a href="#XML_SetDefaultHandlerExpand">XML_SetDefaultHandlerExpand</a></li> 125 1.1 tron <li><a href="#XML_SetExternalEntityRefHandler">XML_SetExternalEntityRefHandler</a></li> 126 1.1 tron <li><a href="#XML_SetExternalEntityRefHandlerArg">XML_SetExternalEntityRefHandlerArg</a></li> 127 1.1 tron <li><a href="#XML_SetSkippedEntityHandler">XML_SetSkippedEntityHandler</a></li> 128 1.1 tron <li><a href="#XML_SetUnknownEncodingHandler">XML_SetUnknownEncodingHandler</a></li> 129 1.1 tron <li><a href="#XML_SetStartNamespaceDeclHandler">XML_SetStartNamespaceDeclHandler</a></li> 130 1.1 tron <li><a href="#XML_SetEndNamespaceDeclHandler">XML_SetEndNamespaceDeclHandler</a></li> 131 1.1 tron <li><a href="#XML_SetNamespaceDeclHandler">XML_SetNamespaceDeclHandler</a></li> 132 1.1 tron <li><a href="#XML_SetXmlDeclHandler">XML_SetXmlDeclHandler</a></li> 133 1.1 tron <li><a href="#XML_SetStartDoctypeDeclHandler">XML_SetStartDoctypeDeclHandler</a></li> 134 1.1 tron <li><a href="#XML_SetEndDoctypeDeclHandler">XML_SetEndDoctypeDeclHandler</a></li> 135 1.1 tron <li><a href="#XML_SetDoctypeDeclHandler">XML_SetDoctypeDeclHandler</a></li> 136 1.1 tron <li><a href="#XML_SetElementDeclHandler">XML_SetElementDeclHandler</a></li> 137 1.1 tron <li><a href="#XML_SetAttlistDeclHandler">XML_SetAttlistDeclHandler</a></li> 138 1.1 tron <li><a href="#XML_SetEntityDeclHandler">XML_SetEntityDeclHandler</a></li> 139 1.1 tron <li><a href="#XML_SetUnparsedEntityDeclHandler">XML_SetUnparsedEntityDeclHandler</a></li> 140 1.1 tron <li><a href="#XML_SetNotationDeclHandler">XML_SetNotationDeclHandler</a></li> 141 1.1 tron <li><a href="#XML_SetNotStandaloneHandler">XML_SetNotStandaloneHandler</a></li> 142 1.1 tron </ul> 143 1.1 tron </li> 144 1.1 tron <li><a href="#position">Parse Position and Error Reporting Functions</a> 145 1.1 tron <ul> 146 1.1 tron <li><a href="#XML_GetErrorCode">XML_GetErrorCode</a></li> 147 1.1 tron <li><a href="#XML_ErrorString">XML_ErrorString</a></li> 148 1.1 tron <li><a href="#XML_GetCurrentByteIndex">XML_GetCurrentByteIndex</a></li> 149 1.1 tron <li><a href="#XML_GetCurrentLineNumber">XML_GetCurrentLineNumber</a></li> 150 1.1 tron <li><a href="#XML_GetCurrentColumnNumber">XML_GetCurrentColumnNumber</a></li> 151 1.1 tron <li><a href="#XML_GetCurrentByteCount">XML_GetCurrentByteCount</a></li> 152 1.1 tron <li><a href="#XML_GetInputContext">XML_GetInputContext</a></li> 153 1.1 tron </ul> 154 1.1 tron </li> 155 1.1.1.6 christos <li> 156 1.1.1.6.4.1 perseant <a href="#attack-protection">Attack Protection</a> 157 1.1.1.6 christos <ul> 158 1.1.1.6 christos <li><a href="#XML_SetBillionLaughsAttackProtectionMaximumAmplification">XML_SetBillionLaughsAttackProtectionMaximumAmplification</a></li> 159 1.1.1.6 christos <li><a href="#XML_SetBillionLaughsAttackProtectionActivationThreshold">XML_SetBillionLaughsAttackProtectionActivationThreshold</a></li> 160 1.1.1.6.4.1 perseant <li><a href="#XML_SetReparseDeferralEnabled">XML_SetReparseDeferralEnabled</a></li> 161 1.1.1.6 christos </ul> 162 1.1.1.6 christos </li> 163 1.1 tron <li><a href="#miscellaneous">Miscellaneous Functions</a> 164 1.1 tron <ul> 165 1.1 tron <li><a href="#XML_SetUserData">XML_SetUserData</a></li> 166 1.1 tron <li><a href="#XML_GetUserData">XML_GetUserData</a></li> 167 1.1 tron <li><a href="#XML_UseParserAsHandlerArg">XML_UseParserAsHandlerArg</a></li> 168 1.1 tron <li><a href="#XML_SetBase">XML_SetBase</a></li> 169 1.1 tron <li><a href="#XML_GetBase">XML_GetBase</a></li> 170 1.1 tron <li><a href="#XML_GetSpecifiedAttributeCount">XML_GetSpecifiedAttributeCount</a></li> 171 1.1 tron <li><a href="#XML_GetIdAttributeIndex">XML_GetIdAttributeIndex</a></li> 172 1.1.1.2 spz <li><a href="#XML_GetAttributeInfo">XML_GetAttributeInfo</a></li> 173 1.1 tron <li><a href="#XML_SetEncoding">XML_SetEncoding</a></li> 174 1.1 tron <li><a href="#XML_SetParamEntityParsing">XML_SetParamEntityParsing</a></li> 175 1.1.1.2 spz <li><a href="#XML_SetHashSalt">XML_SetHashSalt</a></li> 176 1.1 tron <li><a href="#XML_UseForeignDTD">XML_UseForeignDTD</a></li> 177 1.1 tron <li><a href="#XML_SetReturnNSTriplet">XML_SetReturnNSTriplet</a></li> 178 1.1 tron <li><a href="#XML_DefaultCurrent">XML_DefaultCurrent</a></li> 179 1.1 tron <li><a href="#XML_ExpatVersion">XML_ExpatVersion</a></li> 180 1.1 tron <li><a href="#XML_ExpatVersionInfo">XML_ExpatVersionInfo</a></li> 181 1.1 tron <li><a href="#XML_GetFeatureList">XML_GetFeatureList</a></li> 182 1.1 tron <li><a href="#XML_FreeContentModel">XML_FreeContentModel</a></li> 183 1.1 tron <li><a href="#XML_MemMalloc">XML_MemMalloc</a></li> 184 1.1 tron <li><a href="#XML_MemRealloc">XML_MemRealloc</a></li> 185 1.1 tron <li><a href="#XML_MemFree">XML_MemFree</a></li> 186 1.1 tron </ul> 187 1.1 tron </li> 188 1.1 tron </ul> 189 1.1 tron </li> 190 1.1 tron </ul> 191 1.1 tron 192 1.1 tron <hr /> 193 1.1 tron <h2><a name="overview">Overview</a></h2> 194 1.1 tron 195 1.1 tron <p>Expat is a stream-oriented parser. You register callback (or 196 1.1 tron handler) functions with the parser and then start feeding it the 197 1.1 tron document. As the parser recognizes parts of the document, it will 198 1.1 tron call the appropriate handler for that part (if you've registered one.) 199 1.1 tron The document is fed to the parser in pieces, so you can start parsing 200 1.1 tron before you have all the document. This also allows you to parse really 201 1.1 tron huge documents that won't fit into memory.</p> 202 1.1 tron 203 1.1 tron <p>Expat can be intimidating due to the many kinds of handlers and 204 1.1 tron options you can set. But you only need to learn four functions in 205 1.1 tron order to do 90% of what you'll want to do with it:</p> 206 1.1 tron 207 1.1 tron <dl> 208 1.1 tron 209 1.1 tron <dt><code><a href= "#XML_ParserCreate" 210 1.1 tron >XML_ParserCreate</a></code></dt> 211 1.1 tron <dd>Create a new parser object.</dd> 212 1.1 tron 213 1.1 tron <dt><code><a href= "#XML_SetElementHandler" 214 1.1 tron >XML_SetElementHandler</a></code></dt> 215 1.1 tron <dd>Set handlers for start and end tags.</dd> 216 1.1 tron 217 1.1 tron <dt><code><a href= "#XML_SetCharacterDataHandler" 218 1.1 tron >XML_SetCharacterDataHandler</a></code></dt> 219 1.1 tron <dd>Set handler for text.</dd> 220 1.1 tron 221 1.1 tron <dt><code><a href= "#XML_Parse" 222 1.1 tron >XML_Parse</a></code></dt> 223 1.1 tron <dd>Pass a buffer full of document to the parser</dd> 224 1.1 tron </dl> 225 1.1 tron 226 1.1 tron <p>These functions and others are described in the <a 227 1.1 tron href="#reference">reference</a> part of this document. The reference 228 1.1 tron section also describes in detail the parameters passed to the 229 1.1 tron different types of handlers.</p> 230 1.1 tron 231 1.1 tron <p>Let's look at a very simple example program that only uses 3 of the 232 1.1 tron above functions (it doesn't need to set a character handler.) The 233 1.1 tron program <a href="../examples/outline.c">outline.c</a> prints an 234 1.1 tron element outline, indenting child elements to distinguish them from the 235 1.1 tron parent element that contains them. The start handler does all the 236 1.1 tron work. It prints two indenting spaces for every level of ancestor 237 1.1 tron elements, then it prints the element and attribute 238 1.1 tron information. Finally it increments the global <code>Depth</code> 239 1.1 tron variable.</p> 240 1.1 tron 241 1.1 tron <pre class="eg"> 242 1.1 tron int Depth; 243 1.1 tron 244 1.1 tron void XMLCALL 245 1.1 tron start(void *data, const char *el, const char **attr) { 246 1.1 tron int i; 247 1.1 tron 248 1.1 tron for (i = 0; i < Depth; i++) 249 1.1 tron printf(" "); 250 1.1 tron 251 1.1 tron printf("%s", el); 252 1.1 tron 253 1.1 tron for (i = 0; attr[i]; i += 2) { 254 1.1 tron printf(" %s='%s'", attr[i], attr[i + 1]); 255 1.1 tron } 256 1.1 tron 257 1.1 tron printf("\n"); 258 1.1 tron Depth++; 259 1.1 tron } /* End of start handler */ 260 1.1 tron </pre> 261 1.1 tron 262 1.1 tron <p>The end tag simply does the bookkeeping work of decrementing 263 1.1 tron <code>Depth</code>.</p> 264 1.1 tron <pre class="eg"> 265 1.1 tron void XMLCALL 266 1.1 tron end(void *data, const char *el) { 267 1.1 tron Depth--; 268 1.1 tron } /* End of end handler */ 269 1.1 tron </pre> 270 1.1 tron 271 1.1 tron <p>Note the <code>XMLCALL</code> annotation used for the callbacks. 272 1.1 tron This is used to ensure that the Expat and the callbacks are using the 273 1.1 tron same calling convention in case the compiler options used for Expat 274 1.1 tron itself and the client code are different. Expat tries not to care 275 1.1 tron what the default calling convention is, though it may require that it 276 1.1 tron be compiled with a default convention of "cdecl" on some platforms. 277 1.1 tron For code which uses Expat, however, the calling convention is 278 1.1 tron specified by the <code>XMLCALL</code> annotation on most platforms; 279 1.1 tron callbacks should be defined using this annotation.</p> 280 1.1 tron 281 1.1 tron <p>The <code>XMLCALL</code> annotation was added in Expat 1.95.7, but 282 1.1 tron existing working Expat applications don't need to add it (since they 283 1.1 tron are already using the "cdecl" calling convention, or they wouldn't be 284 1.1 tron working). The annotation is only needed if the default calling 285 1.1 tron convention may be something other than "cdecl". To use the annotation 286 1.1 tron safely with older versions of Expat, you can conditionally define it 287 1.1 tron <em>after</em> including Expat's header file:</p> 288 1.1 tron 289 1.1 tron <pre class="eg"> 290 1.1 tron #include <expat.h> 291 1.1 tron 292 1.1 tron #ifndef XMLCALL 293 1.1 tron #if defined(_MSC_EXTENSIONS) && !defined(__BEOS__) && !defined(__CYGWIN__) 294 1.1 tron #define XMLCALL __cdecl 295 1.1 tron #elif defined(__GNUC__) 296 1.1 tron #define XMLCALL __attribute__((cdecl)) 297 1.1 tron #else 298 1.1 tron #define XMLCALL 299 1.1 tron #endif 300 1.1 tron #endif 301 1.1 tron </pre> 302 1.1 tron 303 1.1 tron <p>After creating the parser, the main program just has the job of 304 1.1 tron shoveling the document to the parser so that it can do its work.</p> 305 1.1 tron 306 1.1 tron <hr /> 307 1.1 tron <h2><a name="building">Building and Installing Expat</a></h2> 308 1.1 tron 309 1.1 tron <p>The Expat distribution comes as a compressed (with GNU gzip) tar 310 1.1 tron file. You may download the latest version from <a href= 311 1.1.1.6.4.1 perseant "https://sourceforge.net/projects/expat/" >Source Forge</a>. After 312 1.1 tron unpacking this, cd into the directory. Then follow either the Win32 313 1.1 tron directions or Unix directions below.</p> 314 1.1 tron 315 1.1 tron <h3>Building under Win32</h3> 316 1.1 tron 317 1.1 tron <p>If you're using the GNU compiler under cygwin, follow the Unix 318 1.1 tron directions in the next section. Otherwise if you have Microsoft's 319 1.1.1.5 maya Developer Studio installed, 320 1.1.1.5 maya you can use CMake to generate a <code>.sln</code> file, e.g. 321 1.1.1.5 maya <code> 322 1.1.1.6.4.1 perseant cmake -G"Visual Studio 16 2019" -DCMAKE_BUILD_TYPE=RelWithDebInfo . 323 1.1.1.5 maya </code>, and build Expat using <code>msbuild /m expat.sln</code> after.</p> 324 1.1 tron 325 1.1 tron <p>Alternatively, you may download the Win32 binary package that 326 1.1 tron contains the "expat.h" include file and a pre-built DLL.</p> 327 1.1 tron 328 1.1 tron <h3>Building under Unix (or GNU)</h3> 329 1.1 tron 330 1.1 tron <p>First you'll need to run the configure shell script in order to 331 1.1 tron configure the Makefiles and headers for your system.</p> 332 1.1 tron 333 1.1 tron <p>If you're happy with all the defaults that configure picks for you, 334 1.1 tron and you have permission on your system to install into /usr/local, you 335 1.1 tron can install Expat with this sequence of commands:</p> 336 1.1 tron 337 1.1 tron <pre class="eg"> 338 1.1 tron ./configure 339 1.1 tron make 340 1.1 tron make install 341 1.1 tron </pre> 342 1.1 tron 343 1.1 tron <p>There are some options that you can provide to this script, but the 344 1.1 tron only one we'll mention here is the <code>--prefix</code> option. You 345 1.1 tron can find out all the options available by running configure with just 346 1.1 tron the <code>--help</code> option.</p> 347 1.1 tron 348 1.1 tron <p>By default, the configure script sets things up so that the library 349 1.1 tron gets installed in <code>/usr/local/lib</code> and the associated 350 1.1 tron header file in <code>/usr/local/include</code>. But if you were to 351 1.1 tron give the option, <code>--prefix=/home/me/mystuff</code>, then the 352 1.1 tron library and header would get installed in 353 1.1 tron <code>/home/me/mystuff/lib</code> and 354 1.1 tron <code>/home/me/mystuff/include</code> respectively.</p> 355 1.1 tron 356 1.1 tron <h3>Configuring Expat Using the Pre-Processor</h3> 357 1.1 tron 358 1.1 tron <p>Expat's feature set can be configured using a small number of 359 1.1.1.6.4.1 perseant pre-processor definitions. The symbols are:</p> 360 1.1 tron 361 1.1 tron <dl class="cpp-symbols"> 362 1.1.1.6.4.1 perseant <dt><a name="XML_GE">XML_GE</a></dt> 363 1.1.1.6.4.1 perseant <dd> 364 1.1.1.6.4.1 perseant Added in Expat 2.6.0. 365 1.1.1.6.4.1 perseant Include support for 366 1.1.1.6.4.1 perseant <a href="https://www.w3.org/TR/2006/REC-xml-20060816/#sec-physical-struct">general entities</a> 367 1.1.1.6.4.1 perseant (syntax <code>&e1;</code> to reference and 368 1.1.1.6.4.1 perseant syntax <code><!ENTITY e1 'value1'></code> (an internal general entity) or 369 1.1.1.6.4.1 perseant <code><!ENTITY e2 SYSTEM 'file2'></code> (an external general entity) to declare). 370 1.1.1.6.4.1 perseant With <code>XML_GE</code> enabled, general entities will be replaced by their declared replacement text; 371 1.1.1.6.4.1 perseant for this to work for <em>external</em> general entities, in addition an 372 1.1.1.6.4.1 perseant <code><a href="#XML_SetExternalEntityRefHandler">XML_ExternalEntityRefHandler</a></code> must be set using 373 1.1.1.6.4.1 perseant <code><a href="#XML_SetExternalEntityRefHandler">XML_SetExternalEntityRefHandler</a></code>. 374 1.1.1.6.4.1 perseant Also, enabling <code>XML_GE</code> makes 375 1.1.1.6.4.1 perseant the functions <code><a href="#XML_SetBillionLaughsAttackProtectionMaximumAmplification"> 376 1.1.1.6.4.1 perseant XML_SetBillionLaughsAttackProtectionMaximumAmplification</a></code> and <code> 377 1.1.1.6.4.1 perseant <a href="#XML_SetBillionLaughsAttackProtectionActivationThreshold"> 378 1.1.1.6.4.1 perseant XML_SetBillionLaughsAttackProtectionActivationThreshold</a></code> available. 379 1.1.1.6.4.1 perseant <br/> 380 1.1.1.6.4.1 perseant With <code>XML_GE</code> disabled, Expat has a smaller memory footprint and can be faster, but will 381 1.1.1.6.4.1 perseant not load external general entities and will replace all general entities 382 1.1.1.6.4.1 perseant (except the <a href="https://www.w3.org/TR/2006/REC-xml-20060816/#sec-predefined-ent">predefined five</a>: 383 1.1.1.6.4.1 perseant <code>amp</code>, <code>apos</code>, <code>gt</code>, <code>lt</code>, <code>quot</code>) 384 1.1.1.6.4.1 perseant with a self-reference: 385 1.1.1.6.4.1 perseant for example, referencing an entity <code>e1</code> via <code>&e1;</code> will be replaced 386 1.1.1.6.4.1 perseant by text <code>&e1;</code>. 387 1.1.1.6.4.1 perseant </dd> 388 1.1.1.6.4.1 perseant 389 1.1.1.6.4.1 perseant <dt><a name="XML_DTD">XML_DTD</a></dt> 390 1.1 tron <dd>Include support for using and reporting DTD-based content. If 391 1.1 tron this is defined, default attribute values from an external DTD subset 392 1.1 tron are reported and attribute value normalization occurs based on the 393 1.1 tron type of attributes defined in the external subset. Without 394 1.1 tron this, Expat has a smaller memory footprint and can be faster, but will 395 1.1.1.6.4.1 perseant not load external parameter entities or process conditional sections. If defined, makes 396 1.1.1.6.4.1 perseant the functions <code><a 397 1.1.1.6.4.1 perseant href="#XML_SetBillionLaughsAttackProtectionMaximumAmplification"> 398 1.1.1.6.4.1 perseant XML_SetBillionLaughsAttackProtectionMaximumAmplification</a></code> and <code> 399 1.1.1.6.4.1 perseant <a href="#XML_SetBillionLaughsAttackProtectionActivationThreshold"> 400 1.1.1.6.4.1 perseant XML_SetBillionLaughsAttackProtectionActivationThreshold</a></code> available.</dd> 401 1.1 tron 402 1.1.1.6.4.1 perseant <dt><a name="XML_NS">XML_NS</a></dt> 403 1.1 tron <dd>When defined, support for the <cite><a href= 404 1.1.1.6.4.1 perseant "https://www.w3.org/TR/REC-xml-names/" >Namespaces in XML</a></cite> 405 1.1 tron specification is included.</dd> 406 1.1 tron 407 1.1.1.6.4.1 perseant <dt><a name="XML_UNICODE">XML_UNICODE</a></dt> 408 1.1 tron <dd>When defined, character data reported to the application is 409 1.1 tron encoded in UTF-16 using wide characters of the type 410 1.1 tron <code>XML_Char</code>. This is implied if 411 1.1 tron <code>XML_UNICODE_WCHAR_T</code> is defined.</dd> 412 1.1 tron 413 1.1.1.6.4.1 perseant <dt><a name="XML_UNICODE_WCHAR_T">XML_UNICODE_WCHAR_T</a></dt> 414 1.1 tron <dd>If defined, causes the <code>XML_Char</code> character type to be 415 1.1 tron defined using the <code>wchar_t</code> type; otherwise, <code>unsigned 416 1.1 tron short</code> is used. Defining this implies 417 1.1 tron <code>XML_UNICODE</code>.</dd> 418 1.1 tron 419 1.1.1.6.4.1 perseant <dt><a name="XML_LARGE_SIZE">XML_LARGE_SIZE</a></dt> 420 1.1 tron <dd>If defined, causes the <code>XML_Size</code> and <code>XML_Index</code> 421 1.1 tron integer types to be at least 64 bits in size. This is intended to support 422 1.1 tron processing of very large input streams, where the return values of 423 1.1 tron <code><a href="#XML_GetCurrentByteIndex" >XML_GetCurrentByteIndex</a></code>, 424 1.1 tron <code><a href="#XML_GetCurrentLineNumber" >XML_GetCurrentLineNumber</a></code> and 425 1.1 tron <code><a href="#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code> 426 1.1 tron could overflow. It may not be supported by all compilers, and is turned 427 1.1 tron off by default.</dd> 428 1.1 tron 429 1.1.1.6.4.1 perseant <dt><a name="XML_CONTEXT_BYTES">XML_CONTEXT_BYTES</a></dt> 430 1.1 tron <dd>The number of input bytes of markup context which the parser will 431 1.1 tron ensure are available for reporting via <code><a href= 432 1.1 tron "#XML_GetInputContext" >XML_GetInputContext</a></code>. This is 433 1.1.1.6.4.1 perseant normally set to 1024, and must be set to a positive integer to enable. 434 1.1.1.6.4.1 perseant If this is set to zero, the input context will not be available and <code><a 435 1.1 tron href= "#XML_GetInputContext" >XML_GetInputContext</a></code> will 436 1.1.1.6.4.1 perseant always report <code>NULL</code>. Without this, Expat has a smaller memory 437 1.1 tron footprint and can be faster.</dd> 438 1.1 tron 439 1.1.1.6.4.1 perseant <dt><a name="XML_STATIC">XML_STATIC</a></dt> 440 1.1 tron <dd>On Windows, this should be set if Expat is going to be linked 441 1.1 tron statically with the code that calls it; this is required to get all 442 1.1 tron the right MSVC magic annotations correct. This is ignored on other 443 1.1 tron platforms.</dd> 444 1.1.1.2 spz 445 1.1.1.6.4.1 perseant <dt><a name="XML_ATTR_INFO">XML_ATTR_INFO</a></dt> 446 1.1.1.5 maya <dd>If defined, makes the additional function <code><a href= 447 1.1.1.2 spz "#XML_GetAttributeInfo" >XML_GetAttributeInfo</a></code> available 448 1.1.1.2 spz for reporting attribute byte offsets.</dd> 449 1.1 tron </dl> 450 1.1 tron 451 1.1 tron <hr /> 452 1.1 tron <h2><a name="using">Using Expat</a></h2> 453 1.1 tron 454 1.1 tron <h3>Compiling and Linking Against Expat</h3> 455 1.1 tron 456 1.1 tron <p>Unless you installed Expat in a location not expected by your 457 1.1 tron compiler and linker, all you have to do to use Expat in your programs 458 1.1 tron is to include the Expat header (<code>#include <expat.h></code>) 459 1.1 tron in your files that make calls to it and to tell the linker that it 460 1.1 tron needs to link against the Expat library. On Unix systems, this would 461 1.1 tron usually be done with the <code>-lexpat</code> argument. Otherwise, 462 1.1 tron you'll need to tell the compiler where to look for the Expat header 463 1.1 tron and the linker where to find the Expat library. You may also need to 464 1.1 tron take steps to tell the operating system where to find this library at 465 1.1 tron run time.</p> 466 1.1 tron 467 1.1 tron <p>On a Unix-based system, here's what a Makefile might look like when 468 1.1 tron Expat is installed in a standard location:</p> 469 1.1 tron 470 1.1 tron <pre class="eg"> 471 1.1 tron CC=cc 472 1.1 tron LDFLAGS= 473 1.1 tron LIBS= -lexpat 474 1.1 tron xmlapp: xmlapp.o 475 1.1 tron $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS) 476 1.1 tron </pre> 477 1.1 tron 478 1.1 tron <p>If you installed Expat in, say, <code>/home/me/mystuff</code>, then 479 1.1 tron the Makefile would look like this:</p> 480 1.1 tron 481 1.1 tron <pre class="eg"> 482 1.1 tron CC=cc 483 1.1 tron CFLAGS= -I/home/me/mystuff/include 484 1.1 tron LDFLAGS= 485 1.1 tron LIBS= -L/home/me/mystuff/lib -lexpat 486 1.1 tron xmlapp: xmlapp.o 487 1.1 tron $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS) 488 1.1 tron </pre> 489 1.1 tron 490 1.1 tron <p>You'd also have to set the environment variable 491 1.1 tron <code>LD_LIBRARY_PATH</code> to <code>/home/me/mystuff/lib</code> (or 492 1.1 tron to <code>${LD_LIBRARY_PATH}:/home/me/mystuff/lib</code> if 493 1.1 tron LD_LIBRARY_PATH already has some directories in it) in order to run 494 1.1 tron your application.</p> 495 1.1 tron 496 1.1 tron <h3>Expat Basics</h3> 497 1.1 tron 498 1.1 tron <p>As we saw in the example in the overview, the first step in parsing 499 1.1 tron an XML document with Expat is to create a parser object. There are <a 500 1.1 tron href="#creation">three functions</a> in the Expat API for creating a 501 1.1 tron parser object. However, only two of these (<code><a href= 502 1.1 tron "#XML_ParserCreate" >XML_ParserCreate</a></code> and <code><a href= 503 1.1 tron "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>) can be used for 504 1.1 tron constructing a parser for a top-level document. The object returned 505 1.1 tron by these functions is an opaque pointer (i.e. "expat.h" declares it as 506 1.1 tron void *) to data with further internal structure. In order to free the 507 1.1 tron memory associated with this object you must call <code><a href= 508 1.1 tron "#XML_ParserFree" >XML_ParserFree</a></code>. Note that if you have 509 1.1 tron provided any <a href="#userdata">user data</a> that gets stored in the 510 1.1 tron parser, then your application is responsible for freeing it prior to 511 1.1 tron calling <code>XML_ParserFree</code>.</p> 512 1.1 tron 513 1.1 tron <p>The objects returned by the parser creation functions are good for 514 1.1 tron parsing only one XML document or external parsed entity. If your 515 1.1 tron application needs to parse many XML documents, then it needs to create 516 1.1 tron a parser object for each one. The best way to deal with this is to 517 1.1 tron create a higher level object that contains all the default 518 1.1 tron initialization you want for your parser objects.</p> 519 1.1 tron 520 1.1 tron <p>Walking through a document hierarchy with a stream oriented parser 521 1.1 tron will require a good stack mechanism in order to keep track of current 522 1.1 tron context. For instance, to answer the simple question, "What element 523 1.1 tron does this text belong to?" requires a stack, since the parser may have 524 1.1 tron descended into other elements that are children of the current one and 525 1.1 tron has encountered this text on the way out.</p> 526 1.1 tron 527 1.1 tron <p>The things you're likely to want to keep on a stack are the 528 1.1 tron currently opened element and it's attributes. You push this 529 1.1 tron information onto the stack in the start handler and you pop it off in 530 1.1 tron the end handler.</p> 531 1.1 tron 532 1.1 tron <p>For some tasks, it is sufficient to just keep information on what 533 1.1 tron the depth of the stack is (or would be if you had one.) The outline 534 1.1 tron program shown above presents one example. Another such task would be 535 1.1 tron skipping over a complete element. When you see the start tag for the 536 1.1 tron element you want to skip, you set a skip flag and record the depth at 537 1.1 tron which the element started. When the end tag handler encounters the 538 1.1 tron same depth, the skipped element has ended and the flag may be 539 1.1 tron cleared. If you follow the convention that the root element starts at 540 1.1 tron 1, then you can use the same variable for skip flag and skip 541 1.1 tron depth.</p> 542 1.1 tron 543 1.1 tron <pre class="eg"> 544 1.1 tron void 545 1.1 tron init_info(Parseinfo *info) { 546 1.1 tron info->skip = 0; 547 1.1 tron info->depth = 1; 548 1.1 tron /* Other initializations here */ 549 1.1 tron } /* End of init_info */ 550 1.1 tron 551 1.1 tron void XMLCALL 552 1.1 tron rawstart(void *data, const char *el, const char **attr) { 553 1.1 tron Parseinfo *inf = (Parseinfo *) data; 554 1.1 tron 555 1.1 tron if (! inf->skip) { 556 1.1 tron if (should_skip(inf, el, attr)) { 557 1.1 tron inf->skip = inf->depth; 558 1.1 tron } 559 1.1 tron else 560 1.1 tron start(inf, el, attr); /* This does rest of start handling */ 561 1.1 tron } 562 1.1 tron 563 1.1 tron inf->depth++; 564 1.1 tron } /* End of rawstart */ 565 1.1 tron 566 1.1 tron void XMLCALL 567 1.1 tron rawend(void *data, const char *el) { 568 1.1 tron Parseinfo *inf = (Parseinfo *) data; 569 1.1 tron 570 1.1 tron inf->depth--; 571 1.1 tron 572 1.1 tron if (! inf->skip) 573 1.1 tron end(inf, el); /* This does rest of end handling */ 574 1.1 tron 575 1.1 tron if (inf->skip == inf->depth) 576 1.1 tron inf->skip = 0; 577 1.1 tron } /* End rawend */ 578 1.1 tron </pre> 579 1.1 tron 580 1.1 tron <p>Notice in the above example the difference in how depth is 581 1.1 tron manipulated in the start and end handlers. The end tag handler should 582 1.1 tron be the mirror image of the start tag handler. This is necessary to 583 1.1 tron properly model containment. Since, in the start tag handler, we 584 1.1 tron incremented depth <em>after</em> the main body of start tag code, then 585 1.1 tron in the end handler, we need to manipulate it <em>before</em> the main 586 1.1 tron body. If we'd decided to increment it first thing in the start 587 1.1 tron handler, then we'd have had to decrement it last thing in the end 588 1.1 tron handler.</p> 589 1.1 tron 590 1.1 tron <h3 id="userdata">Communicating between handlers</h3> 591 1.1 tron 592 1.1 tron <p>In order to be able to pass information between different handlers 593 1.1 tron without using globals, you'll need to define a data structure to hold 594 1.1 tron the shared variables. You can then tell Expat (with the <code><a href= 595 1.1 tron "#XML_SetUserData" >XML_SetUserData</a></code> function) to pass a 596 1.1 tron pointer to this structure to the handlers. This is the first 597 1.1 tron argument received by most handlers. In the <a href="#reference" 598 1.1 tron >reference section</a>, an argument to a callback function is named 599 1.1 tron <code>userData</code> and have type <code>void *</code> if the user 600 1.1 tron data is passed; it will have the type <code>XML_Parser</code> if the 601 1.1 tron parser itself is passed. When the parser is passed, the user data may 602 1.1 tron be retrieved using <code><a href="#XML_GetUserData" 603 1.1 tron >XML_GetUserData</a></code>.</p> 604 1.1 tron 605 1.1 tron <p>One common case where multiple calls to a single handler may need 606 1.1 tron to communicate using an application data structure is the case when 607 1.1 tron content passed to the character data handler (set by <code><a href= 608 1.1 tron "#XML_SetCharacterDataHandler" 609 1.1 tron >XML_SetCharacterDataHandler</a></code>) needs to be accumulated. A 610 1.1 tron common first-time mistake with any of the event-oriented interfaces to 611 1.1 tron an XML parser is to expect all the text contained in an element to be 612 1.1 tron reported by a single call to the character data handler. Expat, like 613 1.1 tron many other XML parsers, reports such data as a sequence of calls; 614 1.1 tron there's no way to know when the end of the sequence is reached until a 615 1.1 tron different callback is made. A buffer referenced by the user data 616 1.1 tron structure proves both an effective and convenient place to accumulate 617 1.1 tron character data.</p> 618 1.1 tron 619 1.1 tron <!-- XXX example needed here --> 620 1.1 tron 621 1.1 tron 622 1.1 tron <h3>XML Version</h3> 623 1.1 tron 624 1.1 tron <p>Expat is an XML 1.0 parser, and as such never complains based on 625 1.1 tron the value of the <code>version</code> pseudo-attribute in the XML 626 1.1 tron declaration, if present.</p> 627 1.1 tron 628 1.1 tron <p>If an application needs to check the version number (to support 629 1.1 tron alternate processing), it should use the <code><a href= 630 1.1 tron "#XML_SetXmlDeclHandler" >XML_SetXmlDeclHandler</a></code> function to 631 1.1 tron set a handler that uses the information in the XML declaration to 632 1.1 tron determine what to do. This example shows how to check that only a 633 1.1 tron version number of <code>"1.0"</code> is accepted:</p> 634 1.1 tron 635 1.1 tron <pre class="eg"> 636 1.1 tron static int wrong_version; 637 1.1 tron static XML_Parser parser; 638 1.1 tron 639 1.1 tron static void XMLCALL 640 1.1 tron xmldecl_handler(void *userData, 641 1.1 tron const XML_Char *version, 642 1.1 tron const XML_Char *encoding, 643 1.1 tron int standalone) 644 1.1 tron { 645 1.1 tron static const XML_Char Version_1_0[] = {'1', '.', '0', 0}; 646 1.1 tron 647 1.1 tron int i; 648 1.1 tron 649 1.1 tron for (i = 0; i < (sizeof(Version_1_0) / sizeof(Version_1_0[0])); ++i) { 650 1.1 tron if (version[i] != Version_1_0[i]) { 651 1.1 tron wrong_version = 1; 652 1.1 tron /* also clear all other handlers: */ 653 1.1 tron XML_SetCharacterDataHandler(parser, NULL); 654 1.1 tron ... 655 1.1 tron return; 656 1.1 tron } 657 1.1 tron } 658 1.1 tron ... 659 1.1 tron } 660 1.1 tron </pre> 661 1.1 tron 662 1.1 tron <h3>Namespace Processing</h3> 663 1.1 tron 664 1.1 tron <p>When the parser is created using the <code><a href= 665 1.1 tron "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>, function, Expat 666 1.1 tron performs namespace processing. Under namespace processing, Expat 667 1.1 tron consumes <code>xmlns</code> and <code>xmlns:...</code> attributes, 668 1.1 tron which declare namespaces for the scope of the element in which they 669 1.1 tron occur. This means that your start handler will not see these 670 1.1 tron attributes. Your application can still be informed of these 671 1.1 tron declarations by setting namespace declaration handlers with <a href= 672 1.1 tron "#XML_SetNamespaceDeclHandler" 673 1.1 tron ><code>XML_SetNamespaceDeclHandler</code></a>.</p> 674 1.1 tron 675 1.1 tron <p>Element type and attribute names that belong to a given namespace 676 1.1 tron are passed to the appropriate handler in expanded form. By default 677 1.1 tron this expanded form is a concatenation of the namespace URI, the 678 1.1 tron separator character (which is the 2nd argument to <code><a href= 679 1.1 tron "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>), and the local 680 1.1 tron name (i.e. the part after the colon). Names with undeclared prefixes 681 1.1 tron are not well-formed when namespace processing is enabled, and will 682 1.1 tron trigger an error. Unprefixed attribute names are never expanded, 683 1.1 tron and unprefixed element names are only expanded when they are in the 684 1.1 tron scope of a default namespace.</p> 685 1.1 tron 686 1.1 tron <p>However if <code><a href= "#XML_SetReturnNSTriplet" 687 1.1 tron >XML_SetReturnNSTriplet</a></code> has been called with a non-zero 688 1.1 tron <code>do_nst</code> parameter, then the expanded form for names with 689 1.1 tron an explicit prefix is a concatenation of: URI, separator, local name, 690 1.1 tron separator, prefix.</p> 691 1.1 tron 692 1.1 tron <p>You can set handlers for the start of a namespace declaration and 693 1.1 tron for the end of a scope of a declaration with the <code><a href= 694 1.1 tron "#XML_SetNamespaceDeclHandler" >XML_SetNamespaceDeclHandler</a></code> 695 1.1 tron function. The StartNamespaceDeclHandler is called prior to the start 696 1.1 tron tag handler and the EndNamespaceDeclHandler is called after the 697 1.1 tron corresponding end tag that ends the namespace's scope. The namespace 698 1.1 tron start handler gets passed the prefix and URI for the namespace. For a 699 1.1.1.6.4.1 perseant default namespace declaration (xmlns='...'), the prefix will be 700 1.1.1.6.4.1 perseant <code>NULL</code>. 701 1.1.1.6.4.1 perseant The URI will be <code>NULL</code> for the case where the default namespace is being 702 1.1 tron unset. The namespace end handler just gets the prefix for the closing 703 1.1 tron scope.</p> 704 1.1 tron 705 1.1 tron <p>These handlers are called for each declaration. So if, for 706 1.1 tron instance, a start tag had three namespace declarations, then the 707 1.1 tron StartNamespaceDeclHandler would be called three times before the start 708 1.1 tron tag handler is called, once for each declaration.</p> 709 1.1 tron 710 1.1 tron <h3>Character Encodings</h3> 711 1.1 tron 712 1.1 tron <p>While XML is based on Unicode, and every XML processor is required 713 1.1 tron to recognized UTF-8 and UTF-16 (1 and 2 byte encodings of Unicode), 714 1.1 tron other encodings may be declared in XML documents or entities. For the 715 1.1 tron main document, an XML declaration may contain an encoding 716 1.1 tron declaration:</p> 717 1.1 tron <pre> 718 1.1 tron <?xml version="1.0" encoding="ISO-8859-2"?> 719 1.1 tron </pre> 720 1.1 tron 721 1.1 tron <p>External parsed entities may begin with a text declaration, which 722 1.1 tron looks like an XML declaration with just an encoding declaration:</p> 723 1.1 tron <pre> 724 1.1 tron <?xml encoding="Big5"?> 725 1.1 tron </pre> 726 1.1 tron 727 1.1 tron <p>With Expat, you may also specify an encoding at the time of 728 1.1 tron creating a parser. This is useful when the encoding information may 729 1.1 tron come from a source outside the document itself (like a higher level 730 1.1 tron protocol.)</p> 731 1.1 tron 732 1.1 tron <p><a name="builtin_encodings"></a>There are four built-in encodings 733 1.1 tron in Expat:</p> 734 1.1 tron <ul> 735 1.1 tron <li>UTF-8</li> 736 1.1 tron <li>UTF-16</li> 737 1.1 tron <li>ISO-8859-1</li> 738 1.1 tron <li>US-ASCII</li> 739 1.1 tron </ul> 740 1.1 tron 741 1.1 tron <p>Anything else discovered in an encoding declaration or in the 742 1.1 tron protocol encoding specified in the parser constructor, triggers a call 743 1.1 tron to the <code>UnknownEncodingHandler</code>. This handler gets passed 744 1.1 tron the encoding name and a pointer to an <code>XML_Encoding</code> data 745 1.1 tron structure. Your handler must fill in this structure and return 746 1.1 tron <code>XML_STATUS_OK</code> if it knows how to deal with the 747 1.1 tron encoding. Otherwise the handler should return 748 1.1 tron <code>XML_STATUS_ERROR</code>. The handler also gets passed a pointer 749 1.1 tron to an optional application data structure that you may indicate when 750 1.1 tron you set the handler.</p> 751 1.1 tron 752 1.1 tron <p>Expat places restrictions on character encodings that it can 753 1.1 tron support by filling in the <code>XML_Encoding</code> structure. 754 1.1 tron include file:</p> 755 1.1 tron <ol> 756 1.1 tron <li>Every ASCII character that can appear in a well-formed XML document 757 1.1 tron must be represented by a single byte, and that byte must correspond to 758 1.1 tron it's ASCII encoding (except for the characters $@\^'{}~)</li> 759 1.1 tron <li>Characters must be encoded in 4 bytes or less.</li> 760 1.1 tron <li>All characters encoded must have Unicode scalar values less than or 761 1.1 tron equal to 65535 (0xFFFF)<em>This does not apply to the built-in support 762 1.1 tron for UTF-16 and UTF-8</em></li> 763 1.1 tron <li>No character may be encoded by more that one distinct sequence of 764 1.1 tron bytes</li> 765 1.1 tron </ol> 766 1.1 tron 767 1.1 tron <p><code>XML_Encoding</code> contains an array of integers that 768 1.1 tron correspond to the 1st byte of an encoding sequence. If the value in 769 1.1 tron the array for a byte is zero or positive, then the byte is a single 770 1.1 tron byte encoding that encodes the Unicode scalar value contained in the 771 1.1 tron array. A -1 in this array indicates a malformed byte. If the value is 772 1.1 tron -2, -3, or -4, then the byte is the beginning of a 2, 3, or 4 byte 773 1.1 tron sequence respectively. Multi-byte sequences are sent to the convert 774 1.1 tron function pointed at in the <code>XML_Encoding</code> structure. This 775 1.1 tron function should return the Unicode scalar value for the sequence or -1 776 1.1 tron if the sequence is malformed.</p> 777 1.1 tron 778 1.1 tron <p>One pitfall that novice Expat users are likely to fall into is that 779 1.1 tron although Expat may accept input in various encodings, the strings that 780 1.1 tron it passes to the handlers are always encoded in UTF-8 or UTF-16 781 1.1 tron (depending on how Expat was compiled). Your application is responsible 782 1.1 tron for any translation of these strings into other encodings.</p> 783 1.1 tron 784 1.1 tron <h3>Handling External Entity References</h3> 785 1.1 tron 786 1.1 tron <p>Expat does not read or parse external entities directly. Note that 787 1.1 tron any external DTD is a special case of an external entity. If you've 788 1.1 tron set no <code>ExternalEntityRefHandler</code>, then external entity 789 1.1 tron references are silently ignored. Otherwise, it calls your handler with 790 1.1 tron the information needed to read and parse the external entity.</p> 791 1.1 tron 792 1.1 tron <p>Your handler isn't actually responsible for parsing the entity, but 793 1.1 tron it is responsible for creating a subsidiary parser with <code><a href= 794 1.1 tron "#XML_ExternalEntityParserCreate" 795 1.1 tron >XML_ExternalEntityParserCreate</a></code> that will do the job. This 796 1.1 tron returns an instance of <code>XML_Parser</code> that has handlers and 797 1.1 tron other data structures initialized from the parent parser. You may then 798 1.1 tron use <code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a 799 1.1 tron href= "#XML_ParseBuffer">XML_ParseBuffer</a></code> calls against this 800 1.1 tron parser. Since external entities my refer to other external entities, 801 1.1 tron your handler should be prepared to be called recursively.</p> 802 1.1 tron 803 1.1 tron <h3>Parsing DTDs</h3> 804 1.1 tron 805 1.1 tron <p>In order to parse parameter entities, before starting the parse, 806 1.1 tron you must call <code><a href= "#XML_SetParamEntityParsing" 807 1.1 tron >XML_SetParamEntityParsing</a></code> with one of the following 808 1.1 tron arguments:</p> 809 1.1 tron <dl> 810 1.1 tron <dt><code>XML_PARAM_ENTITY_PARSING_NEVER</code></dt> 811 1.1 tron <dd>Don't parse parameter entities or the external subset</dd> 812 1.1 tron <dt><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></dt> 813 1.1.1.5 maya <dd>Parse parameter entities and the external subset unless 814 1.1 tron <code>standalone</code> was set to "yes" in the XML declaration.</dd> 815 1.1 tron <dt><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></dt> 816 1.1 tron <dd>Always parse parameter entities and the external subset</dd> 817 1.1 tron </dl> 818 1.1 tron 819 1.1 tron <p>In order to read an external DTD, you also have to set an external 820 1.1 tron entity reference handler as described above.</p> 821 1.1 tron 822 1.1 tron <h3 id="stop-resume">Temporarily Stopping Parsing</h3> 823 1.1 tron 824 1.1 tron <p>Expat 1.95.8 introduces a new feature: its now possible to stop 825 1.1 tron parsing temporarily from within a handler function, even if more data 826 1.1 tron has already been passed into the parser. Applications for this 827 1.1 tron include</p> 828 1.1 tron 829 1.1 tron <ul> 830 1.1.1.6.4.1 perseant <li>Supporting the <a href= "https://www.w3.org/TR/xinclude/" 831 1.1 tron >XInclude</a> specification.</li> 832 1.1 tron 833 1.1 tron <li>Delaying further processing until additional information is 834 1.1 tron available from some other source.</li> 835 1.1 tron 836 1.1 tron <li>Adjusting processor load as task priorities shift within an 837 1.1 tron application.</li> 838 1.1 tron 839 1.1 tron <li>Stopping parsing completely (simply free or reset the parser 840 1.1 tron instead of resuming in the outer parsing loop). This can be useful 841 1.1.1.5 maya if an application-domain error is found in the XML being parsed or if 842 1.1 tron the result of the parse is determined not to be useful after 843 1.1 tron all.</li> 844 1.1 tron </ul> 845 1.1 tron 846 1.1 tron <p>To take advantage of this feature, the main parsing loop of an 847 1.1 tron application needs to support this specifically. It cannot be 848 1.1 tron supported with a parsing loop compatible with Expat 1.95.7 or 849 1.1 tron earlier (though existing loops will continue to work without 850 1.1 tron supporting the stop/resume feature).</p> 851 1.1 tron 852 1.1 tron <p>An application that uses this feature for a single parser will have 853 1.1 tron the rough structure (in pseudo-code):</p> 854 1.1 tron 855 1.1 tron <pre class="pseudocode"> 856 1.1 tron fd = open_input() 857 1.1 tron p = create_parser() 858 1.1 tron 859 1.1 tron if parse_xml(p, fd) { 860 1.1 tron /* suspended */ 861 1.1 tron 862 1.1 tron int suspended = 1; 863 1.1 tron 864 1.1 tron while (suspended) { 865 1.1 tron do_something_else() 866 1.1 tron if ready_to_resume() { 867 1.1 tron suspended = continue_parsing(p, fd); 868 1.1 tron } 869 1.1 tron } 870 1.1 tron } 871 1.1 tron </pre> 872 1.1 tron 873 1.1 tron <p>An application that may resume any of several parsers based on 874 1.1 tron input (either from the XML being parsed or some other source) will 875 1.1 tron certainly have more interesting control structures.</p> 876 1.1 tron 877 1.1 tron <p>This C function could be used for the <code>parse_xml</code> 878 1.1 tron function mentioned in the pseudo-code above:</p> 879 1.1 tron 880 1.1 tron <pre class="eg"> 881 1.1 tron #define BUFF_SIZE 10240 882 1.1 tron 883 1.1 tron /* Parse a document from the open file descriptor 'fd' until the parse 884 1.1 tron is complete (the document has been completely parsed, or there's 885 1.1 tron been an error), or the parse is stopped. Return non-zero when 886 1.1 tron the parse is merely suspended. 887 1.1 tron */ 888 1.1 tron int 889 1.1 tron parse_xml(XML_Parser p, int fd) 890 1.1 tron { 891 1.1 tron for (;;) { 892 1.1 tron int last_chunk; 893 1.1 tron int bytes_read; 894 1.1 tron enum XML_Status status; 895 1.1 tron 896 1.1 tron void *buff = XML_GetBuffer(p, BUFF_SIZE); 897 1.1 tron if (buff == NULL) { 898 1.1 tron /* handle error... */ 899 1.1 tron return 0; 900 1.1 tron } 901 1.1 tron bytes_read = read(fd, buff, BUFF_SIZE); 902 1.1 tron if (bytes_read < 0) { 903 1.1 tron /* handle error... */ 904 1.1 tron return 0; 905 1.1 tron } 906 1.1 tron status = XML_ParseBuffer(p, bytes_read, bytes_read == 0); 907 1.1 tron switch (status) { 908 1.1 tron case XML_STATUS_ERROR: 909 1.1 tron /* handle error... */ 910 1.1 tron return 0; 911 1.1 tron case XML_STATUS_SUSPENDED: 912 1.1 tron return 1; 913 1.1 tron } 914 1.1 tron if (bytes_read == 0) 915 1.1 tron return 0; 916 1.1 tron } 917 1.1 tron } 918 1.1 tron </pre> 919 1.1 tron 920 1.1 tron <p>The corresponding <code>continue_parsing</code> function is 921 1.1 tron somewhat simpler, since it only need deal with the return code from 922 1.1 tron <code><a href= "#XML_ResumeParser">XML_ResumeParser</a></code>; it can 923 1.1 tron delegate the input handling to the <code>parse_xml</code> 924 1.1 tron function:</p> 925 1.1 tron 926 1.1 tron <pre class="eg"> 927 1.1 tron /* Continue parsing a document which had been suspended. The 'p' and 928 1.1 tron 'fd' arguments are the same as passed to parse_xml(). Return 929 1.1 tron non-zero when the parse is suspended. 930 1.1 tron */ 931 1.1 tron int 932 1.1 tron continue_parsing(XML_Parser p, int fd) 933 1.1 tron { 934 1.1 tron enum XML_Status status = XML_ResumeParser(p); 935 1.1 tron switch (status) { 936 1.1 tron case XML_STATUS_ERROR: 937 1.1 tron /* handle error... */ 938 1.1 tron return 0; 939 1.1 tron case XML_ERROR_NOT_SUSPENDED: 940 1.1 tron /* handle error... */ 941 1.1 tron return 0;. 942 1.1 tron case XML_STATUS_SUSPENDED: 943 1.1 tron return 1; 944 1.1 tron } 945 1.1 tron return parse_xml(p, fd); 946 1.1 tron } 947 1.1 tron </pre> 948 1.1 tron 949 1.1 tron <p>Now that we've seen what a mess the top-level parsing loop can 950 1.1 tron become, what have we gained? Very simply, we can now use the <code><a 951 1.1 tron href= "#XML_StopParser" >XML_StopParser</a></code> function to stop 952 1.1 tron parsing, without having to go to great lengths to avoid additional 953 1.1 tron processing that we're expecting to ignore. As a bonus, we get to stop 954 1.1 tron parsing <em>temporarily</em>, and come back to it when we're 955 1.1 tron ready.</p> 956 1.1 tron 957 1.1 tron <p>To stop parsing from a handler function, use the <code><a href= 958 1.1 tron "#XML_StopParser" >XML_StopParser</a></code> function. This function 959 1.1 tron takes two arguments; the parser being stopped and a flag indicating 960 1.1 tron whether the parse can be resumed in the future.</p> 961 1.1 tron 962 1.1 tron <!-- XXX really need more here --> 963 1.1 tron 964 1.1 tron 965 1.1 tron <hr /> 966 1.1 tron <!-- ================================================================ --> 967 1.1 tron 968 1.1 tron <h2><a name="reference">Expat Reference</a></h2> 969 1.1 tron 970 1.1 tron <h3><a name="creation">Parser Creation</a></h3> 971 1.1 tron 972 1.1.1.6 christos <h4 id="XML_ParserCreate">XML_ParserCreate</h4> 973 1.1.1.6 christos <pre class="fcndec"> 974 1.1 tron XML_Parser XMLCALL 975 1.1 tron XML_ParserCreate(const XML_Char *encoding); 976 1.1 tron </pre> 977 1.1 tron <div class="fcndef"> 978 1.1.1.6.4.1 perseant <p> 979 1.1.1.6.4.1 perseant Construct a new parser. If encoding is non-<code>NULL</code>, it specifies a 980 1.1 tron character encoding to use for the document. This overrides the document 981 1.1 tron encoding declaration. There are four built-in encodings: 982 1.1.1.6.4.1 perseant </p> 983 1.1 tron <ul> 984 1.1 tron <li>US-ASCII</li> 985 1.1 tron <li>UTF-8</li> 986 1.1 tron <li>UTF-16</li> 987 1.1 tron <li>ISO-8859-1</li> 988 1.1 tron </ul> 989 1.1.1.6.4.1 perseant <p> 990 1.1 tron Any other value will invoke a call to the UnknownEncodingHandler. 991 1.1.1.6.4.1 perseant </p> 992 1.1 tron </div> 993 1.1 tron 994 1.1.1.6 christos <h4 id="XML_ParserCreateNS">XML_ParserCreateNS</h4> 995 1.1.1.6 christos <pre class="fcndec"> 996 1.1 tron XML_Parser XMLCALL 997 1.1 tron XML_ParserCreateNS(const XML_Char *encoding, 998 1.1 tron XML_Char sep); 999 1.1 tron </pre> 1000 1.1 tron <div class="fcndef"> 1001 1.1 tron Constructs a new parser that has namespace processing in effect. Namespace 1002 1.1 tron expanded element names and attribute names are returned as a concatenation 1003 1.1 tron of the namespace URI, <em>sep</em>, and the local part of the name. This 1004 1.1.1.2 spz means that you should pick a character for <em>sep</em> that can't be part 1005 1.1.1.2 spz of an URI. Since Expat does not check namespace URIs for conformance, the 1006 1.1.1.2 spz only safe choice for a namespace separator is a character that is illegal 1007 1.1.1.2 spz in XML. For instance, <code>'\xFF'</code> is not legal in UTF-8, and 1008 1.1.1.2 spz <code>'\xFFFF'</code> is not legal in UTF-16. There is a special case when 1009 1.1.1.2 spz <em>sep</em> is the null character <code>'\0'</code>: the namespace URI and 1010 1.1.1.2 spz the local part will be concatenated without any separator - this is intended 1011 1.1.1.2 spz to support RDF processors. It is a programming error to use the null separator 1012 1.1.1.2 spz with <a href= "#XML_SetReturnNSTriplet">namespace triplets</a>.</div> 1013 1.1 tron 1014 1.1.1.6.4.1 perseant <p><strong>Note:</strong> 1015 1.1.1.6.4.1 perseant Expat does not validate namespace URIs (beyond encoding) 1016 1.1.1.6.4.1 perseant against RFC 3986 today (and is not required to do so with regard to 1017 1.1.1.6.4.1 perseant the XML 1.0 namespaces specification) but it may start doing that 1018 1.1.1.6.4.1 perseant in future releases. Before that, an application using Expat must 1019 1.1.1.6.4.1 perseant be ready to receive namespace URIs containing non-URI characters. 1020 1.1.1.6.4.1 perseant </p> 1021 1.1.1.6.4.1 perseant 1022 1.1.1.6 christos <h4 id="XML_ParserCreate_MM">XML_ParserCreate_MM</h4> 1023 1.1.1.6 christos <pre class="fcndec"> 1024 1.1 tron XML_Parser XMLCALL 1025 1.1 tron XML_ParserCreate_MM(const XML_Char *encoding, 1026 1.1 tron const XML_Memory_Handling_Suite *ms, 1027 1.1 tron const XML_Char *sep); 1028 1.1 tron </pre> 1029 1.1 tron <pre class="signature"> 1030 1.1 tron typedef struct { 1031 1.1 tron void *(XMLCALL *malloc_fcn)(size_t size); 1032 1.1 tron void *(XMLCALL *realloc_fcn)(void *ptr, size_t size); 1033 1.1 tron void (XMLCALL *free_fcn)(void *ptr); 1034 1.1 tron } XML_Memory_Handling_Suite; 1035 1.1 tron </pre> 1036 1.1 tron <div class="fcndef"> 1037 1.1 tron <p>Construct a new parser using the suite of memory handling functions 1038 1.1.1.6.4.1 perseant specified in <code>ms</code>. If <code>ms</code> is <code>NULL</code>, then use the 1039 1.1 tron standard set of memory management functions. If <code>sep</code> is 1040 1.1.1.6.4.1 perseant non-<code>NULL</code>, then namespace processing is enabled in the created parser 1041 1.1 tron and the character pointed at by sep is used as the separator between 1042 1.1 tron the namespace URI and the local part of the name.</p> 1043 1.1 tron </div> 1044 1.1 tron 1045 1.1.1.6 christos <h4 id="XML_ExternalEntityParserCreate">XML_ExternalEntityParserCreate</h4> 1046 1.1.1.6 christos <pre class="fcndec"> 1047 1.1 tron XML_Parser XMLCALL 1048 1.1 tron XML_ExternalEntityParserCreate(XML_Parser p, 1049 1.1 tron const XML_Char *context, 1050 1.1 tron const XML_Char *encoding); 1051 1.1 tron </pre> 1052 1.1 tron <div class="fcndef"> 1053 1.1 tron Construct a new <code>XML_Parser</code> object for parsing an external 1054 1.1 tron general entity. Context is the context argument passed in a call to a 1055 1.1 tron ExternalEntityRefHandler. Other state information such as handlers, 1056 1.1 tron user data, namespace processing is inherited from the parser passed as 1057 1.1 tron the 1st argument. So you shouldn't need to call any of the behavior 1058 1.1 tron changing functions on this parser (unless you want it to act 1059 1.1 tron differently than the parent parser). 1060 1.1 tron </div> 1061 1.1 tron 1062 1.1.1.6 christos <h4 id="XML_ParserFree">XML_ParserFree</h4> 1063 1.1.1.6 christos <pre class="fcndec"> 1064 1.1 tron void XMLCALL 1065 1.1 tron XML_ParserFree(XML_Parser p); 1066 1.1 tron </pre> 1067 1.1 tron <div class="fcndef"> 1068 1.1 tron Free memory used by the parser. Your application is responsible for 1069 1.1 tron freeing any memory associated with <a href="#userdata">user data</a>. 1070 1.1 tron </div> 1071 1.1 tron 1072 1.1.1.6 christos <h4 id="XML_ParserReset">XML_ParserReset</h4> 1073 1.1.1.6 christos <pre class="fcndec"> 1074 1.1 tron XML_Bool XMLCALL 1075 1.1 tron XML_ParserReset(XML_Parser p, 1076 1.1 tron const XML_Char *encoding); 1077 1.1 tron </pre> 1078 1.1 tron <div class="fcndef"> 1079 1.1 tron Clean up the memory structures maintained by the parser so that it may 1080 1.1 tron be used again. After this has been called, <code>parser</code> is 1081 1.1 tron ready to start parsing a new document. All handlers are cleared from 1082 1.1 tron the parser, except for the unknownEncodingHandler. The parser's external 1083 1.1 tron state is re-initialized except for the values of ns and ns_triplets. 1084 1.1 tron This function may not be used on a parser created using <code><a href= 1085 1.1 tron "#XML_ExternalEntityParserCreate" >XML_ExternalEntityParserCreate</a 1086 1.1 tron ></code>; it will return <code>XML_FALSE</code> in that case. Returns 1087 1.1 tron <code>XML_TRUE</code> on success. Your application is responsible for 1088 1.1 tron dealing with any memory associated with <a href="#userdata">user data</a>. 1089 1.1 tron </div> 1090 1.1 tron 1091 1.1 tron <h3><a name="parsing">Parsing</a></h3> 1092 1.1 tron 1093 1.1 tron <p>To state the obvious: the three parsing functions <code><a href= 1094 1.1 tron "#XML_Parse" >XML_Parse</a></code>, <code><a href= "#XML_ParseBuffer"> 1095 1.1 tron XML_ParseBuffer</a></code> and <code><a href= "#XML_GetBuffer"> 1096 1.1 tron XML_GetBuffer</a></code> must not be called from within a handler 1097 1.1 tron unless they operate on a separate parser instance, that is, one that 1098 1.1 tron did not call the handler. For example, it is OK to call the parsing 1099 1.1 tron functions from within an <code>XML_ExternalEntityRefHandler</code>, 1100 1.1 tron if they apply to the parser created by 1101 1.1 tron <code><a href= "#XML_ExternalEntityParserCreate" 1102 1.1 tron >XML_ExternalEntityParserCreate</a></code>.</p> 1103 1.1 tron 1104 1.1.1.6 christos <p>Note: The <code>len</code> argument passed to these functions 1105 1.1 tron should be considerably less than the maximum value for an integer, 1106 1.1 tron as it could create an integer overflow situation if the added 1107 1.1 tron lengths of a buffer and the unprocessed portion of the previous buffer 1108 1.1 tron exceed the maximum integer value. Input data at the end of a buffer 1109 1.1 tron will remain unprocessed if it is part of an XML token for which the 1110 1.1 tron end is not part of that buffer.</p> 1111 1.1 tron 1112 1.1.1.6.4.1 perseant <p><a name="isFinal"></a>The application <em>must</em> make a concluding 1113 1.1.1.6.4.1 perseant <code><a href="#XML_Parse">XML_Parse</a></code> or 1114 1.1.1.6.4.1 perseant <code><a href="#XML_ParseBuffer">XML_ParseBuffer</a></code> call 1115 1.1.1.6.4.1 perseant with <code>isFinal</code> set to <code>XML_TRUE</code>.</p> 1116 1.1.1.6.4.1 perseant 1117 1.1.1.6 christos <h4 id="XML_Parse">XML_Parse</h4> 1118 1.1.1.6 christos <pre class="fcndec"> 1119 1.1 tron enum XML_Status XMLCALL 1120 1.1 tron XML_Parse(XML_Parser p, 1121 1.1 tron const char *s, 1122 1.1 tron int len, 1123 1.1 tron int isFinal); 1124 1.1 tron </pre> 1125 1.1 tron <pre class="signature"> 1126 1.1 tron enum XML_Status { 1127 1.1 tron XML_STATUS_ERROR = 0, 1128 1.1 tron XML_STATUS_OK = 1 1129 1.1 tron }; 1130 1.1 tron </pre> 1131 1.1 tron <div class="fcndef"> 1132 1.1.1.6.4.1 perseant <p> 1133 1.1 tron Parse some more of the document. The string <code>s</code> is a buffer 1134 1.1 tron containing part (or perhaps all) of the document. The number of bytes of s 1135 1.1 tron that are part of the document is indicated by <code>len</code>. This means 1136 1.1.1.6.4.1 perseant that <code>s</code> doesn't have to be null-terminated. It also means that 1137 1.1 tron if <code>len</code> is larger than the number of bytes in the block of 1138 1.1.1.6.4.1 perseant memory that <code>s</code> points at, then a memory fault is likely. 1139 1.1.1.6.4.1 perseant Negative values for <code>len</code> are rejected since Expat 2.2.1. 1140 1.1.1.6.4.1 perseant The 1141 1.1 tron <code>isFinal</code> parameter informs the parser that this is the last 1142 1.1 tron piece of the document. Frequently, the last piece is empty (i.e. 1143 1.1 tron <code>len</code> is zero.) 1144 1.1.1.6.4.1 perseant </p> 1145 1.1.1.6.4.1 perseant 1146 1.1.1.6.4.1 perseant <p> 1147 1.1 tron If a parse error occurred, it returns <code>XML_STATUS_ERROR</code>. 1148 1.1 tron Otherwise it returns <code>XML_STATUS_OK</code> value. 1149 1.1.1.6.4.1 perseant Note that regardless of the return value, there is no guarantee that all 1150 1.1.1.6.4.1 perseant provided input has been parsed; only after <a href="#isFinal">the 1151 1.1.1.6.4.1 perseant concluding call</a> will all handler callbacks and parsing errors have 1152 1.1.1.6.4.1 perseant happened. 1153 1.1.1.6.4.1 perseant </p> 1154 1.1.1.6.4.1 perseant 1155 1.1.1.6.4.1 perseant <p> 1156 1.1.1.6.4.1 perseant Simplified, <code>XML_Parse</code> can be considered a convenience wrapper 1157 1.1.1.6.4.1 perseant that is pairing calls 1158 1.1.1.6.4.1 perseant to <code><a href="#XML_GetBuffer">XML_GetBuffer</a></code> 1159 1.1.1.6.4.1 perseant and <code><a href="#XML_ParseBuffer">XML_ParseBuffer</a></code> 1160 1.1.1.6.4.1 perseant (when Expat is built with macro <code>XML_CONTEXT_BYTES</code> 1161 1.1.1.6.4.1 perseant defined to a positive value, which is both common and default). 1162 1.1.1.6.4.1 perseant <code>XML_Parse</code> is then functionally equivalent to calling 1163 1.1.1.6.4.1 perseant <code><a href="#XML_GetBuffer">XML_GetBuffer</a></code>, 1164 1.1.1.6.4.1 perseant <code>memcpy</code>, and 1165 1.1.1.6.4.1 perseant <code><a href="#XML_ParseBuffer">XML_ParseBuffer</a></code>. 1166 1.1.1.6.4.1 perseant </p> 1167 1.1.1.6.4.1 perseant 1168 1.1.1.6.4.1 perseant <p> 1169 1.1.1.6.4.1 perseant To avoid double copying of the input, direct use of functions 1170 1.1.1.6.4.1 perseant <code><a href="#XML_GetBuffer">XML_GetBuffer</a></code> and 1171 1.1.1.6.4.1 perseant <code><a href="#XML_ParseBuffer">XML_ParseBuffer</a></code> is advised 1172 1.1.1.6.4.1 perseant for most production use, e.g. 1173 1.1.1.6.4.1 perseant if you're using <code>read</code> or similar functionality to fill your 1174 1.1.1.6.4.1 perseant buffers, fill directly into the buffer from 1175 1.1.1.6.4.1 perseant <code><a href="#XML_GetBuffer">XML_GetBuffer</a></code>, 1176 1.1.1.6.4.1 perseant then parse with <code><a href="#XML_ParseBuffer">XML_ParseBuffer</a></code>. 1177 1.1.1.6.4.1 perseant </p> 1178 1.1 tron </div> 1179 1.1 tron 1180 1.1.1.6 christos <h4 id="XML_ParseBuffer">XML_ParseBuffer</h4> 1181 1.1.1.6 christos <pre class="fcndec"> 1182 1.1 tron enum XML_Status XMLCALL 1183 1.1 tron XML_ParseBuffer(XML_Parser p, 1184 1.1 tron int len, 1185 1.1 tron int isFinal); 1186 1.1 tron </pre> 1187 1.1 tron <div class="fcndef"> 1188 1.1.1.6.4.1 perseant <p> 1189 1.1 tron This is just like <code><a href= "#XML_Parse" >XML_Parse</a></code>, 1190 1.1 tron except in this case Expat provides the buffer. By obtaining the 1191 1.1 tron buffer from Expat with the <code><a href= "#XML_GetBuffer" 1192 1.1 tron >XML_GetBuffer</a></code> function, the application can avoid double 1193 1.1 tron copying of the input. 1194 1.1.1.6.4.1 perseant </p> 1195 1.1.1.6.4.1 perseant 1196 1.1.1.6.4.1 perseant <p> 1197 1.1.1.6.4.1 perseant Negative values for <code>len</code> are rejected since Expat 2.6.3. 1198 1.1.1.6.4.1 perseant </p> 1199 1.1 tron </div> 1200 1.1 tron 1201 1.1.1.6 christos <h4 id="XML_GetBuffer">XML_GetBuffer</h4> 1202 1.1.1.6 christos <pre class="fcndec"> 1203 1.1 tron void * XMLCALL 1204 1.1 tron XML_GetBuffer(XML_Parser p, 1205 1.1 tron int len); 1206 1.1 tron </pre> 1207 1.1 tron <div class="fcndef"> 1208 1.1 tron Obtain a buffer of size <code>len</code> to read a piece of the document 1209 1.1.1.6.4.1 perseant into. A <code>NULL</code> value is returned if Expat can't allocate enough memory for 1210 1.1.1.6.4.1 perseant this buffer. A <code>NULL</code> value may also be returned if <code>len</code> is zero. 1211 1.1.1.6 christos This has to be called prior to every call to 1212 1.1 tron <code><a href= "#XML_ParseBuffer" >XML_ParseBuffer</a></code>. A 1213 1.1 tron typical use would look like this: 1214 1.1 tron 1215 1.1 tron <pre class="eg"> 1216 1.1 tron for (;;) { 1217 1.1 tron int bytes_read; 1218 1.1 tron void *buff = XML_GetBuffer(p, BUFF_SIZE); 1219 1.1 tron if (buff == NULL) { 1220 1.1 tron /* handle error */ 1221 1.1 tron } 1222 1.1 tron 1223 1.1 tron bytes_read = read(docfd, buff, BUFF_SIZE); 1224 1.1 tron if (bytes_read < 0) { 1225 1.1 tron /* handle error */ 1226 1.1 tron } 1227 1.1 tron 1228 1.1 tron if (! XML_ParseBuffer(p, bytes_read, bytes_read == 0)) { 1229 1.1 tron /* handle parse error */ 1230 1.1 tron } 1231 1.1 tron 1232 1.1 tron if (bytes_read == 0) 1233 1.1 tron break; 1234 1.1 tron } 1235 1.1 tron </pre> 1236 1.1 tron </div> 1237 1.1 tron 1238 1.1.1.6 christos <h4 id="XML_StopParser">XML_StopParser</h4> 1239 1.1.1.6 christos <pre class="fcndec"> 1240 1.1 tron enum XML_Status XMLCALL 1241 1.1 tron XML_StopParser(XML_Parser p, 1242 1.1 tron XML_Bool resumable); 1243 1.1 tron </pre> 1244 1.1 tron <div class="fcndef"> 1245 1.1 tron 1246 1.1 tron <p>Stops parsing, causing <code><a href= "#XML_Parse" 1247 1.1 tron >XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer" 1248 1.1 tron >XML_ParseBuffer</a></code> to return. Must be called from within a 1249 1.1 tron call-back handler, except when aborting (when <code>resumable</code> 1250 1.1 tron is <code>XML_FALSE</code>) an already suspended parser. Some 1251 1.1 tron call-backs may still follow because they would otherwise get 1252 1.1.1.6 christos lost, including</p> 1253 1.1 tron <ul> 1254 1.1 tron <li> the end element handler for empty elements when stopped in the 1255 1.1 tron start element handler,</li> 1256 1.1 tron <li> the end namespace declaration handler when stopped in the end 1257 1.1 tron element handler,</li> 1258 1.1 tron <li> the character data handler when stopped in the character data handler 1259 1.1 tron while making multiple call-backs on a contiguous chunk of characters,</li> 1260 1.1 tron </ul> 1261 1.1.1.6 christos <p>and possibly others.</p> 1262 1.1 tron 1263 1.1 tron <p>This can be called from most handlers, including DTD related 1264 1.1 tron call-backs, except when parsing an external parameter entity and 1265 1.1 tron <code>resumable</code> is <code>XML_TRUE</code>. Returns 1266 1.1 tron <code>XML_STATUS_OK</code> when successful, 1267 1.1 tron <code>XML_STATUS_ERROR</code> otherwise. The possible error codes 1268 1.1 tron are:</p> 1269 1.1 tron <dl> 1270 1.1.1.6.4.1 perseant <dt><code>XML_ERROR_NOT_STARTED</code></dt> 1271 1.1.1.6.4.1 perseant <dd> 1272 1.1.1.6.4.1 perseant when stopping or suspending a parser before it has started, 1273 1.1.1.6.4.1 perseant added in Expat 2.6.4. 1274 1.1.1.6.4.1 perseant </dd> 1275 1.1 tron <dt><code>XML_ERROR_SUSPENDED</code></dt> 1276 1.1 tron <dd>when suspending an already suspended parser.</dd> 1277 1.1 tron <dt><code>XML_ERROR_FINISHED</code></dt> 1278 1.1 tron <dd>when the parser has already finished.</dd> 1279 1.1 tron <dt><code>XML_ERROR_SUSPEND_PE</code></dt> 1280 1.1 tron <dd>when suspending while parsing an external PE.</dd> 1281 1.1 tron </dl> 1282 1.1 tron 1283 1.1 tron <p>Since the stop/resume feature requires application support in the 1284 1.1 tron outer parsing loop, it is an error to call this function for a parser 1285 1.1 tron not being handled appropriately; see <a href= "#stop-resume" 1286 1.1 tron >Temporarily Stopping Parsing</a> for more information.</p> 1287 1.1 tron 1288 1.1 tron <p>When <code>resumable</code> is <code>XML_TRUE</code> then parsing 1289 1.1 tron is <em>suspended</em>, that is, <code><a href= "#XML_Parse" 1290 1.1 tron >XML_Parse</a></code> and <code><a href= "#XML_ParseBuffer" 1291 1.1 tron >XML_ParseBuffer</a></code> return <code>XML_STATUS_SUSPENDED</code>. 1292 1.1 tron Otherwise, parsing is <em>aborted</em>, that is, <code><a href= 1293 1.1 tron "#XML_Parse" >XML_Parse</a></code> and <code><a href= 1294 1.1 tron "#XML_ParseBuffer" >XML_ParseBuffer</a></code> return 1295 1.1 tron <code>XML_STATUS_ERROR</code> with error code 1296 1.1 tron <code>XML_ERROR_ABORTED</code>.</p> 1297 1.1 tron 1298 1.1 tron <p><strong>Note:</strong> 1299 1.1 tron This will be applied to the current parser instance only, that is, if 1300 1.1 tron there is a parent parser then it will continue parsing when the 1301 1.1 tron external entity reference handler returns. It is up to the 1302 1.1 tron implementation of that handler to call <code><a href= 1303 1.1 tron "#XML_StopParser" >XML_StopParser</a></code> on the parent parser 1304 1.1 tron (recursively), if one wants to stop parsing altogether.</p> 1305 1.1 tron 1306 1.1 tron <p>When suspended, parsing can be resumed by calling <code><a href= 1307 1.1 tron "#XML_ResumeParser" >XML_ResumeParser</a></code>.</p> 1308 1.1 tron 1309 1.1 tron <p>New in Expat 1.95.8.</p> 1310 1.1 tron </div> 1311 1.1 tron 1312 1.1.1.6 christos <h4 id="XML_ResumeParser">XML_ResumeParser</h4> 1313 1.1.1.6 christos <pre class="fcndec"> 1314 1.1 tron enum XML_Status XMLCALL 1315 1.1 tron XML_ResumeParser(XML_Parser p); 1316 1.1 tron </pre> 1317 1.1 tron <div class="fcndef"> 1318 1.1 tron <p>Resumes parsing after it has been suspended with <code><a href= 1319 1.1 tron "#XML_StopParser" >XML_StopParser</a></code>. Must not be called from 1320 1.1 tron within a handler call-back. Returns same status codes as <code><a 1321 1.1 tron href= "#XML_Parse">XML_Parse</a></code> or <code><a href= 1322 1.1 tron "#XML_ParseBuffer" >XML_ParseBuffer</a></code>. An additional error 1323 1.1 tron code, <code>XML_ERROR_NOT_SUSPENDED</code>, will be returned if the 1324 1.1 tron parser was not currently suspended.</p> 1325 1.1 tron 1326 1.1 tron <p><strong>Note:</strong> 1327 1.1 tron This must be called on the most deeply nested child parser instance 1328 1.1 tron first, and on its parent parser only after the child parser has 1329 1.1 tron finished, to be applied recursively until the document entity's parser 1330 1.1 tron is restarted. That is, the parent parser will not resume by itself 1331 1.1 tron and it is up to the application to call <code><a href= 1332 1.1 tron "#XML_ResumeParser" >XML_ResumeParser</a></code> on it at the 1333 1.1 tron appropriate moment.</p> 1334 1.1 tron 1335 1.1 tron <p>New in Expat 1.95.8.</p> 1336 1.1 tron </div> 1337 1.1 tron 1338 1.1.1.6 christos <h4 id="XML_GetParsingStatus">XML_GetParsingStatus</h4> 1339 1.1.1.6 christos <pre class="fcndec"> 1340 1.1 tron void XMLCALL 1341 1.1 tron XML_GetParsingStatus(XML_Parser p, 1342 1.1 tron XML_ParsingStatus *status); 1343 1.1 tron </pre> 1344 1.1 tron <pre class="signature"> 1345 1.1 tron enum XML_Parsing { 1346 1.1 tron XML_INITIALIZED, 1347 1.1 tron XML_PARSING, 1348 1.1 tron XML_FINISHED, 1349 1.1 tron XML_SUSPENDED 1350 1.1 tron }; 1351 1.1 tron 1352 1.1 tron typedef struct { 1353 1.1 tron enum XML_Parsing parsing; 1354 1.1 tron XML_Bool finalBuffer; 1355 1.1 tron } XML_ParsingStatus; 1356 1.1 tron </pre> 1357 1.1 tron <div class="fcndef"> 1358 1.1 tron <p>Returns status of parser with respect to being initialized, 1359 1.1 tron parsing, finished, or suspended, and whether the final buffer is being 1360 1.1 tron processed. The <code>status</code> parameter <em>must not</em> be 1361 1.1.1.6.4.1 perseant <code>NULL</code>.</p> 1362 1.1 tron 1363 1.1 tron <p>New in Expat 1.95.8.</p> 1364 1.1 tron </div> 1365 1.1 tron 1366 1.1 tron 1367 1.1 tron <h3><a name="setting">Handler Setting</a></h3> 1368 1.1 tron 1369 1.1 tron <p>Although handlers are typically set prior to parsing and left alone, an 1370 1.1 tron application may choose to set or change the handler for a parsing event 1371 1.1 tron while the parse is in progress. For instance, your application may choose 1372 1.1 tron to ignore all text not descended from a <code>para</code> element. One 1373 1.1 tron way it could do this is to set the character handler when a para start tag 1374 1.1 tron is seen, and unset it for the corresponding end tag.</p> 1375 1.1 tron 1376 1.1.1.6.4.1 perseant <p>A handler may be <em>unset</em> by providing a <code>NULL</code> pointer to the 1377 1.1 tron appropriate handler setter. None of the handler setting functions have 1378 1.1 tron a return value.</p> 1379 1.1 tron 1380 1.1 tron <p>Your handlers will be receiving strings in arrays of type 1381 1.1 tron <code>XML_Char</code>. This type is conditionally defined in expat.h as 1382 1.1 tron either <code>char</code>, <code>wchar_t</code> or <code>unsigned short</code>. 1383 1.1 tron The former implies UTF-8 encoding, the latter two imply UTF-16 encoding. 1384 1.1 tron Note that you'll receive them in this form independent of the original 1385 1.1 tron encoding of the document.</p> 1386 1.1 tron 1387 1.1 tron <div class="handler"> 1388 1.1.1.6 christos <h4 id="XML_SetStartElementHandler">XML_SetStartElementHandler</h4> 1389 1.1.1.6 christos <pre class="setter"> 1390 1.1 tron void XMLCALL 1391 1.1 tron XML_SetStartElementHandler(XML_Parser p, 1392 1.1 tron XML_StartElementHandler start); 1393 1.1 tron </pre> 1394 1.1 tron <pre class="signature"> 1395 1.1 tron typedef void 1396 1.1 tron (XMLCALL *XML_StartElementHandler)(void *userData, 1397 1.1 tron const XML_Char *name, 1398 1.1 tron const XML_Char **atts); 1399 1.1 tron </pre> 1400 1.1 tron <p>Set handler for start (and empty) tags. Attributes are passed to the start 1401 1.1 tron handler as a pointer to a vector of char pointers. Each attribute seen in 1402 1.1 tron a start (or empty) tag occupies 2 consecutive places in this vector: the 1403 1.1 tron attribute name followed by the attribute value. These pairs are terminated 1404 1.1.1.6.4.1 perseant by a <code>NULL</code> pointer.</p> 1405 1.1 tron <p>Note that an empty tag generates a call to both start and end handlers 1406 1.1 tron (in that order).</p> 1407 1.1 tron </div> 1408 1.1 tron 1409 1.1 tron <div class="handler"> 1410 1.1.1.6 christos <h4 id="XML_SetEndElementHandler">XML_SetEndElementHandler</h4> 1411 1.1.1.6 christos <pre class="setter"> 1412 1.1 tron void XMLCALL 1413 1.1 tron XML_SetEndElementHandler(XML_Parser p, 1414 1.1 tron XML_EndElementHandler); 1415 1.1 tron </pre> 1416 1.1 tron <pre class="signature"> 1417 1.1 tron typedef void 1418 1.1 tron (XMLCALL *XML_EndElementHandler)(void *userData, 1419 1.1 tron const XML_Char *name); 1420 1.1 tron </pre> 1421 1.1 tron <p>Set handler for end (and empty) tags. As noted above, an empty tag 1422 1.1 tron generates a call to both start and end handlers.</p> 1423 1.1 tron </div> 1424 1.1 tron 1425 1.1 tron <div class="handler"> 1426 1.1.1.6 christos <h4 id="XML_SetElementHandler">XML_SetElementHandler</h4> 1427 1.1.1.6 christos <pre class="setter"> 1428 1.1 tron void XMLCALL 1429 1.1 tron XML_SetElementHandler(XML_Parser p, 1430 1.1 tron XML_StartElementHandler start, 1431 1.1 tron XML_EndElementHandler end); 1432 1.1 tron </pre> 1433 1.1 tron <p>Set handlers for start and end tags with one call.</p> 1434 1.1 tron </div> 1435 1.1 tron 1436 1.1 tron <div class="handler"> 1437 1.1.1.6 christos <h4 id="XML_SetCharacterDataHandler">XML_SetCharacterDataHandler</h4> 1438 1.1.1.6 christos <pre class="setter"> 1439 1.1 tron void XMLCALL 1440 1.1 tron XML_SetCharacterDataHandler(XML_Parser p, 1441 1.1 tron XML_CharacterDataHandler charhndl) 1442 1.1 tron </pre> 1443 1.1 tron <pre class="signature"> 1444 1.1 tron typedef void 1445 1.1 tron (XMLCALL *XML_CharacterDataHandler)(void *userData, 1446 1.1 tron const XML_Char *s, 1447 1.1 tron int len); 1448 1.1 tron </pre> 1449 1.1 tron <p>Set a text handler. The string your handler receives 1450 1.1.1.6 christos is <em>NOT null-terminated</em>. You have to use the length argument 1451 1.1 tron to deal with the end of the string. A single block of contiguous text 1452 1.1 tron free of markup may still result in a sequence of calls to this handler. 1453 1.1 tron In other words, if you're searching for a pattern in the text, it may 1454 1.1.1.6.4.1 perseant be split across calls to this handler. Note: Setting this handler to <code>NULL</code> 1455 1.1 tron may <em>NOT immediately</em> terminate call-backs if the parser is currently 1456 1.1 tron processing such a single block of contiguous markup-free text, as the parser 1457 1.1 tron will continue calling back until the end of the block is reached.</p> 1458 1.1 tron </div> 1459 1.1 tron 1460 1.1 tron <div class="handler"> 1461 1.1.1.6 christos <h4 id="XML_SetProcessingInstructionHandler">XML_SetProcessingInstructionHandler</h4> 1462 1.1.1.6 christos <pre class="setter"> 1463 1.1 tron void XMLCALL 1464 1.1 tron XML_SetProcessingInstructionHandler(XML_Parser p, 1465 1.1 tron XML_ProcessingInstructionHandler proc) 1466 1.1 tron </pre> 1467 1.1 tron <pre class="signature"> 1468 1.1 tron typedef void 1469 1.1 tron (XMLCALL *XML_ProcessingInstructionHandler)(void *userData, 1470 1.1 tron const XML_Char *target, 1471 1.1 tron const XML_Char *data); 1472 1.1 tron 1473 1.1 tron </pre> 1474 1.1 tron <p>Set a handler for processing instructions. The target is the first word 1475 1.1 tron in the processing instruction. The data is the rest of the characters in 1476 1.1 tron it after skipping all whitespace after the initial word.</p> 1477 1.1 tron </div> 1478 1.1 tron 1479 1.1 tron <div class="handler"> 1480 1.1.1.6 christos <h4 id="XML_SetCommentHandler">XML_SetCommentHandler</h4> 1481 1.1.1.6 christos <pre class="setter"> 1482 1.1 tron void XMLCALL 1483 1.1 tron XML_SetCommentHandler(XML_Parser p, 1484 1.1 tron XML_CommentHandler cmnt) 1485 1.1 tron </pre> 1486 1.1 tron <pre class="signature"> 1487 1.1 tron typedef void 1488 1.1 tron (XMLCALL *XML_CommentHandler)(void *userData, 1489 1.1 tron const XML_Char *data); 1490 1.1 tron </pre> 1491 1.1 tron <p>Set a handler for comments. The data is all text inside the comment 1492 1.1 tron delimiters.</p> 1493 1.1 tron </div> 1494 1.1 tron 1495 1.1 tron <div class="handler"> 1496 1.1.1.6 christos <h4 id="XML_SetStartCdataSectionHandler">XML_SetStartCdataSectionHandler</h4> 1497 1.1.1.6 christos <pre class="setter"> 1498 1.1 tron void XMLCALL 1499 1.1 tron XML_SetStartCdataSectionHandler(XML_Parser p, 1500 1.1 tron XML_StartCdataSectionHandler start); 1501 1.1 tron </pre> 1502 1.1 tron <pre class="signature"> 1503 1.1 tron typedef void 1504 1.1 tron (XMLCALL *XML_StartCdataSectionHandler)(void *userData); 1505 1.1 tron </pre> 1506 1.1 tron <p>Set a handler that gets called at the beginning of a CDATA section.</p> 1507 1.1 tron </div> 1508 1.1 tron 1509 1.1 tron <div class="handler"> 1510 1.1.1.6 christos <h4 id="XML_SetEndCdataSectionHandler">XML_SetEndCdataSectionHandler</h4> 1511 1.1.1.6 christos <pre class="setter"> 1512 1.1 tron void XMLCALL 1513 1.1 tron XML_SetEndCdataSectionHandler(XML_Parser p, 1514 1.1 tron XML_EndCdataSectionHandler end); 1515 1.1 tron </pre> 1516 1.1 tron <pre class="signature"> 1517 1.1 tron typedef void 1518 1.1 tron (XMLCALL *XML_EndCdataSectionHandler)(void *userData); 1519 1.1 tron </pre> 1520 1.1 tron <p>Set a handler that gets called at the end of a CDATA section.</p> 1521 1.1 tron </div> 1522 1.1 tron 1523 1.1 tron <div class="handler"> 1524 1.1.1.6 christos <h4 id="XML_SetCdataSectionHandler">XML_SetCdataSectionHandler</h4> 1525 1.1.1.6 christos <pre class="setter"> 1526 1.1 tron void XMLCALL 1527 1.1 tron XML_SetCdataSectionHandler(XML_Parser p, 1528 1.1 tron XML_StartCdataSectionHandler start, 1529 1.1 tron XML_EndCdataSectionHandler end) 1530 1.1 tron </pre> 1531 1.1 tron <p>Sets both CDATA section handlers with one call.</p> 1532 1.1 tron </div> 1533 1.1 tron 1534 1.1 tron <div class="handler"> 1535 1.1.1.6 christos <h4 id="XML_SetDefaultHandler">XML_SetDefaultHandler</h4> 1536 1.1.1.6 christos <pre class="setter"> 1537 1.1 tron void XMLCALL 1538 1.1 tron XML_SetDefaultHandler(XML_Parser p, 1539 1.1 tron XML_DefaultHandler hndl) 1540 1.1 tron </pre> 1541 1.1 tron <pre class="signature"> 1542 1.1 tron typedef void 1543 1.1 tron (XMLCALL *XML_DefaultHandler)(void *userData, 1544 1.1 tron const XML_Char *s, 1545 1.1 tron int len); 1546 1.1 tron </pre> 1547 1.1 tron 1548 1.1 tron <p>Sets a handler for any characters in the document which wouldn't 1549 1.1 tron otherwise be handled. This includes both data for which no handlers 1550 1.1 tron can be set (like some kinds of DTD declarations) and data which could 1551 1.1 tron be reported but which currently has no handler set. The characters 1552 1.1 tron are passed exactly as they were present in the XML document except 1553 1.1 tron that they will be encoded in UTF-8 or UTF-16. Line boundaries are not 1554 1.1 tron normalized. Note that a byte order mark character is not passed to the 1555 1.1 tron default handler. There are no guarantees about how characters are 1556 1.1 tron divided between calls to the default handler: for example, a comment 1557 1.1 tron might be split between multiple calls. Setting the handler with 1558 1.1 tron this call has the side effect of turning off expansion of references 1559 1.1 tron to internally defined general entities. Instead these references are 1560 1.1 tron passed to the default handler.</p> 1561 1.1 tron 1562 1.1 tron <p>See also <code><a 1563 1.1 tron href="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p> 1564 1.1 tron </div> 1565 1.1 tron 1566 1.1 tron <div class="handler"> 1567 1.1.1.6 christos <h4 id="XML_SetDefaultHandlerExpand">XML_SetDefaultHandlerExpand</h4> 1568 1.1.1.6 christos <pre class="setter"> 1569 1.1 tron void XMLCALL 1570 1.1 tron XML_SetDefaultHandlerExpand(XML_Parser p, 1571 1.1 tron XML_DefaultHandler hndl) 1572 1.1 tron </pre> 1573 1.1 tron <pre class="signature"> 1574 1.1 tron typedef void 1575 1.1 tron (XMLCALL *XML_DefaultHandler)(void *userData, 1576 1.1 tron const XML_Char *s, 1577 1.1 tron int len); 1578 1.1 tron </pre> 1579 1.1 tron <p>This sets a default handler, but doesn't inhibit the expansion of 1580 1.1 tron internal entity references. The entity reference will not be passed 1581 1.1 tron to the default handler.</p> 1582 1.1 tron 1583 1.1 tron <p>See also <code><a 1584 1.1 tron href="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p> 1585 1.1 tron </div> 1586 1.1 tron 1587 1.1 tron <div class="handler"> 1588 1.1.1.6 christos <h4 id="XML_SetExternalEntityRefHandler">XML_SetExternalEntityRefHandler</h4> 1589 1.1.1.6 christos <pre class="setter"> 1590 1.1 tron void XMLCALL 1591 1.1 tron XML_SetExternalEntityRefHandler(XML_Parser p, 1592 1.1 tron XML_ExternalEntityRefHandler hndl) 1593 1.1 tron </pre> 1594 1.1 tron <pre class="signature"> 1595 1.1 tron typedef int 1596 1.1 tron (XMLCALL *XML_ExternalEntityRefHandler)(XML_Parser p, 1597 1.1 tron const XML_Char *context, 1598 1.1 tron const XML_Char *base, 1599 1.1 tron const XML_Char *systemId, 1600 1.1 tron const XML_Char *publicId); 1601 1.1 tron </pre> 1602 1.1 tron <p>Set an external entity reference handler. This handler is also 1603 1.1 tron called for processing an external DTD subset if parameter entity parsing 1604 1.1 tron is in effect. (See <a href="#XML_SetParamEntityParsing"> 1605 1.1 tron <code>XML_SetParamEntityParsing</code></a>.)</p> 1606 1.1 tron 1607 1.1 tron <p>The <code>context</code> parameter specifies the parsing context in 1608 1.1 tron the format expected by the <code>context</code> argument to <code><a 1609 1.1 tron href="#XML_ExternalEntityParserCreate" 1610 1.1 tron >XML_ExternalEntityParserCreate</a></code>. <code>code</code> is 1611 1.1 tron valid only until the handler returns, so if the referenced entity is 1612 1.1.1.6.4.1 perseant to be parsed later, it must be copied. <code>context</code> is <code>NULL</code> 1613 1.1 tron only when the entity is a parameter entity, which is how one can 1614 1.1 tron differentiate between general and parameter entities.</p> 1615 1.1 tron 1616 1.1 tron <p>The <code>base</code> parameter is the base to use for relative 1617 1.1 tron system identifiers. It is set by <code><a 1618 1.1.1.6.4.1 perseant href="#XML_SetBase">XML_SetBase</a></code> and may be <code>NULL</code>. The 1619 1.1 tron <code>publicId</code> parameter is the public id given in the entity 1620 1.1.1.6.4.1 perseant declaration and may be <code>NULL</code>. <code>systemId</code> is the system 1621 1.1.1.6.4.1 perseant identifier specified in the entity declaration and is never <code>NULL</code>.</p> 1622 1.1 tron 1623 1.1 tron <p>There are a couple of ways in which this handler differs from 1624 1.1 tron others. First, this handler returns a status indicator (an 1625 1.1 tron integer). <code>XML_STATUS_OK</code> should be returned for successful 1626 1.1 tron handling of the external entity reference. Returning 1627 1.1 tron <code>XML_STATUS_ERROR</code> indicates failure, and causes the 1628 1.1 tron calling parser to return an 1629 1.1 tron <code>XML_ERROR_EXTERNAL_ENTITY_HANDLING</code> error.</p> 1630 1.1 tron 1631 1.1 tron <p>Second, instead of having the user data as its first argument, it 1632 1.1 tron receives the parser that encountered the entity reference. This, along 1633 1.1 tron with the context parameter, may be used as arguments to a call to 1634 1.1 tron <code><a href= "#XML_ExternalEntityParserCreate" 1635 1.1 tron >XML_ExternalEntityParserCreate</a></code>. Using the returned 1636 1.1 tron parser, the body of the external entity can be recursively parsed.</p> 1637 1.1 tron 1638 1.1 tron <p>Since this handler may be called recursively, it should not be saving 1639 1.1 tron information into global or static variables.</p> 1640 1.1 tron </div> 1641 1.1 tron 1642 1.1.1.6 christos <h4 id="XML_SetExternalEntityRefHandlerArg">XML_SetExternalEntityRefHandlerArg</h4> 1643 1.1.1.6 christos <pre class="fcndec"> 1644 1.1 tron void XMLCALL 1645 1.1 tron XML_SetExternalEntityRefHandlerArg(XML_Parser p, 1646 1.1 tron void *arg) 1647 1.1 tron </pre> 1648 1.1 tron <div class="fcndef"> 1649 1.1 tron <p>Set the argument passed to the ExternalEntityRefHandler. If 1650 1.1.1.6.4.1 perseant <code>arg</code> is not <code>NULL</code>, it is the new value passed to the 1651 1.1 tron handler set using <code><a href="#XML_SetExternalEntityRefHandler" 1652 1.1 tron >XML_SetExternalEntityRefHandler</a></code>; if <code>arg</code> is 1653 1.1.1.6.4.1 perseant <code>NULL</code>, the argument passed to the handler function will be the parser 1654 1.1 tron object itself.</p> 1655 1.1 tron 1656 1.1 tron <p><strong>Note:</strong> 1657 1.1 tron The type of <code>arg</code> and the type of the first argument to the 1658 1.1 tron ExternalEntityRefHandler do not match. This function takes a 1659 1.1 tron <code>void *</code> to be passed to the handler, while the handler 1660 1.1 tron accepts an <code>XML_Parser</code>. This is a historical accident, 1661 1.1 tron but will not be corrected before Expat 2.0 (at the earliest) to avoid 1662 1.1 tron causing compiler warnings for code that's known to work with this 1663 1.1 tron API. It is the responsibility of the application code to know the 1664 1.1 tron actual type of the argument passed to the handler and to manage it 1665 1.1 tron properly.</p> 1666 1.1 tron </div> 1667 1.1 tron 1668 1.1 tron <div class="handler"> 1669 1.1.1.6 christos <h4 id="XML_SetSkippedEntityHandler">XML_SetSkippedEntityHandler</h4> 1670 1.1.1.6 christos <pre class="setter"> 1671 1.1 tron void XMLCALL 1672 1.1 tron XML_SetSkippedEntityHandler(XML_Parser p, 1673 1.1 tron XML_SkippedEntityHandler handler) 1674 1.1 tron </pre> 1675 1.1 tron <pre class="signature"> 1676 1.1 tron typedef void 1677 1.1 tron (XMLCALL *XML_SkippedEntityHandler)(void *userData, 1678 1.1 tron const XML_Char *entityName, 1679 1.1 tron int is_parameter_entity); 1680 1.1 tron </pre> 1681 1.1 tron <p>Set a skipped entity handler. This is called in two situations:</p> 1682 1.1 tron <ol> 1683 1.1 tron <li>An entity reference is encountered for which no declaration 1684 1.1 tron has been read <em>and</em> this is not an error.</li> 1685 1.1 tron <li>An internal entity reference is read, but not expanded, because 1686 1.1 tron <a href="#XML_SetDefaultHandler"><code>XML_SetDefaultHandler</code></a> 1687 1.1 tron has been called.</li> 1688 1.1 tron </ol> 1689 1.1 tron <p>The <code>is_parameter_entity</code> argument will be non-zero for 1690 1.1.1.6 christos a parameter entity and zero for a general entity.</p> <p>Note: Skipped 1691 1.1 tron parameter entities in declarations and skipped general entities in 1692 1.1 tron attribute values cannot be reported, because the event would be out of 1693 1.1 tron sync with the reporting of the declarations or attribute values</p> 1694 1.1 tron </div> 1695 1.1 tron 1696 1.1 tron <div class="handler"> 1697 1.1.1.6 christos <h4 id="XML_SetUnknownEncodingHandler">XML_SetUnknownEncodingHandler</h4> 1698 1.1.1.6 christos <pre class="setter"> 1699 1.1 tron void XMLCALL 1700 1.1 tron XML_SetUnknownEncodingHandler(XML_Parser p, 1701 1.1 tron XML_UnknownEncodingHandler enchandler, 1702 1.1 tron void *encodingHandlerData) 1703 1.1 tron </pre> 1704 1.1 tron <pre class="signature"> 1705 1.1 tron typedef int 1706 1.1 tron (XMLCALL *XML_UnknownEncodingHandler)(void *encodingHandlerData, 1707 1.1 tron const XML_Char *name, 1708 1.1 tron XML_Encoding *info); 1709 1.1 tron 1710 1.1 tron typedef struct { 1711 1.1 tron int map[256]; 1712 1.1 tron void *data; 1713 1.1 tron int (XMLCALL *convert)(void *data, const char *s); 1714 1.1 tron void (XMLCALL *release)(void *data); 1715 1.1 tron } XML_Encoding; 1716 1.1 tron </pre> 1717 1.1 tron <p>Set a handler to deal with encodings other than the <a 1718 1.1 tron href="#builtin_encodings">built in set</a>. This should be done before 1719 1.1 tron <code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a href= 1720 1.1 tron "#XML_ParseBuffer" >XML_ParseBuffer</a></code> have been called on the 1721 1.1 tron given parser.</p> <p>If the handler knows how to deal with an encoding 1722 1.1 tron with the given name, it should fill in the <code>info</code> data 1723 1.1 tron structure and return <code>XML_STATUS_OK</code>. Otherwise it 1724 1.1 tron should return <code>XML_STATUS_ERROR</code>. The handler will be called 1725 1.1 tron at most once per parsed (external) entity. The optional application 1726 1.1 tron data pointer <code>encodingHandlerData</code> will be passed back to 1727 1.1 tron the handler.</p> 1728 1.1 tron 1729 1.1.1.5 maya <p>The map array contains information for every possible leading 1730 1.1 tron byte in a byte sequence. If the corresponding value is >= 0, then it's 1731 1.1 tron a single byte sequence and the byte encodes that Unicode value. If the 1732 1.1 tron value is -1, then that byte is invalid as the initial byte in a sequence. 1733 1.1 tron If the value is -n, where n is an integer > 1, then n is the number of 1734 1.1 tron bytes in the sequence and the actual conversion is accomplished by a 1735 1.1 tron call to the function pointed at by convert. This function may return -1 1736 1.1.1.6.4.1 perseant if the sequence itself is invalid. The convert pointer may be <code>NULL</code> if 1737 1.1 tron there are only single byte codes. The data parameter passed to the convert 1738 1.1 tron function is the data pointer from <code>XML_Encoding</code>. The 1739 1.1.1.6 christos string s is <em>NOT</em> null-terminated and points at the sequence of 1740 1.1 tron bytes to be converted.</p> 1741 1.1 tron 1742 1.1 tron <p>The function pointed at by <code>release</code> is called by the 1743 1.1.1.6.4.1 perseant parser when it is finished with the encoding. It may be <code>NULL</code>.</p> 1744 1.1 tron </div> 1745 1.1 tron 1746 1.1 tron <div class="handler"> 1747 1.1.1.6 christos <h4 id="XML_SetStartNamespaceDeclHandler">XML_SetStartNamespaceDeclHandler</h4> 1748 1.1.1.6 christos <pre class="setter"> 1749 1.1 tron void XMLCALL 1750 1.1 tron XML_SetStartNamespaceDeclHandler(XML_Parser p, 1751 1.1 tron XML_StartNamespaceDeclHandler start); 1752 1.1 tron </pre> 1753 1.1 tron <pre class="signature"> 1754 1.1 tron typedef void 1755 1.1 tron (XMLCALL *XML_StartNamespaceDeclHandler)(void *userData, 1756 1.1 tron const XML_Char *prefix, 1757 1.1 tron const XML_Char *uri); 1758 1.1 tron </pre> 1759 1.1 tron <p>Set a handler to be called when a namespace is declared. Namespace 1760 1.1 tron declarations occur inside start tags. But the namespace declaration start 1761 1.1 tron handler is called before the start tag handler for each namespace declared 1762 1.1 tron in that start tag.</p> 1763 1.1 tron </div> 1764 1.1 tron 1765 1.1 tron <div class="handler"> 1766 1.1.1.6 christos <h4 id="XML_SetEndNamespaceDeclHandler">XML_SetEndNamespaceDeclHandler</h4> 1767 1.1.1.6 christos <pre class="setter"> 1768 1.1 tron void XMLCALL 1769 1.1 tron XML_SetEndNamespaceDeclHandler(XML_Parser p, 1770 1.1 tron XML_EndNamespaceDeclHandler end); 1771 1.1 tron </pre> 1772 1.1 tron <pre class="signature"> 1773 1.1 tron typedef void 1774 1.1 tron (XMLCALL *XML_EndNamespaceDeclHandler)(void *userData, 1775 1.1 tron const XML_Char *prefix); 1776 1.1 tron </pre> 1777 1.1 tron <p>Set a handler to be called when leaving the scope of a namespace 1778 1.1 tron declaration. This will be called, for each namespace declaration, 1779 1.1 tron after the handler for the end tag of the element in which the 1780 1.1 tron namespace was declared.</p> 1781 1.1 tron </div> 1782 1.1 tron 1783 1.1 tron <div class="handler"> 1784 1.1.1.6 christos <h4 id="XML_SetNamespaceDeclHandler">XML_SetNamespaceDeclHandler</h4> 1785 1.1.1.6 christos <pre class="setter"> 1786 1.1 tron void XMLCALL 1787 1.1 tron XML_SetNamespaceDeclHandler(XML_Parser p, 1788 1.1 tron XML_StartNamespaceDeclHandler start, 1789 1.1 tron XML_EndNamespaceDeclHandler end) 1790 1.1 tron </pre> 1791 1.1 tron <p>Sets both namespace declaration handlers with a single call.</p> 1792 1.1 tron </div> 1793 1.1 tron 1794 1.1 tron <div class="handler"> 1795 1.1.1.6 christos <h4 id="XML_SetXmlDeclHandler">XML_SetXmlDeclHandler</h4> 1796 1.1.1.6 christos <pre class="setter"> 1797 1.1 tron void XMLCALL 1798 1.1 tron XML_SetXmlDeclHandler(XML_Parser p, 1799 1.1 tron XML_XmlDeclHandler xmldecl); 1800 1.1 tron </pre> 1801 1.1 tron <pre class="signature"> 1802 1.1 tron typedef void 1803 1.1 tron (XMLCALL *XML_XmlDeclHandler)(void *userData, 1804 1.1 tron const XML_Char *version, 1805 1.1 tron const XML_Char *encoding, 1806 1.1 tron int standalone); 1807 1.1 tron </pre> 1808 1.1 tron <p>Sets a handler that is called for XML declarations and also for 1809 1.1 tron text declarations discovered in external entities. The way to 1810 1.1.1.6.4.1 perseant distinguish is that the <code>version</code> parameter will be <code>NULL</code> 1811 1.1.1.6.4.1 perseant for text declarations. The <code>encoding</code> parameter may be <code>NULL</code> 1812 1.1 tron for an XML declaration. The <code>standalone</code> argument will 1813 1.1 tron contain -1, 0, or 1 indicating respectively that there was no 1814 1.1 tron standalone parameter in the declaration, that it was given as no, or 1815 1.1 tron that it was given as yes.</p> 1816 1.1 tron </div> 1817 1.1 tron 1818 1.1 tron <div class="handler"> 1819 1.1.1.6 christos <h4 id="XML_SetStartDoctypeDeclHandler">XML_SetStartDoctypeDeclHandler</h4> 1820 1.1.1.6 christos <pre class="setter"> 1821 1.1 tron void XMLCALL 1822 1.1 tron XML_SetStartDoctypeDeclHandler(XML_Parser p, 1823 1.1 tron XML_StartDoctypeDeclHandler start); 1824 1.1 tron </pre> 1825 1.1 tron <pre class="signature"> 1826 1.1 tron typedef void 1827 1.1 tron (XMLCALL *XML_StartDoctypeDeclHandler)(void *userData, 1828 1.1 tron const XML_Char *doctypeName, 1829 1.1 tron const XML_Char *sysid, 1830 1.1 tron const XML_Char *pubid, 1831 1.1 tron int has_internal_subset); 1832 1.1 tron </pre> 1833 1.1 tron <p>Set a handler that is called at the start of a DOCTYPE declaration, 1834 1.1 tron before any external or internal subset is parsed. Both <code>sysid</code> 1835 1.1.1.6.4.1 perseant and <code>pubid</code> may be <code>NULL</code>. The <code>has_internal_subset</code> 1836 1.1 tron will be non-zero if the DOCTYPE declaration has an internal subset.</p> 1837 1.1 tron </div> 1838 1.1 tron 1839 1.1 tron <div class="handler"> 1840 1.1.1.6 christos <h4 id="XML_SetEndDoctypeDeclHandler">XML_SetEndDoctypeDeclHandler</h4> 1841 1.1.1.6 christos <pre class="setter"> 1842 1.1 tron void XMLCALL 1843 1.1 tron XML_SetEndDoctypeDeclHandler(XML_Parser p, 1844 1.1 tron XML_EndDoctypeDeclHandler end); 1845 1.1 tron </pre> 1846 1.1 tron <pre class="signature"> 1847 1.1 tron typedef void 1848 1.1 tron (XMLCALL *XML_EndDoctypeDeclHandler)(void *userData); 1849 1.1 tron </pre> 1850 1.1 tron <p>Set a handler that is called at the end of a DOCTYPE declaration, 1851 1.1 tron after parsing any external subset.</p> 1852 1.1 tron </div> 1853 1.1 tron 1854 1.1 tron <div class="handler"> 1855 1.1.1.6 christos <h4 id="XML_SetDoctypeDeclHandler">XML_SetDoctypeDeclHandler</h4> 1856 1.1.1.6 christos <pre class="setter"> 1857 1.1 tron void XMLCALL 1858 1.1 tron XML_SetDoctypeDeclHandler(XML_Parser p, 1859 1.1 tron XML_StartDoctypeDeclHandler start, 1860 1.1 tron XML_EndDoctypeDeclHandler end); 1861 1.1 tron </pre> 1862 1.1 tron <p>Set both doctype handlers with one call.</p> 1863 1.1 tron </div> 1864 1.1 tron 1865 1.1 tron <div class="handler"> 1866 1.1.1.6 christos <h4 id="XML_SetElementDeclHandler">XML_SetElementDeclHandler</h4> 1867 1.1.1.6 christos <pre class="setter"> 1868 1.1 tron void XMLCALL 1869 1.1 tron XML_SetElementDeclHandler(XML_Parser p, 1870 1.1 tron XML_ElementDeclHandler eldecl); 1871 1.1 tron </pre> 1872 1.1 tron <pre class="signature"> 1873 1.1 tron typedef void 1874 1.1 tron (XMLCALL *XML_ElementDeclHandler)(void *userData, 1875 1.1 tron const XML_Char *name, 1876 1.1 tron XML_Content *model); 1877 1.1 tron </pre> 1878 1.1 tron <pre class="signature"> 1879 1.1 tron enum XML_Content_Type { 1880 1.1 tron XML_CTYPE_EMPTY = 1, 1881 1.1 tron XML_CTYPE_ANY, 1882 1.1 tron XML_CTYPE_MIXED, 1883 1.1 tron XML_CTYPE_NAME, 1884 1.1 tron XML_CTYPE_CHOICE, 1885 1.1 tron XML_CTYPE_SEQ 1886 1.1 tron }; 1887 1.1 tron 1888 1.1 tron enum XML_Content_Quant { 1889 1.1 tron XML_CQUANT_NONE, 1890 1.1 tron XML_CQUANT_OPT, 1891 1.1 tron XML_CQUANT_REP, 1892 1.1 tron XML_CQUANT_PLUS 1893 1.1 tron }; 1894 1.1 tron 1895 1.1 tron typedef struct XML_cp XML_Content; 1896 1.1 tron 1897 1.1 tron struct XML_cp { 1898 1.1 tron enum XML_Content_Type type; 1899 1.1 tron enum XML_Content_Quant quant; 1900 1.1 tron const XML_Char * name; 1901 1.1 tron unsigned int numchildren; 1902 1.1 tron XML_Content * children; 1903 1.1 tron }; 1904 1.1 tron </pre> 1905 1.1 tron <p>Sets a handler for element declarations in a DTD. The handler gets 1906 1.1 tron called with the name of the element in the declaration and a pointer 1907 1.1.1.6.4.1 perseant to a structure that contains the element model. It's the user code's 1908 1.1.1.6.4.1 perseant responsibility to free model when finished with it. See <code> 1909 1.1.1.6.4.1 perseant <a href="#XML_FreeContentModel">XML_FreeContentModel</a></code>. 1910 1.1.1.6.4.1 perseant There is no need to free the model from the handler, it can be kept 1911 1.1.1.6.4.1 perseant around and freed at a later stage.</p> 1912 1.1 tron 1913 1.1 tron <p>The <code>model</code> argument is the root of a tree of 1914 1.1 tron <code>XML_Content</code> nodes. If <code>type</code> equals 1915 1.1 tron <code>XML_CTYPE_EMPTY</code> or <code>XML_CTYPE_ANY</code>, then 1916 1.1 tron <code>quant</code> will be <code>XML_CQUANT_NONE</code>, and the other 1917 1.1.1.6.4.1 perseant fields will be zero or <code>NULL</code>. If <code>type</code> is 1918 1.1 tron <code>XML_CTYPE_MIXED</code>, then <code>quant</code> will be 1919 1.1 tron <code>XML_CQUANT_NONE</code> or <code>XML_CQUANT_REP</code> and 1920 1.1 tron <code>numchildren</code> will contain the number of elements that are 1921 1.1 tron allowed to be mixed in and <code>children</code> points to an array of 1922 1.1 tron <code>XML_Content</code> structures that will all have type 1923 1.1 tron XML_CTYPE_NAME with no quantification. Only the root node can be type 1924 1.1 tron <code>XML_CTYPE_EMPTY</code>, <code>XML_CTYPE_ANY</code>, or 1925 1.1 tron <code>XML_CTYPE_MIXED</code>.</p> 1926 1.1 tron 1927 1.1 tron <p>For type <code>XML_CTYPE_NAME</code>, the <code>name</code> field 1928 1.1 tron points to the name and the <code>numchildren</code> and 1929 1.1.1.6.4.1 perseant <code>children</code> fields will be zero and <code>NULL</code>. The 1930 1.1 tron <code>quant</code> field will indicate any quantifiers placed on the 1931 1.1 tron name.</p> 1932 1.1 tron 1933 1.1 tron <p>Types <code>XML_CTYPE_CHOICE</code> and <code>XML_CTYPE_SEQ</code> 1934 1.1 tron indicate a choice or sequence respectively. The 1935 1.1 tron <code>numchildren</code> field indicates how many nodes in the choice 1936 1.1 tron or sequence and <code>children</code> points to the nodes.</p> 1937 1.1 tron </div> 1938 1.1 tron 1939 1.1 tron <div class="handler"> 1940 1.1.1.6 christos <h4 id="XML_SetAttlistDeclHandler">XML_SetAttlistDeclHandler</h4> 1941 1.1.1.6 christos <pre class="setter"> 1942 1.1 tron void XMLCALL 1943 1.1 tron XML_SetAttlistDeclHandler(XML_Parser p, 1944 1.1 tron XML_AttlistDeclHandler attdecl); 1945 1.1 tron </pre> 1946 1.1 tron <pre class="signature"> 1947 1.1 tron typedef void 1948 1.1 tron (XMLCALL *XML_AttlistDeclHandler)(void *userData, 1949 1.1 tron const XML_Char *elname, 1950 1.1 tron const XML_Char *attname, 1951 1.1 tron const XML_Char *att_type, 1952 1.1 tron const XML_Char *dflt, 1953 1.1 tron int isrequired); 1954 1.1 tron </pre> 1955 1.1 tron <p>Set a handler for attlist declarations in the DTD. This handler is 1956 1.1 tron called for <em>each</em> attribute. So a single attlist declaration 1957 1.1 tron with multiple attributes declared will generate multiple calls to this 1958 1.1 tron handler. The <code>elname</code> parameter returns the name of the 1959 1.1 tron element for which the attribute is being declared. The attribute name 1960 1.1 tron is in the <code>attname</code> parameter. The attribute type is in the 1961 1.1 tron <code>att_type</code> parameter. It is the string representing the 1962 1.1 tron type in the declaration with whitespace removed.</p> 1963 1.1 tron 1964 1.1 tron <p>The <code>dflt</code> parameter holds the default value. It will be 1965 1.1.1.6.4.1 perseant <code>NULL</code> in the case of "#IMPLIED" or "#REQUIRED" attributes. You can 1966 1.1 tron distinguish these two cases by checking the <code>isrequired</code> 1967 1.1 tron parameter, which will be true in the case of "#REQUIRED" attributes. 1968 1.1 tron Attributes which are "#FIXED" will have also have a true 1969 1.1.1.6.4.1 perseant <code>isrequired</code>, but they will have the non-<code>NULL</code> fixed value 1970 1.1 tron in the <code>dflt</code> parameter.</p> 1971 1.1 tron </div> 1972 1.1 tron 1973 1.1 tron <div class="handler"> 1974 1.1.1.6 christos <h4 id="XML_SetEntityDeclHandler">XML_SetEntityDeclHandler</h4> 1975 1.1.1.6 christos <pre class="setter"> 1976 1.1 tron void XMLCALL 1977 1.1 tron XML_SetEntityDeclHandler(XML_Parser p, 1978 1.1 tron XML_EntityDeclHandler handler); 1979 1.1 tron </pre> 1980 1.1 tron <pre class="signature"> 1981 1.1 tron typedef void 1982 1.1 tron (XMLCALL *XML_EntityDeclHandler)(void *userData, 1983 1.1 tron const XML_Char *entityName, 1984 1.1 tron int is_parameter_entity, 1985 1.1 tron const XML_Char *value, 1986 1.1 tron int value_length, 1987 1.1 tron const XML_Char *base, 1988 1.1 tron const XML_Char *systemId, 1989 1.1 tron const XML_Char *publicId, 1990 1.1 tron const XML_Char *notationName); 1991 1.1 tron </pre> 1992 1.1 tron <p>Sets a handler that will be called for all entity declarations. 1993 1.1 tron The <code>is_parameter_entity</code> argument will be non-zero in the 1994 1.1 tron case of parameter entities and zero otherwise.</p> 1995 1.1 tron 1996 1.1 tron <p>For internal entities (<code><!ENTITY foo "bar"></code>), 1997 1.1.1.6.4.1 perseant <code>value</code> will be non-<code>NULL</code> and <code>systemId</code>, 1998 1.1.1.6.4.1 perseant <code>publicId</code>, and <code>notationName</code> will all be <code>NULL</code>. 1999 1.1.1.6.4.1 perseant The value string is <em>not</em> null-terminated; the length is 2000 1.1 tron provided in the <code>value_length</code> parameter. Do not use 2001 1.1 tron <code>value_length</code> to test for internal entities, since it is 2002 1.1 tron legal to have zero-length values. Instead check for whether or not 2003 1.1.1.6.4.1 perseant <code>value</code> is <code>NULL</code>.</p> <p>The <code>notationName</code> 2004 1.1.1.6.4.1 perseant argument will have a non-<code>NULL</code> value only for unparsed entity 2005 1.1 tron declarations.</p> 2006 1.1 tron </div> 2007 1.1 tron 2008 1.1 tron <div class="handler"> 2009 1.1.1.6 christos <h4 id="XML_SetUnparsedEntityDeclHandler">XML_SetUnparsedEntityDeclHandler</h4> 2010 1.1.1.6 christos <pre class="setter"> 2011 1.1 tron void XMLCALL 2012 1.1 tron XML_SetUnparsedEntityDeclHandler(XML_Parser p, 2013 1.1 tron XML_UnparsedEntityDeclHandler h) 2014 1.1 tron </pre> 2015 1.1 tron <pre class="signature"> 2016 1.1 tron typedef void 2017 1.1 tron (XMLCALL *XML_UnparsedEntityDeclHandler)(void *userData, 2018 1.1 tron const XML_Char *entityName, 2019 1.1 tron const XML_Char *base, 2020 1.1 tron const XML_Char *systemId, 2021 1.1 tron const XML_Char *publicId, 2022 1.1 tron const XML_Char *notationName); 2023 1.1 tron </pre> 2024 1.1 tron <p>Set a handler that receives declarations of unparsed entities. These 2025 1.1 tron are entity declarations that have a notation (NDATA) field:</p> 2026 1.1 tron 2027 1.1 tron <div id="eg"><pre> 2028 1.1 tron <!ENTITY logo SYSTEM "images/logo.gif" NDATA gif> 2029 1.1 tron </pre></div> 2030 1.1 tron <p>This handler is obsolete and is provided for backwards 2031 1.1 tron compatibility. Use instead <a href= "#XML_SetEntityDeclHandler" 2032 1.1 tron >XML_SetEntityDeclHandler</a>.</p> 2033 1.1 tron </div> 2034 1.1 tron 2035 1.1 tron <div class="handler"> 2036 1.1.1.6 christos <h4 id="XML_SetNotationDeclHandler">XML_SetNotationDeclHandler</h4> 2037 1.1.1.6 christos <pre class="setter"> 2038 1.1 tron void XMLCALL 2039 1.1 tron XML_SetNotationDeclHandler(XML_Parser p, 2040 1.1 tron XML_NotationDeclHandler h) 2041 1.1 tron </pre> 2042 1.1 tron <pre class="signature"> 2043 1.1 tron typedef void 2044 1.1 tron (XMLCALL *XML_NotationDeclHandler)(void *userData, 2045 1.1 tron const XML_Char *notationName, 2046 1.1 tron const XML_Char *base, 2047 1.1 tron const XML_Char *systemId, 2048 1.1 tron const XML_Char *publicId); 2049 1.1 tron </pre> 2050 1.1 tron <p>Set a handler that receives notation declarations.</p> 2051 1.1 tron </div> 2052 1.1 tron 2053 1.1 tron <div class="handler"> 2054 1.1.1.6 christos <h4 id="XML_SetNotStandaloneHandler">XML_SetNotStandaloneHandler</h4> 2055 1.1.1.6 christos <pre class="setter"> 2056 1.1 tron void XMLCALL 2057 1.1 tron XML_SetNotStandaloneHandler(XML_Parser p, 2058 1.1 tron XML_NotStandaloneHandler h) 2059 1.1 tron </pre> 2060 1.1 tron <pre class="signature"> 2061 1.1 tron typedef int 2062 1.1 tron (XMLCALL *XML_NotStandaloneHandler)(void *userData); 2063 1.1 tron </pre> 2064 1.1 tron <p>Set a handler that is called if the document is not "standalone". 2065 1.1 tron This happens when there is an external subset or a reference to a 2066 1.1 tron parameter entity, but does not have standalone set to "yes" in an XML 2067 1.1 tron declaration. If this handler returns <code>XML_STATUS_ERROR</code>, 2068 1.1 tron then the parser will throw an <code>XML_ERROR_NOT_STANDALONE</code> 2069 1.1 tron error.</p> 2070 1.1 tron </div> 2071 1.1 tron 2072 1.1 tron <h3><a name="position">Parse position and error reporting functions</a></h3> 2073 1.1 tron 2074 1.1 tron <p>These are the functions you'll want to call when the parse 2075 1.1 tron functions return <code>XML_STATUS_ERROR</code> (a parse error has 2076 1.1 tron occurred), although the position reporting functions are useful outside 2077 1.1 tron of errors. The position reported is the byte position (in the original 2078 1.1 tron document or entity encoding) of the first of the sequence of 2079 1.1 tron characters that generated the current event (or the error that caused 2080 1.1 tron the parse functions to return <code>XML_STATUS_ERROR</code>.) The 2081 1.1.1.6 christos exceptions are callbacks triggered by declarations in the document 2082 1.1 tron prologue, in which case they exact position reported is somewhere in the 2083 1.1 tron relevant markup, but not necessarily as meaningful as for other 2084 1.1 tron events.</p> 2085 1.1 tron 2086 1.1 tron <p>The position reporting functions are accurate only outside of the 2087 1.1 tron DTD. In other words, they usually return bogus information when 2088 1.1 tron called from within a DTD declaration handler.</p> 2089 1.1 tron 2090 1.1.1.6 christos <h4 id="XML_GetErrorCode">XML_GetErrorCode</h4> 2091 1.1.1.6 christos <pre class="fcndec"> 2092 1.1 tron enum XML_Error XMLCALL 2093 1.1 tron XML_GetErrorCode(XML_Parser p); 2094 1.1 tron </pre> 2095 1.1 tron <div class="fcndef"> 2096 1.1 tron Return what type of error has occurred. 2097 1.1 tron </div> 2098 1.1 tron 2099 1.1.1.6 christos <h4 id="XML_ErrorString">XML_ErrorString</h4> 2100 1.1.1.6 christos <pre class="fcndec"> 2101 1.1 tron const XML_LChar * XMLCALL 2102 1.1 tron XML_ErrorString(enum XML_Error code); 2103 1.1 tron </pre> 2104 1.1 tron <div class="fcndef"> 2105 1.1 tron Return a string describing the error corresponding to code. 2106 1.1 tron The code should be one of the enums that can be returned from 2107 1.1 tron <code><a href= "#XML_GetErrorCode" >XML_GetErrorCode</a></code>. 2108 1.1 tron </div> 2109 1.1 tron 2110 1.1.1.6 christos <h4 id="XML_GetCurrentByteIndex">XML_GetCurrentByteIndex</h4> 2111 1.1.1.6 christos <pre class="fcndec"> 2112 1.1 tron XML_Index XMLCALL 2113 1.1 tron XML_GetCurrentByteIndex(XML_Parser p); 2114 1.1 tron </pre> 2115 1.1 tron <div class="fcndef"> 2116 1.1 tron Return the byte offset of the position. This always corresponds to 2117 1.1 tron the values returned by <code><a href= "#XML_GetCurrentLineNumber" 2118 1.1 tron >XML_GetCurrentLineNumber</a></code> and <code><a href= 2119 1.1 tron "#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code>. 2120 1.1 tron </div> 2121 1.1 tron 2122 1.1.1.6 christos <h4 id="XML_GetCurrentLineNumber">XML_GetCurrentLineNumber</h4> 2123 1.1.1.6 christos <pre class="fcndec"> 2124 1.1 tron XML_Size XMLCALL 2125 1.1 tron XML_GetCurrentLineNumber(XML_Parser p); 2126 1.1 tron </pre> 2127 1.1 tron <div class="fcndef"> 2128 1.1 tron Return the line number of the position. The first line is reported as 2129 1.1 tron <code>1</code>. 2130 1.1 tron </div> 2131 1.1 tron 2132 1.1.1.6 christos <h4 id="XML_GetCurrentColumnNumber">XML_GetCurrentColumnNumber</h4> 2133 1.1.1.6 christos <pre class="fcndec"> 2134 1.1 tron XML_Size XMLCALL 2135 1.1 tron XML_GetCurrentColumnNumber(XML_Parser p); 2136 1.1 tron </pre> 2137 1.1 tron <div class="fcndef"> 2138 1.1 tron Return the offset, from the beginning of the current line, of 2139 1.1 tron the position. 2140 1.1 tron </div> 2141 1.1 tron 2142 1.1.1.6 christos <h4 id="XML_GetCurrentByteCount">XML_GetCurrentByteCount</h4> 2143 1.1.1.6 christos <pre class="fcndec"> 2144 1.1 tron int XMLCALL 2145 1.1 tron XML_GetCurrentByteCount(XML_Parser p); 2146 1.1 tron </pre> 2147 1.1 tron <div class="fcndef"> 2148 1.1 tron Return the number of bytes in the current event. Returns 2149 1.1 tron <code>0</code> if the event is inside a reference to an internal 2150 1.1 tron entity and for the end-tag event for empty element tags (the later can 2151 1.1 tron be used to distinguish empty-element tags from empty elements using 2152 1.1 tron separate start and end tags). 2153 1.1 tron </div> 2154 1.1 tron 2155 1.1.1.6 christos <h4 id="XML_GetInputContext">XML_GetInputContext</h4> 2156 1.1.1.6 christos <pre class="fcndec"> 2157 1.1 tron const char * XMLCALL 2158 1.1 tron XML_GetInputContext(XML_Parser p, 2159 1.1 tron int *offset, 2160 1.1 tron int *size); 2161 1.1 tron </pre> 2162 1.1 tron <div class="fcndef"> 2163 1.1 tron 2164 1.1 tron <p>Returns the parser's input buffer, sets the integer pointed at by 2165 1.1 tron <code>offset</code> to the offset within this buffer of the current 2166 1.1 tron parse position, and set the integer pointed at by <code>size</code> to 2167 1.1 tron the size of the returned buffer.</p> 2168 1.1 tron 2169 1.1 tron <p>This should only be called from within a handler during an active 2170 1.1 tron parse and the returned buffer should only be referred to from within 2171 1.1 tron the handler that made the call. This input buffer contains the 2172 1.1 tron untranslated bytes of the input.</p> 2173 1.1 tron 2174 1.1 tron <p>Only a limited amount of context is kept, so if the event 2175 1.1 tron triggering a call spans over a very large amount of input, the actual 2176 1.1 tron parse position may be before the beginning of the buffer.</p> 2177 1.1 tron 2178 1.1.1.6.4.1 perseant <p>If <code>XML_CONTEXT_BYTES</code> is zero, this will always 2179 1.1.1.6.4.1 perseant return <code>NULL</code>.</p> 2180 1.1 tron </div> 2181 1.1 tron 2182 1.1.1.6.4.1 perseant <h3><a name="attack-protection">Attack Protection</a><a name="billion-laughs"></a></h3> 2183 1.1.1.6 christos 2184 1.1.1.6 christos <h4 id="XML_SetBillionLaughsAttackProtectionMaximumAmplification">XML_SetBillionLaughsAttackProtectionMaximumAmplification</h4> 2185 1.1.1.6 christos <pre class="fcndec"> 2186 1.1.1.6 christos /* Added in Expat 2.4.0. */ 2187 1.1.1.6 christos XML_Bool XMLCALL 2188 1.1.1.6 christos XML_SetBillionLaughsAttackProtectionMaximumAmplification(XML_Parser p, 2189 1.1.1.6 christos float maximumAmplificationFactor); 2190 1.1.1.6 christos </pre> 2191 1.1.1.6 christos <div class="fcndef"> 2192 1.1.1.6 christos <p> 2193 1.1.1.6 christos Sets the maximum tolerated amplification factor 2194 1.1.1.6 christos for protection against 2195 1.1.1.6 christos <a href="https://en.wikipedia.org/wiki/Billion_laughs_attack">billion laughs attacks</a> 2196 1.1.1.6 christos (default: <code>100.0</code>) 2197 1.1.1.6 christos of parser <code>p</code> to <code>maximumAmplificationFactor</code>, and 2198 1.1.1.6 christos returns <code>XML_TRUE</code> upon success and <code>XML_FALSE</code> upon error. 2199 1.1.1.6 christos </p> 2200 1.1.1.6 christos 2201 1.1.1.6 christos The amplification factor is calculated as .. 2202 1.1.1.6 christos <pre> 2203 1.1.1.6 christos amplification := (direct + indirect) / direct 2204 1.1.1.6 christos </pre> 2205 1.1.1.6 christos .. while parsing, whereas 2206 1.1.1.6 christos <code>direct</code> is the number of bytes read from the primary document in parsing and 2207 1.1.1.6 christos <code>indirect</code> is the number of bytes added by expanding entities and reading of external DTD files, combined. 2208 1.1.1.6 christos 2209 1.1.1.6 christos <p>For a call to <code>XML_SetBillionLaughsAttackProtectionMaximumAmplification</code> to succeed:</p> 2210 1.1.1.6 christos <ul> 2211 1.1.1.6 christos <li>parser <code>p</code> must be a non-<code>NULL</code> root parser (without any parent parsers) and</li> 2212 1.1.1.6 christos <li><code>maximumAmplificationFactor</code> must be non-<code>NaN</code> and greater than or equal to <code>1.0</code>.</li> 2213 1.1.1.6 christos </ul> 2214 1.1.1.6 christos 2215 1.1.1.6 christos <p> 2216 1.1.1.6 christos <strong>Note:</strong> 2217 1.1.1.6 christos If you ever need to increase this value for non-attack payload, 2218 1.1.1.6 christos please <a href="https://github.com/libexpat/libexpat/issues">file a bug report</a>. 2219 1.1.1.6 christos </p> 2220 1.1.1.6 christos 2221 1.1.1.6 christos <p> 2222 1.1.1.6 christos <strong>Note:</strong> 2223 1.1.1.6 christos Peak amplifications 2224 1.1.1.6 christos of factor 15,000 for the entire payload and 2225 1.1.1.6 christos of factor 30,000 in the middle of parsing 2226 1.1.1.6 christos have been observed with small benign files in practice. 2227 1.1.1.6 christos 2228 1.1.1.6 christos So if you do reduce the maximum allowed amplification, 2229 1.1.1.6 christos please make sure that the activation threshold is still big enough 2230 1.1.1.6 christos to not end up with undesired false positives (i.e. benign files being rejected). 2231 1.1.1.6 christos </p> 2232 1.1.1.6 christos </div> 2233 1.1.1.6 christos 2234 1.1.1.6 christos <h4 id="XML_SetBillionLaughsAttackProtectionActivationThreshold">XML_SetBillionLaughsAttackProtectionActivationThreshold</h4> 2235 1.1.1.6 christos <pre class="fcndec"> 2236 1.1.1.6 christos /* Added in Expat 2.4.0. */ 2237 1.1.1.6 christos XML_Bool XMLCALL 2238 1.1.1.6 christos XML_SetBillionLaughsAttackProtectionActivationThreshold(XML_Parser p, 2239 1.1.1.6 christos unsigned long long activationThresholdBytes); 2240 1.1.1.6 christos </pre> 2241 1.1.1.6 christos <div class="fcndef"> 2242 1.1.1.6 christos <p> 2243 1.1.1.6 christos Sets number of output bytes (including amplification from entity expansion and reading DTD files) 2244 1.1.1.6 christos needed to activate protection against 2245 1.1.1.6 christos <a href="https://en.wikipedia.org/wiki/Billion_laughs_attack">billion laughs attacks</a> 2246 1.1.1.6 christos (default: <code>8 MiB</code>) 2247 1.1.1.6 christos of parser <code>p</code> to <code>activationThresholdBytes</code>, and 2248 1.1.1.6 christos returns <code>XML_TRUE</code> upon success and <code>XML_FALSE</code> upon error. 2249 1.1.1.6 christos </p> 2250 1.1.1.6 christos 2251 1.1.1.6 christos <p>For a call to <code>XML_SetBillionLaughsAttackProtectionActivationThreshold</code> to succeed:</p> 2252 1.1.1.6 christos <ul> 2253 1.1.1.6 christos <li>parser <code>p</code> must be a non-<code>NULL</code> root parser (without any parent parsers).</li> 2254 1.1.1.6 christos </ul> 2255 1.1.1.6 christos 2256 1.1.1.6 christos <p> 2257 1.1.1.6 christos <strong>Note:</strong> 2258 1.1.1.6 christos If you ever need to increase this value for non-attack payload, 2259 1.1.1.6 christos please <a href="https://github.com/libexpat/libexpat/issues">file a bug report</a>. 2260 1.1.1.6 christos </p> 2261 1.1.1.6 christos 2262 1.1.1.6 christos <p> 2263 1.1.1.6 christos <strong>Note:</strong> 2264 1.1.1.6 christos Activation thresholds below 4 MiB are known to break support for 2265 1.1.1.6 christos <a href="https://en.wikipedia.org/wiki/Darwin_Information_Typing_Architecture">DITA</a> 1.3 payload 2266 1.1.1.6 christos and are hence not recommended. 2267 1.1.1.6 christos </p> 2268 1.1.1.6 christos </div> 2269 1.1.1.6 christos 2270 1.1.1.6.4.1 perseant <h4 id="XML_SetReparseDeferralEnabled">XML_SetReparseDeferralEnabled</h4> 2271 1.1.1.6.4.1 perseant <pre class="fcndec"> 2272 1.1.1.6.4.1 perseant /* Added in Expat 2.6.0. */ 2273 1.1.1.6.4.1 perseant XML_Bool XMLCALL 2274 1.1.1.6.4.1 perseant XML_SetReparseDeferralEnabled(XML_Parser parser, XML_Bool enabled); 2275 1.1.1.6.4.1 perseant </pre> 2276 1.1.1.6.4.1 perseant <div class="fcndef"> 2277 1.1.1.6.4.1 perseant <p> 2278 1.1.1.6.4.1 perseant Large tokens may require many parse calls before enough data is available for Expat to parse it in full. 2279 1.1.1.6.4.1 perseant If Expat retried parsing the token on every parse call, parsing could take quadratic time. 2280 1.1.1.6.4.1 perseant To avoid this, Expat only retries once a significant amount of new data is available. 2281 1.1.1.6.4.1 perseant This function allows disabling this behavior. 2282 1.1.1.6.4.1 perseant </p> 2283 1.1.1.6.4.1 perseant <p> 2284 1.1.1.6.4.1 perseant The <code>enabled</code> argument should be <code>XML_TRUE</code> or <code>XML_FALSE</code>. 2285 1.1.1.6.4.1 perseant </p> 2286 1.1.1.6.4.1 perseant <p> 2287 1.1.1.6.4.1 perseant Returns <code>XML_TRUE</code> on success, and <code>XML_FALSE</code> on error. 2288 1.1.1.6.4.1 perseant </p> 2289 1.1.1.6.4.1 perseant </div> 2290 1.1.1.6.4.1 perseant 2291 1.1 tron <h3><a name="miscellaneous">Miscellaneous functions</a></h3> 2292 1.1 tron 2293 1.1 tron <p>The functions in this section either obtain state information from 2294 1.1.1.5 maya the parser or can be used to dynamically set parser options.</p> 2295 1.1 tron 2296 1.1.1.6 christos <h4 id="XML_SetUserData">XML_SetUserData</h4> 2297 1.1.1.6 christos <pre class="fcndec"> 2298 1.1 tron void XMLCALL 2299 1.1 tron XML_SetUserData(XML_Parser p, 2300 1.1 tron void *userData); 2301 1.1 tron </pre> 2302 1.1 tron <div class="fcndef"> 2303 1.1 tron This sets the user data pointer that gets passed to handlers. It 2304 1.1 tron overwrites any previous value for this pointer. Note that the 2305 1.1 tron application is responsible for freeing the memory associated with 2306 1.1 tron <code>userData</code> when it is finished with the parser. So if you 2307 1.1 tron call this when there's already a pointer there, and you haven't freed 2308 1.1 tron the memory associated with it, then you've probably just leaked 2309 1.1 tron memory. 2310 1.1 tron </div> 2311 1.1 tron 2312 1.1.1.6 christos <h4 id="XML_GetUserData">XML_GetUserData</h4> 2313 1.1.1.6 christos <pre class="fcndec"> 2314 1.1 tron void * XMLCALL 2315 1.1 tron XML_GetUserData(XML_Parser p); 2316 1.1 tron </pre> 2317 1.1 tron <div class="fcndef"> 2318 1.1 tron This returns the user data pointer that gets passed to handlers. 2319 1.1 tron It is actually implemented as a macro. 2320 1.1 tron </div> 2321 1.1 tron 2322 1.1.1.6 christos <h4 id="XML_UseParserAsHandlerArg">XML_UseParserAsHandlerArg</h4> 2323 1.1.1.6 christos <pre class="fcndec"> 2324 1.1 tron void XMLCALL 2325 1.1 tron XML_UseParserAsHandlerArg(XML_Parser p); 2326 1.1 tron </pre> 2327 1.1 tron <div class="fcndef"> 2328 1.1 tron After this is called, handlers receive the parser in their 2329 1.1 tron <code>userData</code> arguments. The user data can still be obtained 2330 1.1 tron using the <code><a href= "#XML_GetUserData" 2331 1.1 tron >XML_GetUserData</a></code> function. 2332 1.1 tron </div> 2333 1.1 tron 2334 1.1.1.6 christos <h4 id="XML_SetBase">XML_SetBase</h4> 2335 1.1.1.6 christos <pre class="fcndec"> 2336 1.1 tron enum XML_Status XMLCALL 2337 1.1 tron XML_SetBase(XML_Parser p, 2338 1.1 tron const XML_Char *base); 2339 1.1 tron </pre> 2340 1.1 tron <div class="fcndef"> 2341 1.1 tron Set the base to be used for resolving relative URIs in system 2342 1.1 tron identifiers. The return value is <code>XML_STATUS_ERROR</code> if 2343 1.1 tron there's no memory to store base, otherwise it's 2344 1.1 tron <code>XML_STATUS_OK</code>. 2345 1.1 tron </div> 2346 1.1 tron 2347 1.1.1.6 christos <h4 id="XML_GetBase">XML_GetBase</h4> 2348 1.1.1.6 christos <pre class="fcndec"> 2349 1.1 tron const XML_Char * XMLCALL 2350 1.1 tron XML_GetBase(XML_Parser p); 2351 1.1 tron </pre> 2352 1.1 tron <div class="fcndef"> 2353 1.1 tron Return the base for resolving relative URIs. 2354 1.1 tron </div> 2355 1.1 tron 2356 1.1.1.6 christos <h4 id="XML_GetSpecifiedAttributeCount">XML_GetSpecifiedAttributeCount</h4> 2357 1.1.1.6 christos <pre class="fcndec"> 2358 1.1 tron int XMLCALL 2359 1.1 tron XML_GetSpecifiedAttributeCount(XML_Parser p); 2360 1.1 tron </pre> 2361 1.1 tron <div class="fcndef"> 2362 1.1 tron When attributes are reported to the start handler in the atts vector, 2363 1.1 tron attributes that were explicitly set in the element occur before any 2364 1.1 tron attributes that receive their value from default information in an 2365 1.1 tron ATTLIST declaration. This function returns the number of attributes 2366 1.1 tron that were explicitly set times two, thus giving the offset in the 2367 1.1 tron <code>atts</code> array passed to the start tag handler of the first 2368 1.1 tron attribute set due to defaults. It supplies information for the last 2369 1.1 tron call to a start handler. If called inside a start handler, then that 2370 1.1 tron means the current call. 2371 1.1 tron </div> 2372 1.1 tron 2373 1.1.1.6 christos <h4 id="XML_GetIdAttributeIndex">XML_GetIdAttributeIndex</h4> 2374 1.1.1.6 christos <pre class="fcndec"> 2375 1.1 tron int XMLCALL 2376 1.1 tron XML_GetIdAttributeIndex(XML_Parser p); 2377 1.1 tron </pre> 2378 1.1 tron <div class="fcndef"> 2379 1.1 tron Returns the index of the ID attribute passed in the atts array in the 2380 1.1 tron last call to <code><a href= "#XML_StartElementHandler" 2381 1.1 tron >XML_StartElementHandler</a></code>, or -1 if there is no ID 2382 1.1 tron attribute. If called inside a start handler, then that means the 2383 1.1 tron current call. 2384 1.1 tron </div> 2385 1.1 tron 2386 1.1.1.6 christos <h4 id="XML_GetAttributeInfo">XML_GetAttributeInfo</h4> 2387 1.1.1.6 christos <pre class="fcndec"> 2388 1.1.1.2 spz const XML_AttrInfo * XMLCALL 2389 1.1.1.2 spz XML_GetAttributeInfo(XML_Parser parser); 2390 1.1.1.2 spz </pre> 2391 1.1.1.2 spz <pre class="signature"> 2392 1.1.1.2 spz typedef struct { 2393 1.1.1.2 spz XML_Index nameStart; /* Offset to beginning of the attribute name. */ 2394 1.1.1.2 spz XML_Index nameEnd; /* Offset after the attribute name's last byte. */ 2395 1.1.1.2 spz XML_Index valueStart; /* Offset to beginning of the attribute value. */ 2396 1.1.1.2 spz XML_Index valueEnd; /* Offset after the attribute value's last byte. */ 2397 1.1.1.2 spz } XML_AttrInfo; 2398 1.1.1.2 spz </pre> 2399 1.1.1.2 spz <div class="fcndef"> 2400 1.1.1.2 spz Returns an array of <code>XML_AttrInfo</code> structures for the 2401 1.1.1.2 spz attribute/value pairs passed in the last call to the 2402 1.1.1.2 spz <code>XML_StartElementHandler</code> that were specified 2403 1.1.1.2 spz in the start-tag rather than defaulted. Each attribute/value pair counts 2404 1.1.1.2 spz as 1; thus the number of entries in the array is 2405 1.1.1.2 spz <code>XML_GetSpecifiedAttributeCount(parser) / 2</code>. 2406 1.1.1.2 spz </div> 2407 1.1.1.2 spz 2408 1.1.1.6 christos <h4 id="XML_SetEncoding">XML_SetEncoding</h4> 2409 1.1.1.6 christos <pre class="fcndec"> 2410 1.1 tron enum XML_Status XMLCALL 2411 1.1 tron XML_SetEncoding(XML_Parser p, 2412 1.1 tron const XML_Char *encoding); 2413 1.1 tron </pre> 2414 1.1 tron <div class="fcndef"> 2415 1.1 tron Set the encoding to be used by the parser. It is equivalent to 2416 1.1.1.6.4.1 perseant passing a non-<code>NULL</code> encoding argument to the parser creation functions. 2417 1.1 tron It must not be called after <code><a href= "#XML_Parse" 2418 1.1 tron >XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer" 2419 1.1 tron >XML_ParseBuffer</a></code> have been called on the given parser. 2420 1.1 tron Returns <code>XML_STATUS_OK</code> on success or 2421 1.1 tron <code>XML_STATUS_ERROR</code> on error. 2422 1.1 tron </div> 2423 1.1 tron 2424 1.1.1.6 christos <h4 id="XML_SetParamEntityParsing">XML_SetParamEntityParsing</h4> 2425 1.1.1.6 christos <pre class="fcndec"> 2426 1.1 tron int XMLCALL 2427 1.1 tron XML_SetParamEntityParsing(XML_Parser p, 2428 1.1 tron enum XML_ParamEntityParsing code); 2429 1.1 tron </pre> 2430 1.1 tron <div class="fcndef"> 2431 1.1 tron This enables parsing of parameter entities, including the external 2432 1.1 tron parameter entity that is the external DTD subset, according to 2433 1.1 tron <code>code</code>. 2434 1.1 tron The choices for <code>code</code> are: 2435 1.1 tron <ul> 2436 1.1 tron <li><code>XML_PARAM_ENTITY_PARSING_NEVER</code></li> 2437 1.1 tron <li><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></li> 2438 1.1 tron <li><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></li> 2439 1.1 tron </ul> 2440 1.1.1.2 spz <b>Note:</b> If <code>XML_SetParamEntityParsing</code> is called after 2441 1.1.1.2 spz <code>XML_Parse</code> or <code>XML_ParseBuffer</code>, then it has 2442 1.1.1.2 spz no effect and will always return 0. 2443 1.1.1.2 spz </div> 2444 1.1.1.2 spz 2445 1.1.1.6 christos <h4 id="XML_SetHashSalt">XML_SetHashSalt</h4> 2446 1.1.1.6 christos <pre class="fcndec"> 2447 1.1.1.2 spz int XMLCALL 2448 1.1.1.2 spz XML_SetHashSalt(XML_Parser p, 2449 1.1.1.2 spz unsigned long hash_salt); 2450 1.1.1.2 spz </pre> 2451 1.1.1.2 spz <div class="fcndef"> 2452 1.1.1.2 spz Sets the hash salt to use for internal hash calculations. 2453 1.1.1.2 spz Helps in preventing DoS attacks based on predicting hash 2454 1.1.1.2 spz function behavior. In order to have an effect this must be called 2455 1.1.1.2 spz before parsing has started. Returns 1 if successful, 0 when called 2456 1.1.1.2 spz after <code>XML_Parse</code> or <code>XML_ParseBuffer</code>. 2457 1.1.1.6 christos <p><b>Note:</b> This call is optional, as the parser will auto-generate 2458 1.1.1.5 maya a new random salt value if no value has been set at the start of parsing.</p> 2459 1.1.1.6 christos <p><b>Note:</b> One should not call <code>XML_SetHashSalt</code> with a 2460 1.1.1.3 spz hash salt value of 0, as this value is used as sentinel value to indicate 2461 1.1.1.3 spz that <code>XML_SetHashSalt</code> has <b>not</b> been called. Consequently 2462 1.1.1.3 spz such a call will have no effect, even if it returns 1.</p> 2463 1.1 tron </div> 2464 1.1 tron 2465 1.1.1.6 christos <h4 id="XML_UseForeignDTD">XML_UseForeignDTD</h4> 2466 1.1.1.6 christos <pre class="fcndec"> 2467 1.1 tron enum XML_Error XMLCALL 2468 1.1 tron XML_UseForeignDTD(XML_Parser parser, XML_Bool useDTD); 2469 1.1 tron </pre> 2470 1.1 tron <div class="fcndef"> 2471 1.1 tron <p>This function allows an application to provide an external subset 2472 1.1 tron for the document type declaration for documents which do not specify 2473 1.1 tron an external subset of their own. For documents which specify an 2474 1.1 tron external subset in their DOCTYPE declaration, the application-provided 2475 1.1 tron subset will be ignored. If the document does not contain a DOCTYPE 2476 1.1 tron declaration at all and <code>useDTD</code> is true, the 2477 1.1 tron application-provided subset will be parsed, but the 2478 1.1 tron <code>startDoctypeDeclHandler</code> and 2479 1.1 tron <code>endDoctypeDeclHandler</code> functions, if set, will not be 2480 1.1 tron called. The setting of parameter entity parsing, controlled using 2481 1.1 tron <code><a href= "#XML_SetParamEntityParsing" 2482 1.1 tron >XML_SetParamEntityParsing</a></code>, will be honored.</p> 2483 1.1 tron 2484 1.1 tron <p>The application-provided external subset is read by calling the 2485 1.1 tron external entity reference handler set via <code><a href= 2486 1.1 tron "#XML_SetExternalEntityRefHandler" 2487 1.1 tron >XML_SetExternalEntityRefHandler</a></code> with both 2488 1.1.1.6.4.1 perseant <code>publicId</code> and <code>systemId</code> set to <code>NULL</code>.</p> 2489 1.1 tron 2490 1.1 tron <p>If this function is called after parsing has begun, it returns 2491 1.1 tron <code>XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING</code> and ignores 2492 1.1 tron <code>useDTD</code>. If called when Expat has been compiled without 2493 1.1 tron DTD support, it returns 2494 1.1 tron <code>XML_ERROR_FEATURE_REQUIRES_XML_DTD</code>. Otherwise, it 2495 1.1 tron returns <code>XML_ERROR_NONE</code>.</p> 2496 1.1 tron 2497 1.1 tron <p><b>Note:</b> For the purpose of checking WFC: Entity Declared, passing 2498 1.1 tron <code>useDTD == XML_TRUE</code> will make the parser behave as if 2499 1.1 tron the document had a DTD with an external subset. This holds true even if 2500 1.1 tron the external entity reference handler returns without action.</p> 2501 1.1 tron </div> 2502 1.1 tron 2503 1.1.1.6 christos <h4 id="XML_SetReturnNSTriplet">XML_SetReturnNSTriplet</h4> 2504 1.1.1.6 christos <pre class="fcndec"> 2505 1.1 tron void XMLCALL 2506 1.1 tron XML_SetReturnNSTriplet(XML_Parser parser, 2507 1.1 tron int do_nst); 2508 1.1 tron </pre> 2509 1.1 tron <div class="fcndef"> 2510 1.1 tron <p> 2511 1.1 tron This function only has an effect when using a parser created with 2512 1.1 tron <code><a href= "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>, 2513 1.1 tron i.e. when namespace processing is in effect. The <code>do_nst</code> 2514 1.1 tron sets whether or not prefixes are returned with names qualified with a 2515 1.1 tron namespace prefix. If this function is called with <code>do_nst</code> 2516 1.1 tron non-zero, then afterwards namespace qualified names (that is qualified 2517 1.1 tron with a prefix as opposed to belonging to a default namespace) are 2518 1.1 tron returned as a triplet with the three parts separated by the namespace 2519 1.1 tron separator specified when the parser was created. The order of 2520 1.1 tron returned parts is URI, local name, and prefix.</p> <p>If 2521 1.1 tron <code>do_nst</code> is zero, then namespaces are reported in the 2522 1.1 tron default manner, URI then local_name separated by the namespace 2523 1.1 tron separator.</p> 2524 1.1 tron </div> 2525 1.1 tron 2526 1.1.1.6 christos <h4 id="XML_DefaultCurrent">XML_DefaultCurrent</h4> 2527 1.1.1.6 christos <pre class="fcndec"> 2528 1.1 tron void XMLCALL 2529 1.1 tron XML_DefaultCurrent(XML_Parser parser); 2530 1.1 tron </pre> 2531 1.1 tron <div class="fcndef"> 2532 1.1 tron This can be called within a handler for a start element, end element, 2533 1.1 tron processing instruction or character data. It causes the corresponding 2534 1.1 tron markup to be passed to the default handler set by <code><a 2535 1.1 tron href="#XML_SetDefaultHandler" >XML_SetDefaultHandler</a></code> or 2536 1.1 tron <code><a href="#XML_SetDefaultHandlerExpand" 2537 1.1 tron >XML_SetDefaultHandlerExpand</a></code>. It does nothing if there is 2538 1.1 tron not a default handler. 2539 1.1 tron </div> 2540 1.1 tron 2541 1.1.1.6 christos <h4 id="XML_ExpatVersion">XML_ExpatVersion</h4> 2542 1.1.1.6 christos <pre class="fcndec"> 2543 1.1 tron XML_LChar * XMLCALL 2544 1.1 tron XML_ExpatVersion(); 2545 1.1 tron </pre> 2546 1.1 tron <div class="fcndef"> 2547 1.1 tron Return the library version as a string (e.g. <code>"expat_1.95.1"</code>). 2548 1.1 tron </div> 2549 1.1 tron 2550 1.1.1.6 christos <h4 id="XML_ExpatVersionInfo">XML_ExpatVersionInfo</h4> 2551 1.1.1.6 christos <pre class="fcndec"> 2552 1.1 tron struct XML_Expat_Version XMLCALL 2553 1.1 tron XML_ExpatVersionInfo(); 2554 1.1 tron </pre> 2555 1.1 tron <pre class="signature"> 2556 1.1 tron typedef struct { 2557 1.1 tron int major; 2558 1.1 tron int minor; 2559 1.1 tron int micro; 2560 1.1 tron } XML_Expat_Version; 2561 1.1 tron </pre> 2562 1.1 tron <div class="fcndef"> 2563 1.1 tron Return the library version information as a structure. 2564 1.1 tron Some macros are also defined that support compile-time tests of the 2565 1.1 tron library version: 2566 1.1 tron <ul> 2567 1.1 tron <li><code>XML_MAJOR_VERSION</code></li> 2568 1.1 tron <li><code>XML_MINOR_VERSION</code></li> 2569 1.1 tron <li><code>XML_MICRO_VERSION</code></li> 2570 1.1 tron </ul> 2571 1.1 tron Testing these constants is currently the best way to determine if 2572 1.1 tron particular parts of the Expat API are available. 2573 1.1 tron </div> 2574 1.1 tron 2575 1.1.1.6 christos <h4 id="XML_GetFeatureList">XML_GetFeatureList</h4> 2576 1.1.1.6 christos <pre class="fcndec"> 2577 1.1 tron const XML_Feature * XMLCALL 2578 1.1 tron XML_GetFeatureList(); 2579 1.1 tron </pre> 2580 1.1 tron <pre class="signature"> 2581 1.1 tron enum XML_FeatureEnum { 2582 1.1 tron XML_FEATURE_END = 0, 2583 1.1 tron XML_FEATURE_UNICODE, 2584 1.1 tron XML_FEATURE_UNICODE_WCHAR_T, 2585 1.1 tron XML_FEATURE_DTD, 2586 1.1 tron XML_FEATURE_CONTEXT_BYTES, 2587 1.1 tron XML_FEATURE_MIN_SIZE, 2588 1.1 tron XML_FEATURE_SIZEOF_XML_CHAR, 2589 1.1 tron XML_FEATURE_SIZEOF_XML_LCHAR, 2590 1.1 tron XML_FEATURE_NS, 2591 1.1 tron XML_FEATURE_LARGE_SIZE 2592 1.1 tron }; 2593 1.1 tron 2594 1.1 tron typedef struct { 2595 1.1 tron enum XML_FeatureEnum feature; 2596 1.1 tron XML_LChar *name; 2597 1.1 tron long int value; 2598 1.1 tron } XML_Feature; 2599 1.1 tron </pre> 2600 1.1 tron <div class="fcndef"> 2601 1.1 tron <p>Returns a list of "feature" records, providing details on how 2602 1.1 tron Expat was configured at compile time. Most applications should not 2603 1.1 tron need to worry about this, but this information is otherwise not 2604 1.1 tron available from Expat. This function allows code that does need to 2605 1.1 tron check these features to do so at runtime.</p> 2606 1.1 tron 2607 1.1 tron <p>The return value is an array of <code>XML_Feature</code>, 2608 1.1 tron terminated by a record with a <code>feature</code> of 2609 1.1.1.6.4.1 perseant <code>XML_FEATURE_END</code> and <code>name</code> of <code>NULL</code>, 2610 1.1 tron identifying the feature-test macros Expat was compiled with. Since an 2611 1.1 tron application that requires this kind of information needs to determine 2612 1.1 tron the type of character the <code>name</code> points to, records for the 2613 1.1 tron <code>XML_FEATURE_SIZEOF_XML_CHAR</code> and 2614 1.1 tron <code>XML_FEATURE_SIZEOF_XML_LCHAR</code> will be located at the 2615 1.1 tron beginning of the list, followed by <code>XML_FEATURE_UNICODE</code> 2616 1.1 tron and <code>XML_FEATURE_UNICODE_WCHAR_T</code>, if they are present at 2617 1.1 tron all.</p> 2618 1.1 tron 2619 1.1 tron <p>Some features have an associated value. If there isn't an 2620 1.1 tron associated value, the <code>value</code> field is set to 0. At this 2621 1.1 tron time, the following features have been defined to have values:</p> 2622 1.1 tron 2623 1.1 tron <dl> 2624 1.1 tron <dt><code>XML_FEATURE_SIZEOF_XML_CHAR</code></dt> 2625 1.1 tron <dd>The number of bytes occupied by one <code>XML_Char</code> 2626 1.1 tron character.</dd> 2627 1.1 tron <dt><code>XML_FEATURE_SIZEOF_XML_LCHAR</code></dt> 2628 1.1 tron <dd>The number of bytes occupied by one <code>XML_LChar</code> 2629 1.1 tron character.</dd> 2630 1.1 tron <dt><code>XML_FEATURE_CONTEXT_BYTES</code></dt> 2631 1.1 tron <dd>The maximum number of characters of context which can be 2632 1.1 tron reported by <code><a href= "#XML_GetInputContext" 2633 1.1 tron >XML_GetInputContext</a></code>.</dd> 2634 1.1 tron </dl> 2635 1.1 tron </div> 2636 1.1 tron 2637 1.1.1.6 christos <h4 id="XML_FreeContentModel">XML_FreeContentModel</h4> 2638 1.1.1.6 christos <pre class="fcndec"> 2639 1.1 tron void XMLCALL 2640 1.1 tron XML_FreeContentModel(XML_Parser parser, XML_Content *model); 2641 1.1 tron </pre> 2642 1.1 tron <div class="fcndef"> 2643 1.1 tron Function to deallocate the <code>model</code> argument passed to the 2644 1.1 tron <code>XML_ElementDeclHandler</code> callback set using <code><a 2645 1.1 tron href="#XML_SetElementDeclHandler" >XML_ElementDeclHandler</a></code>. 2646 1.1 tron This function should not be used for any other purpose. 2647 1.1 tron </div> 2648 1.1 tron 2649 1.1 tron <p>The following functions allow external code to share the memory 2650 1.1 tron allocator an <code>XML_Parser</code> has been configured to use. This 2651 1.1 tron is especially useful for third-party libraries that interact with a 2652 1.1 tron parser object created by application code, or heavily layered 2653 1.1 tron applications. This can be essential when using dynamically loaded 2654 1.1 tron libraries which use different C standard libraries (this can happen on 2655 1.1 tron Windows, at least).</p> 2656 1.1 tron 2657 1.1.1.6 christos <h4 id="XML_MemMalloc">XML_MemMalloc</h4> 2658 1.1.1.6 christos <pre class="fcndec"> 2659 1.1 tron void * XMLCALL 2660 1.1 tron XML_MemMalloc(XML_Parser parser, size_t size); 2661 1.1 tron </pre> 2662 1.1 tron <div class="fcndef"> 2663 1.1 tron Allocate <code>size</code> bytes of memory using the allocator the 2664 1.1 tron <code>parser</code> object has been configured to use. Returns a 2665 1.1.1.6.4.1 perseant pointer to the memory or <code>NULL</code> on failure. Memory allocated in this 2666 1.1 tron way must be freed using <code><a href="#XML_MemFree" 2667 1.1 tron >XML_MemFree</a></code>. 2668 1.1 tron </div> 2669 1.1 tron 2670 1.1.1.6 christos <h4 id="XML_MemRealloc">XML_MemRealloc</h4> 2671 1.1.1.6 christos <pre class="fcndec"> 2672 1.1 tron void * XMLCALL 2673 1.1 tron XML_MemRealloc(XML_Parser parser, void *ptr, size_t size); 2674 1.1 tron </pre> 2675 1.1 tron <div class="fcndef"> 2676 1.1 tron Allocate <code>size</code> bytes of memory using the allocator the 2677 1.1 tron <code>parser</code> object has been configured to use. 2678 1.1 tron <code>ptr</code> must point to a block of memory allocated by <code><a 2679 1.1 tron href="#XML_MemMalloc" >XML_MemMalloc</a></code> or 2680 1.1.1.6.4.1 perseant <code>XML_MemRealloc</code>, or be <code>NULL</code>. This function tries to 2681 1.1 tron expand the block pointed to by <code>ptr</code> if possible. Returns 2682 1.1.1.6.4.1 perseant a pointer to the memory or <code>NULL</code> on failure. On success, the original 2683 1.1 tron block has either been expanded or freed. On failure, the original 2684 1.1 tron block has not been freed; the caller is responsible for freeing the 2685 1.1 tron original block. Memory allocated in this way must be freed using 2686 1.1 tron <code><a href="#XML_MemFree" 2687 1.1 tron >XML_MemFree</a></code>. 2688 1.1 tron </div> 2689 1.1 tron 2690 1.1.1.6 christos <h4 id="XML_MemFree">XML_MemFree</h4> 2691 1.1.1.6 christos <pre class="fcndec"> 2692 1.1 tron void XMLCALL 2693 1.1 tron XML_MemFree(XML_Parser parser, void *ptr); 2694 1.1 tron </pre> 2695 1.1 tron <div class="fcndef"> 2696 1.1 tron Free a block of memory pointed to by <code>ptr</code>. The block must 2697 1.1 tron have been allocated by <code><a href="#XML_MemMalloc" 2698 1.1.1.6.4.1 perseant >XML_MemMalloc</a></code> or <code>XML_MemRealloc</code>, or be <code>NULL</code>. 2699 1.1 tron </div> 2700 1.1 tron 2701 1.1 tron <hr /> 2702 1.1.1.6 christos 2703 1.1.1.6 christos <div class="footer"> 2704 1.1.1.6 christos Found a bug in the documentation? 2705 1.1.1.6 christos <a href="https://github.com/libexpat/libexpat/issues">Please file a bug report.</a> 2706 1.1.1.6 christos </div> 2707 1.1.1.6 christos 2708 1.1 tron </div> 2709 1.1 tron </body> 2710 1.1 tron </html> 2711
Indexes created Mon Oct 26 00:26:21 UTC 2026