The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 1 | <?xml version="1.0" encoding="iso-8859-1"?> |
| 2 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" |
| 3 | "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> |
| 4 | <html> |
| 5 | <head> |
| 6 | <!-- Copyright 1999,2000 Clark Cooper <coopercc@netheaven.com> |
| 7 | All rights reserved. |
| 8 | This is free software. You may distribute or modify according to |
| 9 | the terms of the MIT/X License --> |
| 10 | <title>Expat XML Parser</title> |
| 11 | <meta name="author" content="Clark Cooper, coopercc@netheaven.com" /> |
| 12 | <meta http-equiv="Content-Style-Type" content="text/css" /> |
| 13 | <link href="style.css" rel="stylesheet" type="text/css" /> |
| 14 | </head> |
| 15 | <body> |
| 16 | <table cellspacing="0" cellpadding="0" width="100%"> |
| 17 | <tr> |
| 18 | <td class="corner"><img src="expat.png" alt="(Expat logo)" /></td> |
| 19 | <td class="banner"><h1>The Expat XML Parser</h1></td> |
| 20 | </tr> |
| 21 | <tr> |
Elliott Hughes | d07d5a7 | 2009-09-25 16:04:37 -0700 | [diff] [blame] | 22 | <td class="releaseno">Release 2.0.1</td> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 23 | <td></td> |
| 24 | </tr> |
| 25 | </table> |
| 26 | <div class="content"> |
| 27 | |
| 28 | <p>Expat is a library, written in C, for parsing XML documents. It's |
| 29 | the underlying XML parser for the open source Mozilla project, Perl's |
| 30 | <code>XML::Parser</code>, Python's <code>xml.parsers.expat</code>, and |
| 31 | other open-source XML parsers.</p> |
| 32 | |
| 33 | <p>This library is the creation of James Clark, who's also given us |
Elliott Hughes | 7247294 | 2018-01-10 08:36:10 -0800 | [diff] [blame] | 34 | groff (an nroff look-alike), Jade (an implementation of ISO's DSSSL |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 35 | stylesheet language for SGML), XP (a Java XML parser package), XT (a |
| 36 | Java XSL engine). James was also the technical lead on the XML |
| 37 | Working Group at W3C that produced the XML specification.</p> |
| 38 | |
| 39 | <p>This is free software, licensed under the <a |
| 40 | href="../COPYING">MIT/X Consortium license</a>. You may download it |
| 41 | from <a href="http://www.libexpat.org/">the Expat home page</a>. |
| 42 | </p> |
| 43 | |
| 44 | <p>The bulk of this document was originally commissioned as an article |
| 45 | by <a href="http://www.xml.com/">XML.com</a>. They graciously allowed |
| 46 | Clark Cooper to retain copyright and to distribute it with Expat. |
| 47 | This version has been substantially extended to include documentation |
| 48 | on features which have been added since the original article was |
| 49 | published, and additional information on using the original |
| 50 | interface.</p> |
| 51 | |
| 52 | <hr /> |
| 53 | <h2>Table of Contents</h2> |
| 54 | <ul> |
| 55 | <li><a href="#overview">Overview</a></li> |
| 56 | <li><a href="#building">Building and Installing</a></li> |
| 57 | <li><a href="#using">Using Expat</a></li> |
| 58 | <li><a href="#reference">Reference</a> |
| 59 | <ul> |
| 60 | <li><a href="#creation">Parser Creation Functions</a> |
| 61 | <ul> |
| 62 | <li><a href="#XML_ParserCreate">XML_ParserCreate</a></li> |
| 63 | <li><a href="#XML_ParserCreateNS">XML_ParserCreateNS</a></li> |
| 64 | <li><a href="#XML_ParserCreate_MM">XML_ParserCreate_MM</a></li> |
| 65 | <li><a href="#XML_ExternalEntityParserCreate">XML_ExternalEntityParserCreate</a></li> |
| 66 | <li><a href="#XML_ParserFree">XML_ParserFree</a></li> |
| 67 | <li><a href="#XML_ParserReset">XML_ParserReset</a></li> |
| 68 | </ul> |
| 69 | </li> |
| 70 | <li><a href="#parsing">Parsing Functions</a> |
| 71 | <ul> |
| 72 | <li><a href="#XML_Parse">XML_Parse</a></li> |
| 73 | <li><a href="#XML_ParseBuffer">XML_ParseBuffer</a></li> |
| 74 | <li><a href="#XML_GetBuffer">XML_GetBuffer</a></li> |
| 75 | <li><a href="#XML_StopParser">XML_StopParser</a></li> |
| 76 | <li><a href="#XML_ResumeParser">XML_ResumeParser</a></li> |
| 77 | <li><a href="#XML_GetParsingStatus">XML_GetParsingStatus</a></li> |
| 78 | </ul> |
| 79 | </li> |
| 80 | <li><a href="#setting">Handler Setting Functions</a> |
| 81 | <ul> |
| 82 | <li><a href="#XML_SetStartElementHandler">XML_SetStartElementHandler</a></li> |
| 83 | <li><a href="#XML_SetEndElementHandler">XML_SetEndElementHandler</a></li> |
| 84 | <li><a href="#XML_SetElementHandler">XML_SetElementHandler</a></li> |
| 85 | <li><a href="#XML_SetCharacterDataHandler">XML_SetCharacterDataHandler</a></li> |
| 86 | <li><a href="#XML_SetProcessingInstructionHandler">XML_SetProcessingInstructionHandler</a></li> |
| 87 | <li><a href="#XML_SetCommentHandler">XML_SetCommentHandler</a></li> |
| 88 | <li><a href="#XML_SetStartCdataSectionHandler">XML_SetStartCdataSectionHandler</a></li> |
| 89 | <li><a href="#XML_SetEndCdataSectionHandler">XML_SetEndCdataSectionHandler</a></li> |
| 90 | <li><a href="#XML_SetCdataSectionHandler">XML_SetCdataSectionHandler</a></li> |
| 91 | <li><a href="#XML_SetDefaultHandler">XML_SetDefaultHandler</a></li> |
| 92 | <li><a href="#XML_SetDefaultHandlerExpand">XML_SetDefaultHandlerExpand</a></li> |
| 93 | <li><a href="#XML_SetExternalEntityRefHandler">XML_SetExternalEntityRefHandler</a></li> |
| 94 | <li><a href="#XML_SetExternalEntityRefHandlerArg">XML_SetExternalEntityRefHandlerArg</a></li> |
| 95 | <li><a href="#XML_SetSkippedEntityHandler">XML_SetSkippedEntityHandler</a></li> |
| 96 | <li><a href="#XML_SetUnknownEncodingHandler">XML_SetUnknownEncodingHandler</a></li> |
| 97 | <li><a href="#XML_SetStartNamespaceDeclHandler">XML_SetStartNamespaceDeclHandler</a></li> |
| 98 | <li><a href="#XML_SetEndNamespaceDeclHandler">XML_SetEndNamespaceDeclHandler</a></li> |
| 99 | <li><a href="#XML_SetNamespaceDeclHandler">XML_SetNamespaceDeclHandler</a></li> |
| 100 | <li><a href="#XML_SetXmlDeclHandler">XML_SetXmlDeclHandler</a></li> |
| 101 | <li><a href="#XML_SetStartDoctypeDeclHandler">XML_SetStartDoctypeDeclHandler</a></li> |
| 102 | <li><a href="#XML_SetEndDoctypeDeclHandler">XML_SetEndDoctypeDeclHandler</a></li> |
| 103 | <li><a href="#XML_SetDoctypeDeclHandler">XML_SetDoctypeDeclHandler</a></li> |
| 104 | <li><a href="#XML_SetElementDeclHandler">XML_SetElementDeclHandler</a></li> |
| 105 | <li><a href="#XML_SetAttlistDeclHandler">XML_SetAttlistDeclHandler</a></li> |
| 106 | <li><a href="#XML_SetEntityDeclHandler">XML_SetEntityDeclHandler</a></li> |
| 107 | <li><a href="#XML_SetUnparsedEntityDeclHandler">XML_SetUnparsedEntityDeclHandler</a></li> |
| 108 | <li><a href="#XML_SetNotationDeclHandler">XML_SetNotationDeclHandler</a></li> |
| 109 | <li><a href="#XML_SetNotStandaloneHandler">XML_SetNotStandaloneHandler</a></li> |
| 110 | </ul> |
| 111 | </li> |
| 112 | <li><a href="#position">Parse Position and Error Reporting Functions</a> |
| 113 | <ul> |
| 114 | <li><a href="#XML_GetErrorCode">XML_GetErrorCode</a></li> |
| 115 | <li><a href="#XML_ErrorString">XML_ErrorString</a></li> |
| 116 | <li><a href="#XML_GetCurrentByteIndex">XML_GetCurrentByteIndex</a></li> |
| 117 | <li><a href="#XML_GetCurrentLineNumber">XML_GetCurrentLineNumber</a></li> |
| 118 | <li><a href="#XML_GetCurrentColumnNumber">XML_GetCurrentColumnNumber</a></li> |
| 119 | <li><a href="#XML_GetCurrentByteCount">XML_GetCurrentByteCount</a></li> |
| 120 | <li><a href="#XML_GetInputContext">XML_GetInputContext</a></li> |
| 121 | </ul> |
| 122 | </li> |
| 123 | <li><a href="#miscellaneous">Miscellaneous Functions</a> |
| 124 | <ul> |
| 125 | <li><a href="#XML_SetUserData">XML_SetUserData</a></li> |
| 126 | <li><a href="#XML_GetUserData">XML_GetUserData</a></li> |
| 127 | <li><a href="#XML_UseParserAsHandlerArg">XML_UseParserAsHandlerArg</a></li> |
| 128 | <li><a href="#XML_SetBase">XML_SetBase</a></li> |
| 129 | <li><a href="#XML_GetBase">XML_GetBase</a></li> |
| 130 | <li><a href="#XML_GetSpecifiedAttributeCount">XML_GetSpecifiedAttributeCount</a></li> |
| 131 | <li><a href="#XML_GetIdAttributeIndex">XML_GetIdAttributeIndex</a></li> |
Elliott Hughes | 35e432d | 2012-09-09 14:23:38 -0700 | [diff] [blame] | 132 | <li><a href="#XML_GetAttributeInfo">XML_GetAttributeInfo</a></li> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 133 | <li><a href="#XML_SetEncoding">XML_SetEncoding</a></li> |
| 134 | <li><a href="#XML_SetParamEntityParsing">XML_SetParamEntityParsing</a></li> |
Elliott Hughes | 35e432d | 2012-09-09 14:23:38 -0700 | [diff] [blame] | 135 | <li><a href="#XML_SetHashSalt">XML_SetHashSalt</a></li> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 136 | <li><a href="#XML_UseForeignDTD">XML_UseForeignDTD</a></li> |
| 137 | <li><a href="#XML_SetReturnNSTriplet">XML_SetReturnNSTriplet</a></li> |
| 138 | <li><a href="#XML_DefaultCurrent">XML_DefaultCurrent</a></li> |
| 139 | <li><a href="#XML_ExpatVersion">XML_ExpatVersion</a></li> |
| 140 | <li><a href="#XML_ExpatVersionInfo">XML_ExpatVersionInfo</a></li> |
| 141 | <li><a href="#XML_GetFeatureList">XML_GetFeatureList</a></li> |
| 142 | <li><a href="#XML_FreeContentModel">XML_FreeContentModel</a></li> |
| 143 | <li><a href="#XML_MemMalloc">XML_MemMalloc</a></li> |
| 144 | <li><a href="#XML_MemRealloc">XML_MemRealloc</a></li> |
| 145 | <li><a href="#XML_MemFree">XML_MemFree</a></li> |
| 146 | </ul> |
| 147 | </li> |
| 148 | </ul> |
| 149 | </li> |
| 150 | </ul> |
| 151 | |
| 152 | <hr /> |
| 153 | <h2><a name="overview">Overview</a></h2> |
| 154 | |
| 155 | <p>Expat is a stream-oriented parser. You register callback (or |
| 156 | handler) functions with the parser and then start feeding it the |
| 157 | document. As the parser recognizes parts of the document, it will |
| 158 | call the appropriate handler for that part (if you've registered one.) |
| 159 | The document is fed to the parser in pieces, so you can start parsing |
| 160 | before you have all the document. This also allows you to parse really |
| 161 | huge documents that won't fit into memory.</p> |
| 162 | |
| 163 | <p>Expat can be intimidating due to the many kinds of handlers and |
| 164 | options you can set. But you only need to learn four functions in |
| 165 | order to do 90% of what you'll want to do with it:</p> |
| 166 | |
| 167 | <dl> |
| 168 | |
| 169 | <dt><code><a href= "#XML_ParserCreate" |
| 170 | >XML_ParserCreate</a></code></dt> |
| 171 | <dd>Create a new parser object.</dd> |
| 172 | |
| 173 | <dt><code><a href= "#XML_SetElementHandler" |
| 174 | >XML_SetElementHandler</a></code></dt> |
| 175 | <dd>Set handlers for start and end tags.</dd> |
| 176 | |
| 177 | <dt><code><a href= "#XML_SetCharacterDataHandler" |
| 178 | >XML_SetCharacterDataHandler</a></code></dt> |
| 179 | <dd>Set handler for text.</dd> |
| 180 | |
| 181 | <dt><code><a href= "#XML_Parse" |
| 182 | >XML_Parse</a></code></dt> |
| 183 | <dd>Pass a buffer full of document to the parser</dd> |
| 184 | </dl> |
| 185 | |
| 186 | <p>These functions and others are described in the <a |
| 187 | href="#reference">reference</a> part of this document. The reference |
| 188 | section also describes in detail the parameters passed to the |
| 189 | different types of handlers.</p> |
| 190 | |
| 191 | <p>Let's look at a very simple example program that only uses 3 of the |
| 192 | above functions (it doesn't need to set a character handler.) The |
| 193 | program <a href="../examples/outline.c">outline.c</a> prints an |
| 194 | element outline, indenting child elements to distinguish them from the |
| 195 | parent element that contains them. The start handler does all the |
| 196 | work. It prints two indenting spaces for every level of ancestor |
| 197 | elements, then it prints the element and attribute |
| 198 | information. Finally it increments the global <code>Depth</code> |
| 199 | variable.</p> |
| 200 | |
| 201 | <pre class="eg"> |
| 202 | int Depth; |
| 203 | |
| 204 | void XMLCALL |
| 205 | start(void *data, const char *el, const char **attr) { |
| 206 | int i; |
| 207 | |
| 208 | for (i = 0; i < Depth; i++) |
| 209 | printf(" "); |
| 210 | |
| 211 | printf("%s", el); |
| 212 | |
| 213 | for (i = 0; attr[i]; i += 2) { |
| 214 | printf(" %s='%s'", attr[i], attr[i + 1]); |
| 215 | } |
| 216 | |
| 217 | printf("\n"); |
| 218 | Depth++; |
| 219 | } /* End of start handler */ |
| 220 | </pre> |
| 221 | |
| 222 | <p>The end tag simply does the bookkeeping work of decrementing |
| 223 | <code>Depth</code>.</p> |
| 224 | <pre class="eg"> |
| 225 | void XMLCALL |
| 226 | end(void *data, const char *el) { |
| 227 | Depth--; |
| 228 | } /* End of end handler */ |
| 229 | </pre> |
| 230 | |
| 231 | <p>Note the <code>XMLCALL</code> annotation used for the callbacks. |
| 232 | This is used to ensure that the Expat and the callbacks are using the |
| 233 | same calling convention in case the compiler options used for Expat |
| 234 | itself and the client code are different. Expat tries not to care |
| 235 | what the default calling convention is, though it may require that it |
| 236 | be compiled with a default convention of "cdecl" on some platforms. |
| 237 | For code which uses Expat, however, the calling convention is |
| 238 | specified by the <code>XMLCALL</code> annotation on most platforms; |
| 239 | callbacks should be defined using this annotation.</p> |
| 240 | |
| 241 | <p>The <code>XMLCALL</code> annotation was added in Expat 1.95.7, but |
| 242 | existing working Expat applications don't need to add it (since they |
| 243 | are already using the "cdecl" calling convention, or they wouldn't be |
| 244 | working). The annotation is only needed if the default calling |
| 245 | convention may be something other than "cdecl". To use the annotation |
| 246 | safely with older versions of Expat, you can conditionally define it |
| 247 | <em>after</em> including Expat's header file:</p> |
| 248 | |
| 249 | <pre class="eg"> |
| 250 | #include <expat.h> |
| 251 | |
| 252 | #ifndef XMLCALL |
| 253 | #if defined(_MSC_EXTENSIONS) && !defined(__BEOS__) && !defined(__CYGWIN__) |
| 254 | #define XMLCALL __cdecl |
| 255 | #elif defined(__GNUC__) |
| 256 | #define XMLCALL __attribute__((cdecl)) |
| 257 | #else |
| 258 | #define XMLCALL |
| 259 | #endif |
| 260 | #endif |
| 261 | </pre> |
| 262 | |
| 263 | <p>After creating the parser, the main program just has the job of |
| 264 | shoveling the document to the parser so that it can do its work.</p> |
| 265 | |
| 266 | <hr /> |
| 267 | <h2><a name="building">Building and Installing Expat</a></h2> |
| 268 | |
| 269 | <p>The Expat distribution comes as a compressed (with GNU gzip) tar |
| 270 | file. You may download the latest version from <a href= |
| 271 | "http://sourceforge.net/projects/expat/" >Source Forge</a>. After |
| 272 | unpacking this, cd into the directory. Then follow either the Win32 |
| 273 | directions or Unix directions below.</p> |
| 274 | |
| 275 | <h3>Building under Win32</h3> |
| 276 | |
| 277 | <p>If you're using the GNU compiler under cygwin, follow the Unix |
| 278 | directions in the next section. Otherwise if you have Microsoft's |
Haibo Huang | 40a7191 | 2019-10-11 11:13:39 -0700 | [diff] [blame] | 279 | Developer Studio installed, |
| 280 | you can use CMake to generate a <code>.sln</code> file, e.g. |
| 281 | <code> |
| 282 | cmake -G"Visual Studio 15 2017" -DCMAKE_BUILD_TYPE=RelWithDebInfo . |
| 283 | </code>, and build Expat using <code>msbuild /m expat.sln</code> after.</p> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 284 | |
| 285 | <p>Alternatively, you may download the Win32 binary package that |
| 286 | contains the "expat.h" include file and a pre-built DLL.</p> |
| 287 | |
| 288 | <h3>Building under Unix (or GNU)</h3> |
| 289 | |
| 290 | <p>First you'll need to run the configure shell script in order to |
| 291 | configure the Makefiles and headers for your system.</p> |
| 292 | |
| 293 | <p>If you're happy with all the defaults that configure picks for you, |
| 294 | and you have permission on your system to install into /usr/local, you |
| 295 | can install Expat with this sequence of commands:</p> |
| 296 | |
| 297 | <pre class="eg"> |
| 298 | ./configure |
| 299 | make |
| 300 | make install |
| 301 | </pre> |
| 302 | |
| 303 | <p>There are some options that you can provide to this script, but the |
| 304 | only one we'll mention here is the <code>--prefix</code> option. You |
| 305 | can find out all the options available by running configure with just |
| 306 | the <code>--help</code> option.</p> |
| 307 | |
| 308 | <p>By default, the configure script sets things up so that the library |
| 309 | gets installed in <code>/usr/local/lib</code> and the associated |
| 310 | header file in <code>/usr/local/include</code>. But if you were to |
| 311 | give the option, <code>--prefix=/home/me/mystuff</code>, then the |
| 312 | library and header would get installed in |
| 313 | <code>/home/me/mystuff/lib</code> and |
| 314 | <code>/home/me/mystuff/include</code> respectively.</p> |
| 315 | |
| 316 | <h3>Configuring Expat Using the Pre-Processor</h3> |
| 317 | |
| 318 | <p>Expat's feature set can be configured using a small number of |
| 319 | pre-processor definitions. The definition of this symbols does not |
| 320 | affect the set of entry points for Expat, only the behavior of the API |
| 321 | and the definition of character types in the case of |
| 322 | <code>XML_UNICODE_WCHAR_T</code>. The symbols are:</p> |
| 323 | |
| 324 | <dl class="cpp-symbols"> |
| 325 | <dt>XML_DTD</dt> |
| 326 | <dd>Include support for using and reporting DTD-based content. If |
| 327 | this is defined, default attribute values from an external DTD subset |
| 328 | are reported and attribute value normalization occurs based on the |
| 329 | type of attributes defined in the external subset. Without |
| 330 | this, Expat has a smaller memory footprint and can be faster, but will |
| 331 | not load external entities or process conditional sections. This does |
| 332 | not affect the set of functions available in the API.</dd> |
| 333 | |
| 334 | <dt>XML_NS</dt> |
| 335 | <dd>When defined, support for the <cite><a href= |
| 336 | "http://www.w3.org/TR/REC-xml-names/" >Namespaces in XML</a></cite> |
| 337 | specification is included.</dd> |
| 338 | |
| 339 | <dt>XML_UNICODE</dt> |
| 340 | <dd>When defined, character data reported to the application is |
| 341 | encoded in UTF-16 using wide characters of the type |
| 342 | <code>XML_Char</code>. This is implied if |
| 343 | <code>XML_UNICODE_WCHAR_T</code> is defined.</dd> |
| 344 | |
| 345 | <dt>XML_UNICODE_WCHAR_T</dt> |
| 346 | <dd>If defined, causes the <code>XML_Char</code> character type to be |
| 347 | defined using the <code>wchar_t</code> type; otherwise, <code>unsigned |
| 348 | short</code> is used. Defining this implies |
| 349 | <code>XML_UNICODE</code>.</dd> |
| 350 | |
| 351 | <dt>XML_LARGE_SIZE</dt> |
| 352 | <dd>If defined, causes the <code>XML_Size</code> and <code>XML_Index</code> |
| 353 | integer types to be at least 64 bits in size. This is intended to support |
| 354 | processing of very large input streams, where the return values of |
| 355 | <code><a href="#XML_GetCurrentByteIndex" >XML_GetCurrentByteIndex</a></code>, |
| 356 | <code><a href="#XML_GetCurrentLineNumber" >XML_GetCurrentLineNumber</a></code> and |
| 357 | <code><a href="#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code> |
| 358 | could overflow. It may not be supported by all compilers, and is turned |
| 359 | off by default.</dd> |
| 360 | |
| 361 | <dt>XML_CONTEXT_BYTES</dt> |
| 362 | <dd>The number of input bytes of markup context which the parser will |
| 363 | ensure are available for reporting via <code><a href= |
| 364 | "#XML_GetInputContext" >XML_GetInputContext</a></code>. This is |
Elliott Hughes | 7247294 | 2018-01-10 08:36:10 -0800 | [diff] [blame] | 365 | normally set to 1024, and must be set to a positive integer. If this |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 366 | is not defined, the input context will not be available and <code><a |
| 367 | href= "#XML_GetInputContext" >XML_GetInputContext</a></code> will |
| 368 | always report NULL. Without this, Expat has a smaller memory |
| 369 | footprint and can be faster.</dd> |
| 370 | |
| 371 | <dt>XML_STATIC</dt> |
| 372 | <dd>On Windows, this should be set if Expat is going to be linked |
| 373 | statically with the code that calls it; this is required to get all |
| 374 | the right MSVC magic annotations correct. This is ignored on other |
| 375 | platforms.</dd> |
Elliott Hughes | 35e432d | 2012-09-09 14:23:38 -0700 | [diff] [blame] | 376 | |
| 377 | <dt>XML_ATTR_INFO</dt> |
Elliott Hughes | 7247294 | 2018-01-10 08:36:10 -0800 | [diff] [blame] | 378 | <dd>If defined, makes the additional function <code><a href= |
Elliott Hughes | 35e432d | 2012-09-09 14:23:38 -0700 | [diff] [blame] | 379 | "#XML_GetAttributeInfo" >XML_GetAttributeInfo</a></code> available |
| 380 | for reporting attribute byte offsets.</dd> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 381 | </dl> |
| 382 | |
| 383 | <hr /> |
| 384 | <h2><a name="using">Using Expat</a></h2> |
| 385 | |
| 386 | <h3>Compiling and Linking Against Expat</h3> |
| 387 | |
| 388 | <p>Unless you installed Expat in a location not expected by your |
| 389 | compiler and linker, all you have to do to use Expat in your programs |
| 390 | is to include the Expat header (<code>#include <expat.h></code>) |
| 391 | in your files that make calls to it and to tell the linker that it |
| 392 | needs to link against the Expat library. On Unix systems, this would |
| 393 | usually be done with the <code>-lexpat</code> argument. Otherwise, |
| 394 | you'll need to tell the compiler where to look for the Expat header |
| 395 | and the linker where to find the Expat library. You may also need to |
Elliott Hughes | d07d5a7 | 2009-09-25 16:04:37 -0700 | [diff] [blame] | 396 | take steps to tell the operating system where to find this library at |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 397 | run time.</p> |
| 398 | |
| 399 | <p>On a Unix-based system, here's what a Makefile might look like when |
| 400 | Expat is installed in a standard location:</p> |
| 401 | |
| 402 | <pre class="eg"> |
| 403 | CC=cc |
| 404 | LDFLAGS= |
| 405 | LIBS= -lexpat |
| 406 | xmlapp: xmlapp.o |
| 407 | $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS) |
| 408 | </pre> |
| 409 | |
| 410 | <p>If you installed Expat in, say, <code>/home/me/mystuff</code>, then |
| 411 | the Makefile would look like this:</p> |
| 412 | |
| 413 | <pre class="eg"> |
| 414 | CC=cc |
| 415 | CFLAGS= -I/home/me/mystuff/include |
| 416 | LDFLAGS= |
| 417 | LIBS= -L/home/me/mystuff/lib -lexpat |
| 418 | xmlapp: xmlapp.o |
| 419 | $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS) |
| 420 | </pre> |
| 421 | |
| 422 | <p>You'd also have to set the environment variable |
| 423 | <code>LD_LIBRARY_PATH</code> to <code>/home/me/mystuff/lib</code> (or |
| 424 | to <code>${LD_LIBRARY_PATH}:/home/me/mystuff/lib</code> if |
| 425 | LD_LIBRARY_PATH already has some directories in it) in order to run |
| 426 | your application.</p> |
| 427 | |
| 428 | <h3>Expat Basics</h3> |
| 429 | |
| 430 | <p>As we saw in the example in the overview, the first step in parsing |
| 431 | an XML document with Expat is to create a parser object. There are <a |
| 432 | href="#creation">three functions</a> in the Expat API for creating a |
| 433 | parser object. However, only two of these (<code><a href= |
| 434 | "#XML_ParserCreate" >XML_ParserCreate</a></code> and <code><a href= |
| 435 | "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>) can be used for |
| 436 | constructing a parser for a top-level document. The object returned |
| 437 | by these functions is an opaque pointer (i.e. "expat.h" declares it as |
| 438 | void *) to data with further internal structure. In order to free the |
| 439 | memory associated with this object you must call <code><a href= |
| 440 | "#XML_ParserFree" >XML_ParserFree</a></code>. Note that if you have |
| 441 | provided any <a href="#userdata">user data</a> that gets stored in the |
| 442 | parser, then your application is responsible for freeing it prior to |
| 443 | calling <code>XML_ParserFree</code>.</p> |
| 444 | |
| 445 | <p>The objects returned by the parser creation functions are good for |
| 446 | parsing only one XML document or external parsed entity. If your |
| 447 | application needs to parse many XML documents, then it needs to create |
| 448 | a parser object for each one. The best way to deal with this is to |
| 449 | create a higher level object that contains all the default |
| 450 | initialization you want for your parser objects.</p> |
| 451 | |
| 452 | <p>Walking through a document hierarchy with a stream oriented parser |
| 453 | will require a good stack mechanism in order to keep track of current |
| 454 | context. For instance, to answer the simple question, "What element |
| 455 | does this text belong to?" requires a stack, since the parser may have |
| 456 | descended into other elements that are children of the current one and |
| 457 | has encountered this text on the way out.</p> |
| 458 | |
| 459 | <p>The things you're likely to want to keep on a stack are the |
| 460 | currently opened element and it's attributes. You push this |
| 461 | information onto the stack in the start handler and you pop it off in |
| 462 | the end handler.</p> |
| 463 | |
| 464 | <p>For some tasks, it is sufficient to just keep information on what |
| 465 | the depth of the stack is (or would be if you had one.) The outline |
| 466 | program shown above presents one example. Another such task would be |
| 467 | skipping over a complete element. When you see the start tag for the |
| 468 | element you want to skip, you set a skip flag and record the depth at |
| 469 | which the element started. When the end tag handler encounters the |
| 470 | same depth, the skipped element has ended and the flag may be |
| 471 | cleared. If you follow the convention that the root element starts at |
| 472 | 1, then you can use the same variable for skip flag and skip |
| 473 | depth.</p> |
| 474 | |
| 475 | <pre class="eg"> |
| 476 | void |
| 477 | init_info(Parseinfo *info) { |
| 478 | info->skip = 0; |
| 479 | info->depth = 1; |
| 480 | /* Other initializations here */ |
| 481 | } /* End of init_info */ |
| 482 | |
| 483 | void XMLCALL |
| 484 | rawstart(void *data, const char *el, const char **attr) { |
| 485 | Parseinfo *inf = (Parseinfo *) data; |
| 486 | |
| 487 | if (! inf->skip) { |
| 488 | if (should_skip(inf, el, attr)) { |
| 489 | inf->skip = inf->depth; |
| 490 | } |
| 491 | else |
| 492 | start(inf, el, attr); /* This does rest of start handling */ |
| 493 | } |
| 494 | |
| 495 | inf->depth++; |
| 496 | } /* End of rawstart */ |
| 497 | |
| 498 | void XMLCALL |
| 499 | rawend(void *data, const char *el) { |
| 500 | Parseinfo *inf = (Parseinfo *) data; |
| 501 | |
| 502 | inf->depth--; |
| 503 | |
| 504 | if (! inf->skip) |
| 505 | end(inf, el); /* This does rest of end handling */ |
| 506 | |
| 507 | if (inf->skip == inf->depth) |
| 508 | inf->skip = 0; |
| 509 | } /* End rawend */ |
| 510 | </pre> |
| 511 | |
| 512 | <p>Notice in the above example the difference in how depth is |
| 513 | manipulated in the start and end handlers. The end tag handler should |
| 514 | be the mirror image of the start tag handler. This is necessary to |
| 515 | properly model containment. Since, in the start tag handler, we |
| 516 | incremented depth <em>after</em> the main body of start tag code, then |
| 517 | in the end handler, we need to manipulate it <em>before</em> the main |
| 518 | body. If we'd decided to increment it first thing in the start |
| 519 | handler, then we'd have had to decrement it last thing in the end |
| 520 | handler.</p> |
| 521 | |
| 522 | <h3 id="userdata">Communicating between handlers</h3> |
| 523 | |
| 524 | <p>In order to be able to pass information between different handlers |
| 525 | without using globals, you'll need to define a data structure to hold |
| 526 | the shared variables. You can then tell Expat (with the <code><a href= |
| 527 | "#XML_SetUserData" >XML_SetUserData</a></code> function) to pass a |
| 528 | pointer to this structure to the handlers. This is the first |
| 529 | argument received by most handlers. In the <a href="#reference" |
| 530 | >reference section</a>, an argument to a callback function is named |
| 531 | <code>userData</code> and have type <code>void *</code> if the user |
| 532 | data is passed; it will have the type <code>XML_Parser</code> if the |
| 533 | parser itself is passed. When the parser is passed, the user data may |
| 534 | be retrieved using <code><a href="#XML_GetUserData" |
| 535 | >XML_GetUserData</a></code>.</p> |
| 536 | |
| 537 | <p>One common case where multiple calls to a single handler may need |
| 538 | to communicate using an application data structure is the case when |
| 539 | content passed to the character data handler (set by <code><a href= |
| 540 | "#XML_SetCharacterDataHandler" |
| 541 | >XML_SetCharacterDataHandler</a></code>) needs to be accumulated. A |
| 542 | common first-time mistake with any of the event-oriented interfaces to |
| 543 | an XML parser is to expect all the text contained in an element to be |
| 544 | reported by a single call to the character data handler. Expat, like |
| 545 | many other XML parsers, reports such data as a sequence of calls; |
| 546 | there's no way to know when the end of the sequence is reached until a |
| 547 | different callback is made. A buffer referenced by the user data |
| 548 | structure proves both an effective and convenient place to accumulate |
| 549 | character data.</p> |
| 550 | |
| 551 | <!-- XXX example needed here --> |
| 552 | |
| 553 | |
| 554 | <h3>XML Version</h3> |
| 555 | |
| 556 | <p>Expat is an XML 1.0 parser, and as such never complains based on |
| 557 | the value of the <code>version</code> pseudo-attribute in the XML |
| 558 | declaration, if present.</p> |
| 559 | |
| 560 | <p>If an application needs to check the version number (to support |
| 561 | alternate processing), it should use the <code><a href= |
| 562 | "#XML_SetXmlDeclHandler" >XML_SetXmlDeclHandler</a></code> function to |
| 563 | set a handler that uses the information in the XML declaration to |
| 564 | determine what to do. This example shows how to check that only a |
| 565 | version number of <code>"1.0"</code> is accepted:</p> |
| 566 | |
| 567 | <pre class="eg"> |
| 568 | static int wrong_version; |
| 569 | static XML_Parser parser; |
| 570 | |
| 571 | static void XMLCALL |
| 572 | xmldecl_handler(void *userData, |
| 573 | const XML_Char *version, |
| 574 | const XML_Char *encoding, |
| 575 | int standalone) |
| 576 | { |
| 577 | static const XML_Char Version_1_0[] = {'1', '.', '0', 0}; |
| 578 | |
| 579 | int i; |
| 580 | |
| 581 | for (i = 0; i < (sizeof(Version_1_0) / sizeof(Version_1_0[0])); ++i) { |
| 582 | if (version[i] != Version_1_0[i]) { |
| 583 | wrong_version = 1; |
| 584 | /* also clear all other handlers: */ |
| 585 | XML_SetCharacterDataHandler(parser, NULL); |
| 586 | ... |
| 587 | return; |
| 588 | } |
| 589 | } |
| 590 | ... |
| 591 | } |
| 592 | </pre> |
| 593 | |
| 594 | <h3>Namespace Processing</h3> |
| 595 | |
| 596 | <p>When the parser is created using the <code><a href= |
| 597 | "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>, function, Expat |
| 598 | performs namespace processing. Under namespace processing, Expat |
| 599 | consumes <code>xmlns</code> and <code>xmlns:...</code> attributes, |
| 600 | which declare namespaces for the scope of the element in which they |
| 601 | occur. This means that your start handler will not see these |
| 602 | attributes. Your application can still be informed of these |
| 603 | declarations by setting namespace declaration handlers with <a href= |
| 604 | "#XML_SetNamespaceDeclHandler" |
| 605 | ><code>XML_SetNamespaceDeclHandler</code></a>.</p> |
| 606 | |
| 607 | <p>Element type and attribute names that belong to a given namespace |
| 608 | are passed to the appropriate handler in expanded form. By default |
| 609 | this expanded form is a concatenation of the namespace URI, the |
| 610 | separator character (which is the 2nd argument to <code><a href= |
| 611 | "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>), and the local |
| 612 | name (i.e. the part after the colon). Names with undeclared prefixes |
| 613 | are not well-formed when namespace processing is enabled, and will |
| 614 | trigger an error. Unprefixed attribute names are never expanded, |
| 615 | and unprefixed element names are only expanded when they are in the |
| 616 | scope of a default namespace.</p> |
| 617 | |
| 618 | <p>However if <code><a href= "#XML_SetReturnNSTriplet" |
| 619 | >XML_SetReturnNSTriplet</a></code> has been called with a non-zero |
| 620 | <code>do_nst</code> parameter, then the expanded form for names with |
| 621 | an explicit prefix is a concatenation of: URI, separator, local name, |
| 622 | separator, prefix.</p> |
| 623 | |
| 624 | <p>You can set handlers for the start of a namespace declaration and |
| 625 | for the end of a scope of a declaration with the <code><a href= |
| 626 | "#XML_SetNamespaceDeclHandler" >XML_SetNamespaceDeclHandler</a></code> |
| 627 | function. The StartNamespaceDeclHandler is called prior to the start |
| 628 | tag handler and the EndNamespaceDeclHandler is called after the |
| 629 | corresponding end tag that ends the namespace's scope. The namespace |
| 630 | start handler gets passed the prefix and URI for the namespace. For a |
| 631 | default namespace declaration (xmlns='...'), the prefix will be null. |
| 632 | The URI will be null for the case where the default namespace is being |
| 633 | unset. The namespace end handler just gets the prefix for the closing |
| 634 | scope.</p> |
| 635 | |
| 636 | <p>These handlers are called for each declaration. So if, for |
| 637 | instance, a start tag had three namespace declarations, then the |
| 638 | StartNamespaceDeclHandler would be called three times before the start |
| 639 | tag handler is called, once for each declaration.</p> |
| 640 | |
| 641 | <h3>Character Encodings</h3> |
| 642 | |
| 643 | <p>While XML is based on Unicode, and every XML processor is required |
| 644 | to recognized UTF-8 and UTF-16 (1 and 2 byte encodings of Unicode), |
| 645 | other encodings may be declared in XML documents or entities. For the |
| 646 | main document, an XML declaration may contain an encoding |
| 647 | declaration:</p> |
| 648 | <pre> |
| 649 | <?xml version="1.0" encoding="ISO-8859-2"?> |
| 650 | </pre> |
| 651 | |
| 652 | <p>External parsed entities may begin with a text declaration, which |
| 653 | looks like an XML declaration with just an encoding declaration:</p> |
| 654 | <pre> |
| 655 | <?xml encoding="Big5"?> |
| 656 | </pre> |
| 657 | |
| 658 | <p>With Expat, you may also specify an encoding at the time of |
| 659 | creating a parser. This is useful when the encoding information may |
| 660 | come from a source outside the document itself (like a higher level |
| 661 | protocol.)</p> |
| 662 | |
| 663 | <p><a name="builtin_encodings"></a>There are four built-in encodings |
| 664 | in Expat:</p> |
| 665 | <ul> |
| 666 | <li>UTF-8</li> |
| 667 | <li>UTF-16</li> |
| 668 | <li>ISO-8859-1</li> |
| 669 | <li>US-ASCII</li> |
| 670 | </ul> |
| 671 | |
| 672 | <p>Anything else discovered in an encoding declaration or in the |
| 673 | protocol encoding specified in the parser constructor, triggers a call |
| 674 | to the <code>UnknownEncodingHandler</code>. This handler gets passed |
| 675 | the encoding name and a pointer to an <code>XML_Encoding</code> data |
| 676 | structure. Your handler must fill in this structure and return |
| 677 | <code>XML_STATUS_OK</code> if it knows how to deal with the |
| 678 | encoding. Otherwise the handler should return |
| 679 | <code>XML_STATUS_ERROR</code>. The handler also gets passed a pointer |
| 680 | to an optional application data structure that you may indicate when |
| 681 | you set the handler.</p> |
| 682 | |
| 683 | <p>Expat places restrictions on character encodings that it can |
| 684 | support by filling in the <code>XML_Encoding</code> structure. |
| 685 | include file:</p> |
| 686 | <ol> |
| 687 | <li>Every ASCII character that can appear in a well-formed XML document |
| 688 | must be represented by a single byte, and that byte must correspond to |
| 689 | it's ASCII encoding (except for the characters $@\^'{}~)</li> |
| 690 | <li>Characters must be encoded in 4 bytes or less.</li> |
| 691 | <li>All characters encoded must have Unicode scalar values less than or |
| 692 | equal to 65535 (0xFFFF)<em>This does not apply to the built-in support |
| 693 | for UTF-16 and UTF-8</em></li> |
| 694 | <li>No character may be encoded by more that one distinct sequence of |
| 695 | bytes</li> |
| 696 | </ol> |
| 697 | |
| 698 | <p><code>XML_Encoding</code> contains an array of integers that |
| 699 | correspond to the 1st byte of an encoding sequence. If the value in |
| 700 | the array for a byte is zero or positive, then the byte is a single |
| 701 | byte encoding that encodes the Unicode scalar value contained in the |
| 702 | array. A -1 in this array indicates a malformed byte. If the value is |
| 703 | -2, -3, or -4, then the byte is the beginning of a 2, 3, or 4 byte |
| 704 | sequence respectively. Multi-byte sequences are sent to the convert |
| 705 | function pointed at in the <code>XML_Encoding</code> structure. This |
| 706 | function should return the Unicode scalar value for the sequence or -1 |
| 707 | if the sequence is malformed.</p> |
| 708 | |
| 709 | <p>One pitfall that novice Expat users are likely to fall into is that |
| 710 | although Expat may accept input in various encodings, the strings that |
| 711 | it passes to the handlers are always encoded in UTF-8 or UTF-16 |
| 712 | (depending on how Expat was compiled). Your application is responsible |
| 713 | for any translation of these strings into other encodings.</p> |
| 714 | |
| 715 | <h3>Handling External Entity References</h3> |
| 716 | |
| 717 | <p>Expat does not read or parse external entities directly. Note that |
| 718 | any external DTD is a special case of an external entity. If you've |
| 719 | set no <code>ExternalEntityRefHandler</code>, then external entity |
| 720 | references are silently ignored. Otherwise, it calls your handler with |
| 721 | the information needed to read and parse the external entity.</p> |
| 722 | |
| 723 | <p>Your handler isn't actually responsible for parsing the entity, but |
| 724 | it is responsible for creating a subsidiary parser with <code><a href= |
| 725 | "#XML_ExternalEntityParserCreate" |
| 726 | >XML_ExternalEntityParserCreate</a></code> that will do the job. This |
| 727 | returns an instance of <code>XML_Parser</code> that has handlers and |
| 728 | other data structures initialized from the parent parser. You may then |
| 729 | use <code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a |
| 730 | href= "#XML_ParseBuffer">XML_ParseBuffer</a></code> calls against this |
| 731 | parser. Since external entities my refer to other external entities, |
| 732 | your handler should be prepared to be called recursively.</p> |
| 733 | |
| 734 | <h3>Parsing DTDs</h3> |
| 735 | |
| 736 | <p>In order to parse parameter entities, before starting the parse, |
| 737 | you must call <code><a href= "#XML_SetParamEntityParsing" |
| 738 | >XML_SetParamEntityParsing</a></code> with one of the following |
| 739 | arguments:</p> |
| 740 | <dl> |
| 741 | <dt><code>XML_PARAM_ENTITY_PARSING_NEVER</code></dt> |
| 742 | <dd>Don't parse parameter entities or the external subset</dd> |
| 743 | <dt><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></dt> |
Elliott Hughes | 7247294 | 2018-01-10 08:36:10 -0800 | [diff] [blame] | 744 | <dd>Parse parameter entities and the external subset unless |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 745 | <code>standalone</code> was set to "yes" in the XML declaration.</dd> |
| 746 | <dt><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></dt> |
| 747 | <dd>Always parse parameter entities and the external subset</dd> |
| 748 | </dl> |
| 749 | |
| 750 | <p>In order to read an external DTD, you also have to set an external |
| 751 | entity reference handler as described above.</p> |
| 752 | |
| 753 | <h3 id="stop-resume">Temporarily Stopping Parsing</h3> |
| 754 | |
| 755 | <p>Expat 1.95.8 introduces a new feature: its now possible to stop |
| 756 | parsing temporarily from within a handler function, even if more data |
| 757 | has already been passed into the parser. Applications for this |
| 758 | include</p> |
| 759 | |
| 760 | <ul> |
| 761 | <li>Supporting the <a href= "http://www.w3.org/TR/xinclude/" |
| 762 | >XInclude</a> specification.</li> |
| 763 | |
| 764 | <li>Delaying further processing until additional information is |
| 765 | available from some other source.</li> |
| 766 | |
| 767 | <li>Adjusting processor load as task priorities shift within an |
| 768 | application.</li> |
| 769 | |
| 770 | <li>Stopping parsing completely (simply free or reset the parser |
| 771 | instead of resuming in the outer parsing loop). This can be useful |
Elliott Hughes | 7247294 | 2018-01-10 08:36:10 -0800 | [diff] [blame] | 772 | if an application-domain error is found in the XML being parsed or if |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 773 | the result of the parse is determined not to be useful after |
| 774 | all.</li> |
| 775 | </ul> |
| 776 | |
| 777 | <p>To take advantage of this feature, the main parsing loop of an |
| 778 | application needs to support this specifically. It cannot be |
| 779 | supported with a parsing loop compatible with Expat 1.95.7 or |
| 780 | earlier (though existing loops will continue to work without |
| 781 | supporting the stop/resume feature).</p> |
| 782 | |
| 783 | <p>An application that uses this feature for a single parser will have |
| 784 | the rough structure (in pseudo-code):</p> |
| 785 | |
| 786 | <pre class="pseudocode"> |
| 787 | fd = open_input() |
| 788 | p = create_parser() |
| 789 | |
| 790 | if parse_xml(p, fd) { |
| 791 | /* suspended */ |
| 792 | |
| 793 | int suspended = 1; |
| 794 | |
| 795 | while (suspended) { |
| 796 | do_something_else() |
| 797 | if ready_to_resume() { |
| 798 | suspended = continue_parsing(p, fd); |
| 799 | } |
| 800 | } |
| 801 | } |
| 802 | </pre> |
| 803 | |
| 804 | <p>An application that may resume any of several parsers based on |
| 805 | input (either from the XML being parsed or some other source) will |
| 806 | certainly have more interesting control structures.</p> |
| 807 | |
| 808 | <p>This C function could be used for the <code>parse_xml</code> |
| 809 | function mentioned in the pseudo-code above:</p> |
| 810 | |
| 811 | <pre class="eg"> |
| 812 | #define BUFF_SIZE 10240 |
| 813 | |
| 814 | /* Parse a document from the open file descriptor 'fd' until the parse |
| 815 | is complete (the document has been completely parsed, or there's |
| 816 | been an error), or the parse is stopped. Return non-zero when |
| 817 | the parse is merely suspended. |
| 818 | */ |
| 819 | int |
| 820 | parse_xml(XML_Parser p, int fd) |
| 821 | { |
| 822 | for (;;) { |
| 823 | int last_chunk; |
| 824 | int bytes_read; |
| 825 | enum XML_Status status; |
| 826 | |
| 827 | void *buff = XML_GetBuffer(p, BUFF_SIZE); |
| 828 | if (buff == NULL) { |
| 829 | /* handle error... */ |
| 830 | return 0; |
| 831 | } |
| 832 | bytes_read = read(fd, buff, BUFF_SIZE); |
| 833 | if (bytes_read < 0) { |
| 834 | /* handle error... */ |
| 835 | return 0; |
| 836 | } |
| 837 | status = XML_ParseBuffer(p, bytes_read, bytes_read == 0); |
| 838 | switch (status) { |
| 839 | case XML_STATUS_ERROR: |
| 840 | /* handle error... */ |
| 841 | return 0; |
| 842 | case XML_STATUS_SUSPENDED: |
| 843 | return 1; |
| 844 | } |
| 845 | if (bytes_read == 0) |
| 846 | return 0; |
| 847 | } |
| 848 | } |
| 849 | </pre> |
| 850 | |
| 851 | <p>The corresponding <code>continue_parsing</code> function is |
| 852 | somewhat simpler, since it only need deal with the return code from |
| 853 | <code><a href= "#XML_ResumeParser">XML_ResumeParser</a></code>; it can |
| 854 | delegate the input handling to the <code>parse_xml</code> |
| 855 | function:</p> |
| 856 | |
| 857 | <pre class="eg"> |
| 858 | /* Continue parsing a document which had been suspended. The 'p' and |
| 859 | 'fd' arguments are the same as passed to parse_xml(). Return |
| 860 | non-zero when the parse is suspended. |
| 861 | */ |
| 862 | int |
| 863 | continue_parsing(XML_Parser p, int fd) |
| 864 | { |
| 865 | enum XML_Status status = XML_ResumeParser(p); |
| 866 | switch (status) { |
| 867 | case XML_STATUS_ERROR: |
| 868 | /* handle error... */ |
| 869 | return 0; |
| 870 | case XML_ERROR_NOT_SUSPENDED: |
| 871 | /* handle error... */ |
| 872 | return 0;. |
| 873 | case XML_STATUS_SUSPENDED: |
| 874 | return 1; |
| 875 | } |
| 876 | return parse_xml(p, fd); |
| 877 | } |
| 878 | </pre> |
| 879 | |
| 880 | <p>Now that we've seen what a mess the top-level parsing loop can |
| 881 | become, what have we gained? Very simply, we can now use the <code><a |
| 882 | href= "#XML_StopParser" >XML_StopParser</a></code> function to stop |
| 883 | parsing, without having to go to great lengths to avoid additional |
| 884 | processing that we're expecting to ignore. As a bonus, we get to stop |
| 885 | parsing <em>temporarily</em>, and come back to it when we're |
| 886 | ready.</p> |
| 887 | |
| 888 | <p>To stop parsing from a handler function, use the <code><a href= |
| 889 | "#XML_StopParser" >XML_StopParser</a></code> function. This function |
| 890 | takes two arguments; the parser being stopped and a flag indicating |
| 891 | whether the parse can be resumed in the future.</p> |
| 892 | |
| 893 | <!-- XXX really need more here --> |
| 894 | |
| 895 | |
| 896 | <hr /> |
| 897 | <!-- ================================================================ --> |
| 898 | |
| 899 | <h2><a name="reference">Expat Reference</a></h2> |
| 900 | |
| 901 | <h3><a name="creation">Parser Creation</a></h3> |
| 902 | |
| 903 | <pre class="fcndec" id="XML_ParserCreate"> |
| 904 | XML_Parser XMLCALL |
| 905 | XML_ParserCreate(const XML_Char *encoding); |
| 906 | </pre> |
| 907 | <div class="fcndef"> |
| 908 | Construct a new parser. If encoding is non-null, it specifies a |
| 909 | character encoding to use for the document. This overrides the document |
| 910 | encoding declaration. There are four built-in encodings: |
| 911 | <ul> |
| 912 | <li>US-ASCII</li> |
| 913 | <li>UTF-8</li> |
| 914 | <li>UTF-16</li> |
| 915 | <li>ISO-8859-1</li> |
| 916 | </ul> |
| 917 | Any other value will invoke a call to the UnknownEncodingHandler. |
| 918 | </div> |
| 919 | |
| 920 | <pre class="fcndec" id="XML_ParserCreateNS"> |
| 921 | XML_Parser XMLCALL |
| 922 | XML_ParserCreateNS(const XML_Char *encoding, |
| 923 | XML_Char sep); |
| 924 | </pre> |
| 925 | <div class="fcndef"> |
| 926 | Constructs a new parser that has namespace processing in effect. Namespace |
| 927 | expanded element names and attribute names are returned as a concatenation |
| 928 | of the namespace URI, <em>sep</em>, and the local part of the name. This |
Elliott Hughes | 35e432d | 2012-09-09 14:23:38 -0700 | [diff] [blame] | 929 | means that you should pick a character for <em>sep</em> that can't be part |
| 930 | of an URI. Since Expat does not check namespace URIs for conformance, the |
| 931 | only safe choice for a namespace separator is a character that is illegal |
| 932 | in XML. For instance, <code>'\xFF'</code> is not legal in UTF-8, and |
| 933 | <code>'\xFFFF'</code> is not legal in UTF-16. There is a special case when |
| 934 | <em>sep</em> is the null character <code>'\0'</code>: the namespace URI and |
| 935 | the local part will be concatenated without any separator - this is intended |
| 936 | to support RDF processors. It is a programming error to use the null separator |
| 937 | with <a href= "#XML_SetReturnNSTriplet">namespace triplets</a>.</div> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 938 | |
| 939 | <pre class="fcndec" id="XML_ParserCreate_MM"> |
| 940 | XML_Parser XMLCALL |
| 941 | XML_ParserCreate_MM(const XML_Char *encoding, |
| 942 | const XML_Memory_Handling_Suite *ms, |
| 943 | const XML_Char *sep); |
| 944 | </pre> |
| 945 | <pre class="signature"> |
| 946 | typedef struct { |
| 947 | void *(XMLCALL *malloc_fcn)(size_t size); |
| 948 | void *(XMLCALL *realloc_fcn)(void *ptr, size_t size); |
| 949 | void (XMLCALL *free_fcn)(void *ptr); |
| 950 | } XML_Memory_Handling_Suite; |
| 951 | </pre> |
| 952 | <div class="fcndef"> |
| 953 | <p>Construct a new parser using the suite of memory handling functions |
| 954 | specified in <code>ms</code>. If <code>ms</code> is NULL, then use the |
| 955 | standard set of memory management functions. If <code>sep</code> is |
| 956 | non NULL, then namespace processing is enabled in the created parser |
| 957 | and the character pointed at by sep is used as the separator between |
| 958 | the namespace URI and the local part of the name.</p> |
| 959 | </div> |
| 960 | |
| 961 | <pre class="fcndec" id="XML_ExternalEntityParserCreate"> |
| 962 | XML_Parser XMLCALL |
| 963 | XML_ExternalEntityParserCreate(XML_Parser p, |
| 964 | const XML_Char *context, |
| 965 | const XML_Char *encoding); |
| 966 | </pre> |
| 967 | <div class="fcndef"> |
| 968 | Construct a new <code>XML_Parser</code> object for parsing an external |
| 969 | general entity. Context is the context argument passed in a call to a |
| 970 | ExternalEntityRefHandler. Other state information such as handlers, |
| 971 | user data, namespace processing is inherited from the parser passed as |
| 972 | the 1st argument. So you shouldn't need to call any of the behavior |
| 973 | changing functions on this parser (unless you want it to act |
| 974 | differently than the parent parser). |
| 975 | </div> |
| 976 | |
| 977 | <pre class="fcndec" id="XML_ParserFree"> |
| 978 | void XMLCALL |
| 979 | XML_ParserFree(XML_Parser p); |
| 980 | </pre> |
| 981 | <div class="fcndef"> |
| 982 | Free memory used by the parser. Your application is responsible for |
| 983 | freeing any memory associated with <a href="#userdata">user data</a>. |
| 984 | </div> |
| 985 | |
| 986 | <pre class="fcndec" id="XML_ParserReset"> |
| 987 | XML_Bool XMLCALL |
| 988 | XML_ParserReset(XML_Parser p, |
| 989 | const XML_Char *encoding); |
| 990 | </pre> |
| 991 | <div class="fcndef"> |
| 992 | Clean up the memory structures maintained by the parser so that it may |
| 993 | be used again. After this has been called, <code>parser</code> is |
| 994 | ready to start parsing a new document. All handlers are cleared from |
| 995 | the parser, except for the unknownEncodingHandler. The parser's external |
| 996 | state is re-initialized except for the values of ns and ns_triplets. |
| 997 | This function may not be used on a parser created using <code><a href= |
| 998 | "#XML_ExternalEntityParserCreate" >XML_ExternalEntityParserCreate</a |
| 999 | ></code>; it will return <code>XML_FALSE</code> in that case. Returns |
| 1000 | <code>XML_TRUE</code> on success. Your application is responsible for |
| 1001 | dealing with any memory associated with <a href="#userdata">user data</a>. |
| 1002 | </div> |
| 1003 | |
| 1004 | <h3><a name="parsing">Parsing</a></h3> |
| 1005 | |
| 1006 | <p>To state the obvious: the three parsing functions <code><a href= |
| 1007 | "#XML_Parse" >XML_Parse</a></code>, <code><a href= "#XML_ParseBuffer"> |
| 1008 | XML_ParseBuffer</a></code> and <code><a href= "#XML_GetBuffer"> |
| 1009 | XML_GetBuffer</a></code> must not be called from within a handler |
| 1010 | unless they operate on a separate parser instance, that is, one that |
| 1011 | did not call the handler. For example, it is OK to call the parsing |
| 1012 | functions from within an <code>XML_ExternalEntityRefHandler</code>, |
| 1013 | if they apply to the parser created by |
| 1014 | <code><a href= "#XML_ExternalEntityParserCreate" |
| 1015 | >XML_ExternalEntityParserCreate</a></code>.</p> |
| 1016 | |
| 1017 | <p>Note: the <code>len</code> argument passed to these functions |
| 1018 | should be considerably less than the maximum value for an integer, |
| 1019 | as it could create an integer overflow situation if the added |
| 1020 | lengths of a buffer and the unprocessed portion of the previous buffer |
| 1021 | exceed the maximum integer value. Input data at the end of a buffer |
| 1022 | will remain unprocessed if it is part of an XML token for which the |
| 1023 | end is not part of that buffer.</p> |
| 1024 | |
| 1025 | <pre class="fcndec" id="XML_Parse"> |
| 1026 | enum XML_Status XMLCALL |
| 1027 | XML_Parse(XML_Parser p, |
| 1028 | const char *s, |
| 1029 | int len, |
| 1030 | int isFinal); |
| 1031 | </pre> |
| 1032 | <pre class="signature"> |
| 1033 | enum XML_Status { |
| 1034 | XML_STATUS_ERROR = 0, |
| 1035 | XML_STATUS_OK = 1 |
| 1036 | }; |
| 1037 | </pre> |
| 1038 | <div class="fcndef"> |
| 1039 | Parse some more of the document. The string <code>s</code> is a buffer |
| 1040 | containing part (or perhaps all) of the document. The number of bytes of s |
| 1041 | that are part of the document is indicated by <code>len</code>. This means |
| 1042 | that <code>s</code> doesn't have to be null terminated. It also means that |
| 1043 | if <code>len</code> is larger than the number of bytes in the block of |
| 1044 | memory that <code>s</code> points at, then a memory fault is likely. The |
| 1045 | <code>isFinal</code> parameter informs the parser that this is the last |
| 1046 | piece of the document. Frequently, the last piece is empty (i.e. |
| 1047 | <code>len</code> is zero.) |
| 1048 | If a parse error occurred, it returns <code>XML_STATUS_ERROR</code>. |
| 1049 | Otherwise it returns <code>XML_STATUS_OK</code> value. |
| 1050 | </div> |
| 1051 | |
| 1052 | <pre class="fcndec" id="XML_ParseBuffer"> |
| 1053 | enum XML_Status XMLCALL |
| 1054 | XML_ParseBuffer(XML_Parser p, |
| 1055 | int len, |
| 1056 | int isFinal); |
| 1057 | </pre> |
| 1058 | <div class="fcndef"> |
| 1059 | This is just like <code><a href= "#XML_Parse" >XML_Parse</a></code>, |
| 1060 | except in this case Expat provides the buffer. By obtaining the |
| 1061 | buffer from Expat with the <code><a href= "#XML_GetBuffer" |
| 1062 | >XML_GetBuffer</a></code> function, the application can avoid double |
| 1063 | copying of the input. |
| 1064 | </div> |
| 1065 | |
| 1066 | <pre class="fcndec" id="XML_GetBuffer"> |
| 1067 | void * XMLCALL |
| 1068 | XML_GetBuffer(XML_Parser p, |
| 1069 | int len); |
| 1070 | </pre> |
| 1071 | <div class="fcndef"> |
| 1072 | Obtain a buffer of size <code>len</code> to read a piece of the document |
| 1073 | into. A NULL value is returned if Expat can't allocate enough memory for |
| 1074 | this buffer. This has to be called prior to every call to |
| 1075 | <code><a href= "#XML_ParseBuffer" >XML_ParseBuffer</a></code>. A |
| 1076 | typical use would look like this: |
| 1077 | |
| 1078 | <pre class="eg"> |
| 1079 | for (;;) { |
| 1080 | int bytes_read; |
| 1081 | void *buff = XML_GetBuffer(p, BUFF_SIZE); |
| 1082 | if (buff == NULL) { |
| 1083 | /* handle error */ |
| 1084 | } |
| 1085 | |
| 1086 | bytes_read = read(docfd, buff, BUFF_SIZE); |
| 1087 | if (bytes_read < 0) { |
| 1088 | /* handle error */ |
| 1089 | } |
| 1090 | |
| 1091 | if (! XML_ParseBuffer(p, bytes_read, bytes_read == 0)) { |
| 1092 | /* handle parse error */ |
| 1093 | } |
| 1094 | |
| 1095 | if (bytes_read == 0) |
| 1096 | break; |
| 1097 | } |
| 1098 | </pre> |
| 1099 | </div> |
| 1100 | |
| 1101 | <pre class="fcndec" id="XML_StopParser"> |
| 1102 | enum XML_Status XMLCALL |
| 1103 | XML_StopParser(XML_Parser p, |
| 1104 | XML_Bool resumable); |
| 1105 | </pre> |
| 1106 | <div class="fcndef"> |
| 1107 | |
| 1108 | <p>Stops parsing, causing <code><a href= "#XML_Parse" |
| 1109 | >XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer" |
| 1110 | >XML_ParseBuffer</a></code> to return. Must be called from within a |
| 1111 | call-back handler, except when aborting (when <code>resumable</code> |
| 1112 | is <code>XML_FALSE</code>) an already suspended parser. Some |
| 1113 | call-backs may still follow because they would otherwise get |
| 1114 | lost, including |
| 1115 | <ul> |
| 1116 | <li> the end element handler for empty elements when stopped in the |
| 1117 | start element handler,</li> |
Elliott Hughes | d07d5a7 | 2009-09-25 16:04:37 -0700 | [diff] [blame] | 1118 | <li> the end namespace declaration handler when stopped in the end |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 1119 | element handler,</li> |
Elliott Hughes | d07d5a7 | 2009-09-25 16:04:37 -0700 | [diff] [blame] | 1120 | <li> the character data handler when stopped in the character data handler |
| 1121 | while making multiple call-backs on a contiguous chunk of characters,</li> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 1122 | </ul> |
| 1123 | and possibly others.</p> |
| 1124 | |
| 1125 | <p>This can be called from most handlers, including DTD related |
| 1126 | call-backs, except when parsing an external parameter entity and |
| 1127 | <code>resumable</code> is <code>XML_TRUE</code>. Returns |
| 1128 | <code>XML_STATUS_OK</code> when successful, |
| 1129 | <code>XML_STATUS_ERROR</code> otherwise. The possible error codes |
| 1130 | are:</p> |
| 1131 | <dl> |
| 1132 | <dt><code>XML_ERROR_SUSPENDED</code></dt> |
| 1133 | <dd>when suspending an already suspended parser.</dd> |
| 1134 | <dt><code>XML_ERROR_FINISHED</code></dt> |
| 1135 | <dd>when the parser has already finished.</dd> |
| 1136 | <dt><code>XML_ERROR_SUSPEND_PE</code></dt> |
| 1137 | <dd>when suspending while parsing an external PE.</dd> |
| 1138 | </dl> |
| 1139 | |
| 1140 | <p>Since the stop/resume feature requires application support in the |
| 1141 | outer parsing loop, it is an error to call this function for a parser |
| 1142 | not being handled appropriately; see <a href= "#stop-resume" |
| 1143 | >Temporarily Stopping Parsing</a> for more information.</p> |
| 1144 | |
| 1145 | <p>When <code>resumable</code> is <code>XML_TRUE</code> then parsing |
| 1146 | is <em>suspended</em>, that is, <code><a href= "#XML_Parse" |
| 1147 | >XML_Parse</a></code> and <code><a href= "#XML_ParseBuffer" |
| 1148 | >XML_ParseBuffer</a></code> return <code>XML_STATUS_SUSPENDED</code>. |
| 1149 | Otherwise, parsing is <em>aborted</em>, that is, <code><a href= |
| 1150 | "#XML_Parse" >XML_Parse</a></code> and <code><a href= |
| 1151 | "#XML_ParseBuffer" >XML_ParseBuffer</a></code> return |
| 1152 | <code>XML_STATUS_ERROR</code> with error code |
| 1153 | <code>XML_ERROR_ABORTED</code>.</p> |
| 1154 | |
| 1155 | <p><strong>Note:</strong> |
| 1156 | This will be applied to the current parser instance only, that is, if |
| 1157 | there is a parent parser then it will continue parsing when the |
| 1158 | external entity reference handler returns. It is up to the |
| 1159 | implementation of that handler to call <code><a href= |
| 1160 | "#XML_StopParser" >XML_StopParser</a></code> on the parent parser |
| 1161 | (recursively), if one wants to stop parsing altogether.</p> |
| 1162 | |
| 1163 | <p>When suspended, parsing can be resumed by calling <code><a href= |
| 1164 | "#XML_ResumeParser" >XML_ResumeParser</a></code>.</p> |
| 1165 | |
| 1166 | <p>New in Expat 1.95.8.</p> |
| 1167 | </div> |
| 1168 | |
| 1169 | <pre class="fcndec" id="XML_ResumeParser"> |
| 1170 | enum XML_Status XMLCALL |
| 1171 | XML_ResumeParser(XML_Parser p); |
| 1172 | </pre> |
| 1173 | <div class="fcndef"> |
| 1174 | <p>Resumes parsing after it has been suspended with <code><a href= |
| 1175 | "#XML_StopParser" >XML_StopParser</a></code>. Must not be called from |
| 1176 | within a handler call-back. Returns same status codes as <code><a |
| 1177 | href= "#XML_Parse">XML_Parse</a></code> or <code><a href= |
| 1178 | "#XML_ParseBuffer" >XML_ParseBuffer</a></code>. An additional error |
| 1179 | code, <code>XML_ERROR_NOT_SUSPENDED</code>, will be returned if the |
| 1180 | parser was not currently suspended.</p> |
| 1181 | |
| 1182 | <p><strong>Note:</strong> |
| 1183 | This must be called on the most deeply nested child parser instance |
| 1184 | first, and on its parent parser only after the child parser has |
| 1185 | finished, to be applied recursively until the document entity's parser |
| 1186 | is restarted. That is, the parent parser will not resume by itself |
| 1187 | and it is up to the application to call <code><a href= |
| 1188 | "#XML_ResumeParser" >XML_ResumeParser</a></code> on it at the |
| 1189 | appropriate moment.</p> |
| 1190 | |
| 1191 | <p>New in Expat 1.95.8.</p> |
| 1192 | </div> |
| 1193 | |
| 1194 | <pre class="fcndec" id="XML_GetParsingStatus"> |
| 1195 | void XMLCALL |
| 1196 | XML_GetParsingStatus(XML_Parser p, |
| 1197 | XML_ParsingStatus *status); |
| 1198 | </pre> |
| 1199 | <pre class="signature"> |
| 1200 | enum XML_Parsing { |
| 1201 | XML_INITIALIZED, |
| 1202 | XML_PARSING, |
| 1203 | XML_FINISHED, |
| 1204 | XML_SUSPENDED |
| 1205 | }; |
| 1206 | |
| 1207 | typedef struct { |
| 1208 | enum XML_Parsing parsing; |
| 1209 | XML_Bool finalBuffer; |
| 1210 | } XML_ParsingStatus; |
| 1211 | </pre> |
| 1212 | <div class="fcndef"> |
| 1213 | <p>Returns status of parser with respect to being initialized, |
| 1214 | parsing, finished, or suspended, and whether the final buffer is being |
| 1215 | processed. The <code>status</code> parameter <em>must not</em> be |
| 1216 | NULL.</p> |
| 1217 | |
| 1218 | <p>New in Expat 1.95.8.</p> |
| 1219 | </div> |
| 1220 | |
| 1221 | |
| 1222 | <h3><a name="setting">Handler Setting</a></h3> |
| 1223 | |
| 1224 | <p>Although handlers are typically set prior to parsing and left alone, an |
| 1225 | application may choose to set or change the handler for a parsing event |
| 1226 | while the parse is in progress. For instance, your application may choose |
| 1227 | to ignore all text not descended from a <code>para</code> element. One |
| 1228 | way it could do this is to set the character handler when a para start tag |
| 1229 | is seen, and unset it for the corresponding end tag.</p> |
| 1230 | |
| 1231 | <p>A handler may be <em>unset</em> by providing a NULL pointer to the |
| 1232 | appropriate handler setter. None of the handler setting functions have |
| 1233 | a return value.</p> |
| 1234 | |
| 1235 | <p>Your handlers will be receiving strings in arrays of type |
| 1236 | <code>XML_Char</code>. This type is conditionally defined in expat.h as |
| 1237 | either <code>char</code>, <code>wchar_t</code> or <code>unsigned short</code>. |
| 1238 | The former implies UTF-8 encoding, the latter two imply UTF-16 encoding. |
| 1239 | Note that you'll receive them in this form independent of the original |
| 1240 | encoding of the document.</p> |
| 1241 | |
| 1242 | <div class="handler"> |
| 1243 | <pre class="setter" id="XML_SetStartElementHandler"> |
| 1244 | void XMLCALL |
| 1245 | XML_SetStartElementHandler(XML_Parser p, |
| 1246 | XML_StartElementHandler start); |
| 1247 | </pre> |
| 1248 | <pre class="signature"> |
| 1249 | typedef void |
| 1250 | (XMLCALL *XML_StartElementHandler)(void *userData, |
| 1251 | const XML_Char *name, |
| 1252 | const XML_Char **atts); |
| 1253 | </pre> |
| 1254 | <p>Set handler for start (and empty) tags. Attributes are passed to the start |
| 1255 | handler as a pointer to a vector of char pointers. Each attribute seen in |
| 1256 | a start (or empty) tag occupies 2 consecutive places in this vector: the |
| 1257 | attribute name followed by the attribute value. These pairs are terminated |
| 1258 | by a null pointer.</p> |
| 1259 | <p>Note that an empty tag generates a call to both start and end handlers |
| 1260 | (in that order).</p> |
| 1261 | </div> |
| 1262 | |
| 1263 | <div class="handler"> |
| 1264 | <pre class="setter" id="XML_SetEndElementHandler"> |
| 1265 | void XMLCALL |
| 1266 | XML_SetEndElementHandler(XML_Parser p, |
| 1267 | XML_EndElementHandler); |
| 1268 | </pre> |
| 1269 | <pre class="signature"> |
| 1270 | typedef void |
| 1271 | (XMLCALL *XML_EndElementHandler)(void *userData, |
| 1272 | const XML_Char *name); |
| 1273 | </pre> |
| 1274 | <p>Set handler for end (and empty) tags. As noted above, an empty tag |
| 1275 | generates a call to both start and end handlers.</p> |
| 1276 | </div> |
| 1277 | |
| 1278 | <div class="handler"> |
| 1279 | <pre class="setter" id="XML_SetElementHandler"> |
| 1280 | void XMLCALL |
| 1281 | XML_SetElementHandler(XML_Parser p, |
| 1282 | XML_StartElementHandler start, |
| 1283 | XML_EndElementHandler end); |
| 1284 | </pre> |
| 1285 | <p>Set handlers for start and end tags with one call.</p> |
| 1286 | </div> |
| 1287 | |
| 1288 | <div class="handler"> |
| 1289 | <pre class="setter" id="XML_SetCharacterDataHandler"> |
| 1290 | void XMLCALL |
| 1291 | XML_SetCharacterDataHandler(XML_Parser p, |
| 1292 | XML_CharacterDataHandler charhndl) |
| 1293 | </pre> |
| 1294 | <pre class="signature"> |
| 1295 | typedef void |
| 1296 | (XMLCALL *XML_CharacterDataHandler)(void *userData, |
| 1297 | const XML_Char *s, |
| 1298 | int len); |
| 1299 | </pre> |
| 1300 | <p>Set a text handler. The string your handler receives |
| 1301 | is <em>NOT nul-terminated</em>. You have to use the length argument |
| 1302 | to deal with the end of the string. A single block of contiguous text |
| 1303 | free of markup may still result in a sequence of calls to this handler. |
| 1304 | In other words, if you're searching for a pattern in the text, it may |
Elliott Hughes | d07d5a7 | 2009-09-25 16:04:37 -0700 | [diff] [blame] | 1305 | be split across calls to this handler. Note: Setting this handler to NULL |
| 1306 | may <em>NOT immediately</em> terminate call-backs if the parser is currently |
| 1307 | processing such a single block of contiguous markup-free text, as the parser |
| 1308 | will continue calling back until the end of the block is reached.</p> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 1309 | </div> |
| 1310 | |
| 1311 | <div class="handler"> |
| 1312 | <pre class="setter" id="XML_SetProcessingInstructionHandler"> |
| 1313 | void XMLCALL |
| 1314 | XML_SetProcessingInstructionHandler(XML_Parser p, |
| 1315 | XML_ProcessingInstructionHandler proc) |
| 1316 | </pre> |
| 1317 | <pre class="signature"> |
| 1318 | typedef void |
| 1319 | (XMLCALL *XML_ProcessingInstructionHandler)(void *userData, |
| 1320 | const XML_Char *target, |
| 1321 | const XML_Char *data); |
| 1322 | |
| 1323 | </pre> |
| 1324 | <p>Set a handler for processing instructions. The target is the first word |
| 1325 | in the processing instruction. The data is the rest of the characters in |
| 1326 | it after skipping all whitespace after the initial word.</p> |
| 1327 | </div> |
| 1328 | |
| 1329 | <div class="handler"> |
| 1330 | <pre class="setter" id="XML_SetCommentHandler"> |
| 1331 | void XMLCALL |
| 1332 | XML_SetCommentHandler(XML_Parser p, |
| 1333 | XML_CommentHandler cmnt) |
| 1334 | </pre> |
| 1335 | <pre class="signature"> |
| 1336 | typedef void |
| 1337 | (XMLCALL *XML_CommentHandler)(void *userData, |
| 1338 | const XML_Char *data); |
| 1339 | </pre> |
| 1340 | <p>Set a handler for comments. The data is all text inside the comment |
| 1341 | delimiters.</p> |
| 1342 | </div> |
| 1343 | |
| 1344 | <div class="handler"> |
| 1345 | <pre class="setter" id="XML_SetStartCdataSectionHandler"> |
| 1346 | void XMLCALL |
| 1347 | XML_SetStartCdataSectionHandler(XML_Parser p, |
| 1348 | XML_StartCdataSectionHandler start); |
| 1349 | </pre> |
| 1350 | <pre class="signature"> |
| 1351 | typedef void |
| 1352 | (XMLCALL *XML_StartCdataSectionHandler)(void *userData); |
| 1353 | </pre> |
| 1354 | <p>Set a handler that gets called at the beginning of a CDATA section.</p> |
| 1355 | </div> |
| 1356 | |
| 1357 | <div class="handler"> |
| 1358 | <pre class="setter" id="XML_SetEndCdataSectionHandler"> |
| 1359 | void XMLCALL |
| 1360 | XML_SetEndCdataSectionHandler(XML_Parser p, |
| 1361 | XML_EndCdataSectionHandler end); |
| 1362 | </pre> |
| 1363 | <pre class="signature"> |
| 1364 | typedef void |
| 1365 | (XMLCALL *XML_EndCdataSectionHandler)(void *userData); |
| 1366 | </pre> |
| 1367 | <p>Set a handler that gets called at the end of a CDATA section.</p> |
| 1368 | </div> |
| 1369 | |
| 1370 | <div class="handler"> |
| 1371 | <pre class="setter" id="XML_SetCdataSectionHandler"> |
| 1372 | void XMLCALL |
| 1373 | XML_SetCdataSectionHandler(XML_Parser p, |
| 1374 | XML_StartCdataSectionHandler start, |
| 1375 | XML_EndCdataSectionHandler end) |
| 1376 | </pre> |
| 1377 | <p>Sets both CDATA section handlers with one call.</p> |
| 1378 | </div> |
| 1379 | |
| 1380 | <div class="handler"> |
| 1381 | <pre class="setter" id="XML_SetDefaultHandler"> |
| 1382 | void XMLCALL |
| 1383 | XML_SetDefaultHandler(XML_Parser p, |
| 1384 | XML_DefaultHandler hndl) |
| 1385 | </pre> |
| 1386 | <pre class="signature"> |
| 1387 | typedef void |
| 1388 | (XMLCALL *XML_DefaultHandler)(void *userData, |
| 1389 | const XML_Char *s, |
| 1390 | int len); |
| 1391 | </pre> |
| 1392 | |
| 1393 | <p>Sets a handler for any characters in the document which wouldn't |
| 1394 | otherwise be handled. This includes both data for which no handlers |
| 1395 | can be set (like some kinds of DTD declarations) and data which could |
| 1396 | be reported but which currently has no handler set. The characters |
| 1397 | are passed exactly as they were present in the XML document except |
| 1398 | that they will be encoded in UTF-8 or UTF-16. Line boundaries are not |
| 1399 | normalized. Note that a byte order mark character is not passed to the |
| 1400 | default handler. There are no guarantees about how characters are |
| 1401 | divided between calls to the default handler: for example, a comment |
| 1402 | might be split between multiple calls. Setting the handler with |
| 1403 | this call has the side effect of turning off expansion of references |
| 1404 | to internally defined general entities. Instead these references are |
| 1405 | passed to the default handler.</p> |
| 1406 | |
| 1407 | <p>See also <code><a |
| 1408 | href="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p> |
| 1409 | </div> |
| 1410 | |
| 1411 | <div class="handler"> |
| 1412 | <pre class="setter" id="XML_SetDefaultHandlerExpand"> |
| 1413 | void XMLCALL |
| 1414 | XML_SetDefaultHandlerExpand(XML_Parser p, |
| 1415 | XML_DefaultHandler hndl) |
| 1416 | </pre> |
| 1417 | <pre class="signature"> |
| 1418 | typedef void |
| 1419 | (XMLCALL *XML_DefaultHandler)(void *userData, |
| 1420 | const XML_Char *s, |
| 1421 | int len); |
| 1422 | </pre> |
| 1423 | <p>This sets a default handler, but doesn't inhibit the expansion of |
| 1424 | internal entity references. The entity reference will not be passed |
| 1425 | to the default handler.</p> |
| 1426 | |
| 1427 | <p>See also <code><a |
| 1428 | href="#XML_DefaultCurrent">XML_DefaultCurrent</a></code>.</p> |
| 1429 | </div> |
| 1430 | |
| 1431 | <div class="handler"> |
| 1432 | <pre class="setter" id="XML_SetExternalEntityRefHandler"> |
| 1433 | void XMLCALL |
| 1434 | XML_SetExternalEntityRefHandler(XML_Parser p, |
| 1435 | XML_ExternalEntityRefHandler hndl) |
| 1436 | </pre> |
| 1437 | <pre class="signature"> |
| 1438 | typedef int |
| 1439 | (XMLCALL *XML_ExternalEntityRefHandler)(XML_Parser p, |
| 1440 | const XML_Char *context, |
| 1441 | const XML_Char *base, |
| 1442 | const XML_Char *systemId, |
| 1443 | const XML_Char *publicId); |
| 1444 | </pre> |
| 1445 | <p>Set an external entity reference handler. This handler is also |
| 1446 | called for processing an external DTD subset if parameter entity parsing |
| 1447 | is in effect. (See <a href="#XML_SetParamEntityParsing"> |
| 1448 | <code>XML_SetParamEntityParsing</code></a>.)</p> |
| 1449 | |
| 1450 | <p>The <code>context</code> parameter specifies the parsing context in |
| 1451 | the format expected by the <code>context</code> argument to <code><a |
| 1452 | href="#XML_ExternalEntityParserCreate" |
| 1453 | >XML_ExternalEntityParserCreate</a></code>. <code>code</code> is |
| 1454 | valid only until the handler returns, so if the referenced entity is |
| 1455 | to be parsed later, it must be copied. <code>context</code> is NULL |
| 1456 | only when the entity is a parameter entity, which is how one can |
| 1457 | differentiate between general and parameter entities.</p> |
| 1458 | |
| 1459 | <p>The <code>base</code> parameter is the base to use for relative |
| 1460 | system identifiers. It is set by <code><a |
| 1461 | href="#XML_SetBase">XML_SetBase</a></code> and may be NULL. The |
| 1462 | <code>publicId</code> parameter is the public id given in the entity |
| 1463 | declaration and may be NULL. <code>systemId</code> is the system |
| 1464 | identifier specified in the entity declaration and is never NULL.</p> |
| 1465 | |
| 1466 | <p>There are a couple of ways in which this handler differs from |
| 1467 | others. First, this handler returns a status indicator (an |
| 1468 | integer). <code>XML_STATUS_OK</code> should be returned for successful |
| 1469 | handling of the external entity reference. Returning |
| 1470 | <code>XML_STATUS_ERROR</code> indicates failure, and causes the |
| 1471 | calling parser to return an |
| 1472 | <code>XML_ERROR_EXTERNAL_ENTITY_HANDLING</code> error.</p> |
| 1473 | |
| 1474 | <p>Second, instead of having the user data as its first argument, it |
| 1475 | receives the parser that encountered the entity reference. This, along |
| 1476 | with the context parameter, may be used as arguments to a call to |
| 1477 | <code><a href= "#XML_ExternalEntityParserCreate" |
| 1478 | >XML_ExternalEntityParserCreate</a></code>. Using the returned |
| 1479 | parser, the body of the external entity can be recursively parsed.</p> |
| 1480 | |
| 1481 | <p>Since this handler may be called recursively, it should not be saving |
| 1482 | information into global or static variables.</p> |
| 1483 | </div> |
| 1484 | |
| 1485 | <pre class="fcndec" id="XML_SetExternalEntityRefHandlerArg"> |
| 1486 | void XMLCALL |
| 1487 | XML_SetExternalEntityRefHandlerArg(XML_Parser p, |
| 1488 | void *arg) |
| 1489 | </pre> |
| 1490 | <div class="fcndef"> |
| 1491 | <p>Set the argument passed to the ExternalEntityRefHandler. If |
| 1492 | <code>arg</code> is not NULL, it is the new value passed to the |
| 1493 | handler set using <code><a href="#XML_SetExternalEntityRefHandler" |
| 1494 | >XML_SetExternalEntityRefHandler</a></code>; if <code>arg</code> is |
| 1495 | NULL, the argument passed to the handler function will be the parser |
| 1496 | object itself.</p> |
| 1497 | |
| 1498 | <p><strong>Note:</strong> |
| 1499 | The type of <code>arg</code> and the type of the first argument to the |
| 1500 | ExternalEntityRefHandler do not match. This function takes a |
| 1501 | <code>void *</code> to be passed to the handler, while the handler |
| 1502 | accepts an <code>XML_Parser</code>. This is a historical accident, |
| 1503 | but will not be corrected before Expat 2.0 (at the earliest) to avoid |
| 1504 | causing compiler warnings for code that's known to work with this |
| 1505 | API. It is the responsibility of the application code to know the |
| 1506 | actual type of the argument passed to the handler and to manage it |
| 1507 | properly.</p> |
| 1508 | </div> |
| 1509 | |
| 1510 | <div class="handler"> |
| 1511 | <pre class="setter" id="XML_SetSkippedEntityHandler"> |
| 1512 | void XMLCALL |
| 1513 | XML_SetSkippedEntityHandler(XML_Parser p, |
| 1514 | XML_SkippedEntityHandler handler) |
| 1515 | </pre> |
| 1516 | <pre class="signature"> |
| 1517 | typedef void |
| 1518 | (XMLCALL *XML_SkippedEntityHandler)(void *userData, |
| 1519 | const XML_Char *entityName, |
| 1520 | int is_parameter_entity); |
| 1521 | </pre> |
| 1522 | <p>Set a skipped entity handler. This is called in two situations:</p> |
| 1523 | <ol> |
| 1524 | <li>An entity reference is encountered for which no declaration |
| 1525 | has been read <em>and</em> this is not an error.</li> |
| 1526 | <li>An internal entity reference is read, but not expanded, because |
| 1527 | <a href="#XML_SetDefaultHandler"><code>XML_SetDefaultHandler</code></a> |
| 1528 | has been called.</li> |
| 1529 | </ol> |
| 1530 | <p>The <code>is_parameter_entity</code> argument will be non-zero for |
| 1531 | a parameter entity and zero for a general entity.</p> <p>Note: skipped |
| 1532 | parameter entities in declarations and skipped general entities in |
| 1533 | attribute values cannot be reported, because the event would be out of |
| 1534 | sync with the reporting of the declarations or attribute values</p> |
| 1535 | </div> |
| 1536 | |
| 1537 | <div class="handler"> |
| 1538 | <pre class="setter" id="XML_SetUnknownEncodingHandler"> |
| 1539 | void XMLCALL |
| 1540 | XML_SetUnknownEncodingHandler(XML_Parser p, |
| 1541 | XML_UnknownEncodingHandler enchandler, |
| 1542 | void *encodingHandlerData) |
| 1543 | </pre> |
| 1544 | <pre class="signature"> |
| 1545 | typedef int |
| 1546 | (XMLCALL *XML_UnknownEncodingHandler)(void *encodingHandlerData, |
| 1547 | const XML_Char *name, |
| 1548 | XML_Encoding *info); |
| 1549 | |
| 1550 | typedef struct { |
| 1551 | int map[256]; |
| 1552 | void *data; |
| 1553 | int (XMLCALL *convert)(void *data, const char *s); |
| 1554 | void (XMLCALL *release)(void *data); |
| 1555 | } XML_Encoding; |
| 1556 | </pre> |
| 1557 | <p>Set a handler to deal with encodings other than the <a |
| 1558 | href="#builtin_encodings">built in set</a>. This should be done before |
| 1559 | <code><a href= "#XML_Parse" >XML_Parse</a></code> or <code><a href= |
| 1560 | "#XML_ParseBuffer" >XML_ParseBuffer</a></code> have been called on the |
| 1561 | given parser.</p> <p>If the handler knows how to deal with an encoding |
| 1562 | with the given name, it should fill in the <code>info</code> data |
| 1563 | structure and return <code>XML_STATUS_OK</code>. Otherwise it |
| 1564 | should return <code>XML_STATUS_ERROR</code>. The handler will be called |
| 1565 | at most once per parsed (external) entity. The optional application |
| 1566 | data pointer <code>encodingHandlerData</code> will be passed back to |
| 1567 | the handler.</p> |
| 1568 | |
Elliott Hughes | 7247294 | 2018-01-10 08:36:10 -0800 | [diff] [blame] | 1569 | <p>The map array contains information for every possible leading |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 1570 | byte in a byte sequence. If the corresponding value is >= 0, then it's |
| 1571 | a single byte sequence and the byte encodes that Unicode value. If the |
| 1572 | value is -1, then that byte is invalid as the initial byte in a sequence. |
| 1573 | If the value is -n, where n is an integer > 1, then n is the number of |
| 1574 | bytes in the sequence and the actual conversion is accomplished by a |
| 1575 | call to the function pointed at by convert. This function may return -1 |
| 1576 | if the sequence itself is invalid. The convert pointer may be null if |
| 1577 | there are only single byte codes. The data parameter passed to the convert |
| 1578 | function is the data pointer from <code>XML_Encoding</code>. The |
| 1579 | string s is <em>NOT</em> nul-terminated and points at the sequence of |
| 1580 | bytes to be converted.</p> |
| 1581 | |
| 1582 | <p>The function pointed at by <code>release</code> is called by the |
| 1583 | parser when it is finished with the encoding. It may be NULL.</p> |
| 1584 | </div> |
| 1585 | |
| 1586 | <div class="handler"> |
| 1587 | <pre class="setter" id="XML_SetStartNamespaceDeclHandler"> |
| 1588 | void XMLCALL |
| 1589 | XML_SetStartNamespaceDeclHandler(XML_Parser p, |
| 1590 | XML_StartNamespaceDeclHandler start); |
| 1591 | </pre> |
| 1592 | <pre class="signature"> |
| 1593 | typedef void |
| 1594 | (XMLCALL *XML_StartNamespaceDeclHandler)(void *userData, |
| 1595 | const XML_Char *prefix, |
| 1596 | const XML_Char *uri); |
| 1597 | </pre> |
| 1598 | <p>Set a handler to be called when a namespace is declared. Namespace |
| 1599 | declarations occur inside start tags. But the namespace declaration start |
| 1600 | handler is called before the start tag handler for each namespace declared |
| 1601 | in that start tag.</p> |
| 1602 | </div> |
| 1603 | |
| 1604 | <div class="handler"> |
| 1605 | <pre class="setter" id="XML_SetEndNamespaceDeclHandler"> |
| 1606 | void XMLCALL |
| 1607 | XML_SetEndNamespaceDeclHandler(XML_Parser p, |
| 1608 | XML_EndNamespaceDeclHandler end); |
| 1609 | </pre> |
| 1610 | <pre class="signature"> |
| 1611 | typedef void |
| 1612 | (XMLCALL *XML_EndNamespaceDeclHandler)(void *userData, |
| 1613 | const XML_Char *prefix); |
| 1614 | </pre> |
| 1615 | <p>Set a handler to be called when leaving the scope of a namespace |
| 1616 | declaration. This will be called, for each namespace declaration, |
| 1617 | after the handler for the end tag of the element in which the |
| 1618 | namespace was declared.</p> |
| 1619 | </div> |
| 1620 | |
| 1621 | <div class="handler"> |
| 1622 | <pre class="setter" id="XML_SetNamespaceDeclHandler"> |
| 1623 | void XMLCALL |
| 1624 | XML_SetNamespaceDeclHandler(XML_Parser p, |
| 1625 | XML_StartNamespaceDeclHandler start, |
| 1626 | XML_EndNamespaceDeclHandler end) |
| 1627 | </pre> |
| 1628 | <p>Sets both namespace declaration handlers with a single call.</p> |
| 1629 | </div> |
| 1630 | |
| 1631 | <div class="handler"> |
| 1632 | <pre class="setter" id="XML_SetXmlDeclHandler"> |
| 1633 | void XMLCALL |
| 1634 | XML_SetXmlDeclHandler(XML_Parser p, |
| 1635 | XML_XmlDeclHandler xmldecl); |
| 1636 | </pre> |
| 1637 | <pre class="signature"> |
| 1638 | typedef void |
| 1639 | (XMLCALL *XML_XmlDeclHandler)(void *userData, |
| 1640 | const XML_Char *version, |
| 1641 | const XML_Char *encoding, |
| 1642 | int standalone); |
| 1643 | </pre> |
| 1644 | <p>Sets a handler that is called for XML declarations and also for |
| 1645 | text declarations discovered in external entities. The way to |
| 1646 | distinguish is that the <code>version</code> parameter will be NULL |
| 1647 | for text declarations. The <code>encoding</code> parameter may be NULL |
| 1648 | for an XML declaration. The <code>standalone</code> argument will |
| 1649 | contain -1, 0, or 1 indicating respectively that there was no |
| 1650 | standalone parameter in the declaration, that it was given as no, or |
| 1651 | that it was given as yes.</p> |
| 1652 | </div> |
| 1653 | |
| 1654 | <div class="handler"> |
| 1655 | <pre class="setter" id="XML_SetStartDoctypeDeclHandler"> |
| 1656 | void XMLCALL |
| 1657 | XML_SetStartDoctypeDeclHandler(XML_Parser p, |
| 1658 | XML_StartDoctypeDeclHandler start); |
| 1659 | </pre> |
| 1660 | <pre class="signature"> |
| 1661 | typedef void |
| 1662 | (XMLCALL *XML_StartDoctypeDeclHandler)(void *userData, |
| 1663 | const XML_Char *doctypeName, |
| 1664 | const XML_Char *sysid, |
| 1665 | const XML_Char *pubid, |
| 1666 | int has_internal_subset); |
| 1667 | </pre> |
| 1668 | <p>Set a handler that is called at the start of a DOCTYPE declaration, |
| 1669 | before any external or internal subset is parsed. Both <code>sysid</code> |
| 1670 | and <code>pubid</code> may be NULL. The <code>has_internal_subset</code> |
| 1671 | will be non-zero if the DOCTYPE declaration has an internal subset.</p> |
| 1672 | </div> |
| 1673 | |
| 1674 | <div class="handler"> |
| 1675 | <pre class="setter" id="XML_SetEndDoctypeDeclHandler"> |
| 1676 | void XMLCALL |
| 1677 | XML_SetEndDoctypeDeclHandler(XML_Parser p, |
| 1678 | XML_EndDoctypeDeclHandler end); |
| 1679 | </pre> |
| 1680 | <pre class="signature"> |
| 1681 | typedef void |
| 1682 | (XMLCALL *XML_EndDoctypeDeclHandler)(void *userData); |
| 1683 | </pre> |
| 1684 | <p>Set a handler that is called at the end of a DOCTYPE declaration, |
| 1685 | after parsing any external subset.</p> |
| 1686 | </div> |
| 1687 | |
| 1688 | <div class="handler"> |
| 1689 | <pre class="setter" id="XML_SetDoctypeDeclHandler"> |
| 1690 | void XMLCALL |
| 1691 | XML_SetDoctypeDeclHandler(XML_Parser p, |
| 1692 | XML_StartDoctypeDeclHandler start, |
| 1693 | XML_EndDoctypeDeclHandler end); |
| 1694 | </pre> |
| 1695 | <p>Set both doctype handlers with one call.</p> |
| 1696 | </div> |
| 1697 | |
| 1698 | <div class="handler"> |
| 1699 | <pre class="setter" id="XML_SetElementDeclHandler"> |
| 1700 | void XMLCALL |
| 1701 | XML_SetElementDeclHandler(XML_Parser p, |
| 1702 | XML_ElementDeclHandler eldecl); |
| 1703 | </pre> |
| 1704 | <pre class="signature"> |
| 1705 | typedef void |
| 1706 | (XMLCALL *XML_ElementDeclHandler)(void *userData, |
| 1707 | const XML_Char *name, |
| 1708 | XML_Content *model); |
| 1709 | </pre> |
| 1710 | <pre class="signature"> |
| 1711 | enum XML_Content_Type { |
| 1712 | XML_CTYPE_EMPTY = 1, |
| 1713 | XML_CTYPE_ANY, |
| 1714 | XML_CTYPE_MIXED, |
| 1715 | XML_CTYPE_NAME, |
| 1716 | XML_CTYPE_CHOICE, |
| 1717 | XML_CTYPE_SEQ |
| 1718 | }; |
| 1719 | |
| 1720 | enum XML_Content_Quant { |
| 1721 | XML_CQUANT_NONE, |
| 1722 | XML_CQUANT_OPT, |
| 1723 | XML_CQUANT_REP, |
| 1724 | XML_CQUANT_PLUS |
| 1725 | }; |
| 1726 | |
| 1727 | typedef struct XML_cp XML_Content; |
| 1728 | |
| 1729 | struct XML_cp { |
| 1730 | enum XML_Content_Type type; |
| 1731 | enum XML_Content_Quant quant; |
| 1732 | const XML_Char * name; |
| 1733 | unsigned int numchildren; |
| 1734 | XML_Content * children; |
| 1735 | }; |
| 1736 | </pre> |
| 1737 | <p>Sets a handler for element declarations in a DTD. The handler gets |
| 1738 | called with the name of the element in the declaration and a pointer |
| 1739 | to a structure that contains the element model. It is the |
| 1740 | application's responsibility to free this data structure using |
| 1741 | <code><a href="#XML_FreeContentModel" |
| 1742 | >XML_FreeContentModel</a></code>.</p> |
| 1743 | |
| 1744 | <p>The <code>model</code> argument is the root of a tree of |
| 1745 | <code>XML_Content</code> nodes. If <code>type</code> equals |
| 1746 | <code>XML_CTYPE_EMPTY</code> or <code>XML_CTYPE_ANY</code>, then |
| 1747 | <code>quant</code> will be <code>XML_CQUANT_NONE</code>, and the other |
| 1748 | fields will be zero or NULL. If <code>type</code> is |
| 1749 | <code>XML_CTYPE_MIXED</code>, then <code>quant</code> will be |
| 1750 | <code>XML_CQUANT_NONE</code> or <code>XML_CQUANT_REP</code> and |
| 1751 | <code>numchildren</code> will contain the number of elements that are |
| 1752 | allowed to be mixed in and <code>children</code> points to an array of |
| 1753 | <code>XML_Content</code> structures that will all have type |
| 1754 | XML_CTYPE_NAME with no quantification. Only the root node can be type |
| 1755 | <code>XML_CTYPE_EMPTY</code>, <code>XML_CTYPE_ANY</code>, or |
| 1756 | <code>XML_CTYPE_MIXED</code>.</p> |
| 1757 | |
| 1758 | <p>For type <code>XML_CTYPE_NAME</code>, the <code>name</code> field |
| 1759 | points to the name and the <code>numchildren</code> and |
| 1760 | <code>children</code> fields will be zero and NULL. The |
| 1761 | <code>quant</code> field will indicate any quantifiers placed on the |
| 1762 | name.</p> |
| 1763 | |
| 1764 | <p>Types <code>XML_CTYPE_CHOICE</code> and <code>XML_CTYPE_SEQ</code> |
| 1765 | indicate a choice or sequence respectively. The |
| 1766 | <code>numchildren</code> field indicates how many nodes in the choice |
| 1767 | or sequence and <code>children</code> points to the nodes.</p> |
| 1768 | </div> |
| 1769 | |
| 1770 | <div class="handler"> |
| 1771 | <pre class="setter" id="XML_SetAttlistDeclHandler"> |
| 1772 | void XMLCALL |
| 1773 | XML_SetAttlistDeclHandler(XML_Parser p, |
| 1774 | XML_AttlistDeclHandler attdecl); |
| 1775 | </pre> |
| 1776 | <pre class="signature"> |
| 1777 | typedef void |
| 1778 | (XMLCALL *XML_AttlistDeclHandler)(void *userData, |
| 1779 | const XML_Char *elname, |
| 1780 | const XML_Char *attname, |
| 1781 | const XML_Char *att_type, |
| 1782 | const XML_Char *dflt, |
| 1783 | int isrequired); |
| 1784 | </pre> |
| 1785 | <p>Set a handler for attlist declarations in the DTD. This handler is |
| 1786 | called for <em>each</em> attribute. So a single attlist declaration |
| 1787 | with multiple attributes declared will generate multiple calls to this |
| 1788 | handler. The <code>elname</code> parameter returns the name of the |
| 1789 | element for which the attribute is being declared. The attribute name |
| 1790 | is in the <code>attname</code> parameter. The attribute type is in the |
| 1791 | <code>att_type</code> parameter. It is the string representing the |
| 1792 | type in the declaration with whitespace removed.</p> |
| 1793 | |
| 1794 | <p>The <code>dflt</code> parameter holds the default value. It will be |
| 1795 | NULL in the case of "#IMPLIED" or "#REQUIRED" attributes. You can |
| 1796 | distinguish these two cases by checking the <code>isrequired</code> |
| 1797 | parameter, which will be true in the case of "#REQUIRED" attributes. |
| 1798 | Attributes which are "#FIXED" will have also have a true |
| 1799 | <code>isrequired</code>, but they will have the non-NULL fixed value |
| 1800 | in the <code>dflt</code> parameter.</p> |
| 1801 | </div> |
| 1802 | |
| 1803 | <div class="handler"> |
| 1804 | <pre class="setter" id="XML_SetEntityDeclHandler"> |
| 1805 | void XMLCALL |
| 1806 | XML_SetEntityDeclHandler(XML_Parser p, |
| 1807 | XML_EntityDeclHandler handler); |
| 1808 | </pre> |
| 1809 | <pre class="signature"> |
| 1810 | typedef void |
| 1811 | (XMLCALL *XML_EntityDeclHandler)(void *userData, |
| 1812 | const XML_Char *entityName, |
| 1813 | int is_parameter_entity, |
| 1814 | const XML_Char *value, |
| 1815 | int value_length, |
| 1816 | const XML_Char *base, |
| 1817 | const XML_Char *systemId, |
| 1818 | const XML_Char *publicId, |
| 1819 | const XML_Char *notationName); |
| 1820 | </pre> |
| 1821 | <p>Sets a handler that will be called for all entity declarations. |
| 1822 | The <code>is_parameter_entity</code> argument will be non-zero in the |
| 1823 | case of parameter entities and zero otherwise.</p> |
| 1824 | |
| 1825 | <p>For internal entities (<code><!ENTITY foo "bar"></code>), |
| 1826 | <code>value</code> will be non-NULL and <code>systemId</code>, |
| 1827 | <code>publicId</code>, and <code>notationName</code> will all be NULL. |
| 1828 | The value string is <em>not</em> NULL terminated; the length is |
| 1829 | provided in the <code>value_length</code> parameter. Do not use |
| 1830 | <code>value_length</code> to test for internal entities, since it is |
| 1831 | legal to have zero-length values. Instead check for whether or not |
| 1832 | <code>value</code> is NULL.</p> <p>The <code>notationName</code> |
| 1833 | argument will have a non-NULL value only for unparsed entity |
| 1834 | declarations.</p> |
| 1835 | </div> |
| 1836 | |
| 1837 | <div class="handler"> |
| 1838 | <pre class="setter" id="XML_SetUnparsedEntityDeclHandler"> |
| 1839 | void XMLCALL |
| 1840 | XML_SetUnparsedEntityDeclHandler(XML_Parser p, |
| 1841 | XML_UnparsedEntityDeclHandler h) |
| 1842 | </pre> |
| 1843 | <pre class="signature"> |
| 1844 | typedef void |
| 1845 | (XMLCALL *XML_UnparsedEntityDeclHandler)(void *userData, |
| 1846 | const XML_Char *entityName, |
| 1847 | const XML_Char *base, |
| 1848 | const XML_Char *systemId, |
| 1849 | const XML_Char *publicId, |
| 1850 | const XML_Char *notationName); |
| 1851 | </pre> |
| 1852 | <p>Set a handler that receives declarations of unparsed entities. These |
| 1853 | are entity declarations that have a notation (NDATA) field:</p> |
| 1854 | |
| 1855 | <div id="eg"><pre> |
| 1856 | <!ENTITY logo SYSTEM "images/logo.gif" NDATA gif> |
| 1857 | </pre></div> |
| 1858 | <p>This handler is obsolete and is provided for backwards |
| 1859 | compatibility. Use instead <a href= "#XML_SetEntityDeclHandler" |
| 1860 | >XML_SetEntityDeclHandler</a>.</p> |
| 1861 | </div> |
| 1862 | |
| 1863 | <div class="handler"> |
| 1864 | <pre class="setter" id="XML_SetNotationDeclHandler"> |
| 1865 | void XMLCALL |
| 1866 | XML_SetNotationDeclHandler(XML_Parser p, |
| 1867 | XML_NotationDeclHandler h) |
| 1868 | </pre> |
| 1869 | <pre class="signature"> |
| 1870 | typedef void |
| 1871 | (XMLCALL *XML_NotationDeclHandler)(void *userData, |
| 1872 | const XML_Char *notationName, |
| 1873 | const XML_Char *base, |
| 1874 | const XML_Char *systemId, |
| 1875 | const XML_Char *publicId); |
| 1876 | </pre> |
| 1877 | <p>Set a handler that receives notation declarations.</p> |
| 1878 | </div> |
| 1879 | |
| 1880 | <div class="handler"> |
| 1881 | <pre class="setter" id="XML_SetNotStandaloneHandler"> |
| 1882 | void XMLCALL |
| 1883 | XML_SetNotStandaloneHandler(XML_Parser p, |
| 1884 | XML_NotStandaloneHandler h) |
| 1885 | </pre> |
| 1886 | <pre class="signature"> |
| 1887 | typedef int |
| 1888 | (XMLCALL *XML_NotStandaloneHandler)(void *userData); |
| 1889 | </pre> |
| 1890 | <p>Set a handler that is called if the document is not "standalone". |
| 1891 | This happens when there is an external subset or a reference to a |
| 1892 | parameter entity, but does not have standalone set to "yes" in an XML |
| 1893 | declaration. If this handler returns <code>XML_STATUS_ERROR</code>, |
| 1894 | then the parser will throw an <code>XML_ERROR_NOT_STANDALONE</code> |
| 1895 | error.</p> |
| 1896 | </div> |
| 1897 | |
| 1898 | <h3><a name="position">Parse position and error reporting functions</a></h3> |
| 1899 | |
| 1900 | <p>These are the functions you'll want to call when the parse |
| 1901 | functions return <code>XML_STATUS_ERROR</code> (a parse error has |
| 1902 | occurred), although the position reporting functions are useful outside |
| 1903 | of errors. The position reported is the byte position (in the original |
| 1904 | document or entity encoding) of the first of the sequence of |
| 1905 | characters that generated the current event (or the error that caused |
| 1906 | the parse functions to return <code>XML_STATUS_ERROR</code>.) The |
| 1907 | exceptions are callbacks trigged by declarations in the document |
| 1908 | prologue, in which case they exact position reported is somewhere in the |
| 1909 | relevant markup, but not necessarily as meaningful as for other |
| 1910 | events.</p> |
| 1911 | |
| 1912 | <p>The position reporting functions are accurate only outside of the |
| 1913 | DTD. In other words, they usually return bogus information when |
| 1914 | called from within a DTD declaration handler.</p> |
| 1915 | |
| 1916 | <pre class="fcndec" id="XML_GetErrorCode"> |
| 1917 | enum XML_Error XMLCALL |
| 1918 | XML_GetErrorCode(XML_Parser p); |
| 1919 | </pre> |
| 1920 | <div class="fcndef"> |
| 1921 | Return what type of error has occurred. |
| 1922 | </div> |
| 1923 | |
| 1924 | <pre class="fcndec" id="XML_ErrorString"> |
| 1925 | const XML_LChar * XMLCALL |
| 1926 | XML_ErrorString(enum XML_Error code); |
| 1927 | </pre> |
| 1928 | <div class="fcndef"> |
| 1929 | Return a string describing the error corresponding to code. |
| 1930 | The code should be one of the enums that can be returned from |
| 1931 | <code><a href= "#XML_GetErrorCode" >XML_GetErrorCode</a></code>. |
| 1932 | </div> |
| 1933 | |
| 1934 | <pre class="fcndec" id="XML_GetCurrentByteIndex"> |
| 1935 | XML_Index XMLCALL |
| 1936 | XML_GetCurrentByteIndex(XML_Parser p); |
| 1937 | </pre> |
| 1938 | <div class="fcndef"> |
| 1939 | Return the byte offset of the position. This always corresponds to |
| 1940 | the values returned by <code><a href= "#XML_GetCurrentLineNumber" |
| 1941 | >XML_GetCurrentLineNumber</a></code> and <code><a href= |
| 1942 | "#XML_GetCurrentColumnNumber" >XML_GetCurrentColumnNumber</a></code>. |
| 1943 | </div> |
| 1944 | |
| 1945 | <pre class="fcndec" id="XML_GetCurrentLineNumber"> |
| 1946 | XML_Size XMLCALL |
| 1947 | XML_GetCurrentLineNumber(XML_Parser p); |
| 1948 | </pre> |
| 1949 | <div class="fcndef"> |
| 1950 | Return the line number of the position. The first line is reported as |
| 1951 | <code>1</code>. |
| 1952 | </div> |
| 1953 | |
| 1954 | <pre class="fcndec" id="XML_GetCurrentColumnNumber"> |
| 1955 | XML_Size XMLCALL |
| 1956 | XML_GetCurrentColumnNumber(XML_Parser p); |
| 1957 | </pre> |
| 1958 | <div class="fcndef"> |
| 1959 | Return the offset, from the beginning of the current line, of |
| 1960 | the position. |
| 1961 | </div> |
| 1962 | |
| 1963 | <pre class="fcndec" id="XML_GetCurrentByteCount"> |
| 1964 | int XMLCALL |
| 1965 | XML_GetCurrentByteCount(XML_Parser p); |
| 1966 | </pre> |
| 1967 | <div class="fcndef"> |
| 1968 | Return the number of bytes in the current event. Returns |
| 1969 | <code>0</code> if the event is inside a reference to an internal |
| 1970 | entity and for the end-tag event for empty element tags (the later can |
| 1971 | be used to distinguish empty-element tags from empty elements using |
| 1972 | separate start and end tags). |
| 1973 | </div> |
| 1974 | |
| 1975 | <pre class="fcndec" id="XML_GetInputContext"> |
| 1976 | const char * XMLCALL |
| 1977 | XML_GetInputContext(XML_Parser p, |
| 1978 | int *offset, |
| 1979 | int *size); |
| 1980 | </pre> |
| 1981 | <div class="fcndef"> |
| 1982 | |
| 1983 | <p>Returns the parser's input buffer, sets the integer pointed at by |
| 1984 | <code>offset</code> to the offset within this buffer of the current |
| 1985 | parse position, and set the integer pointed at by <code>size</code> to |
| 1986 | the size of the returned buffer.</p> |
| 1987 | |
| 1988 | <p>This should only be called from within a handler during an active |
| 1989 | parse and the returned buffer should only be referred to from within |
| 1990 | the handler that made the call. This input buffer contains the |
| 1991 | untranslated bytes of the input.</p> |
| 1992 | |
| 1993 | <p>Only a limited amount of context is kept, so if the event |
| 1994 | triggering a call spans over a very large amount of input, the actual |
| 1995 | parse position may be before the beginning of the buffer.</p> |
| 1996 | |
| 1997 | <p>If <code>XML_CONTEXT_BYTES</code> is not defined, this will always |
| 1998 | return NULL.</p> |
| 1999 | </div> |
| 2000 | |
| 2001 | <h3><a name="miscellaneous">Miscellaneous functions</a></h3> |
| 2002 | |
| 2003 | <p>The functions in this section either obtain state information from |
Elliott Hughes | 7247294 | 2018-01-10 08:36:10 -0800 | [diff] [blame] | 2004 | the parser or can be used to dynamically set parser options.</p> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 2005 | |
| 2006 | <pre class="fcndec" id="XML_SetUserData"> |
| 2007 | void XMLCALL |
| 2008 | XML_SetUserData(XML_Parser p, |
| 2009 | void *userData); |
| 2010 | </pre> |
| 2011 | <div class="fcndef"> |
| 2012 | This sets the user data pointer that gets passed to handlers. It |
| 2013 | overwrites any previous value for this pointer. Note that the |
| 2014 | application is responsible for freeing the memory associated with |
| 2015 | <code>userData</code> when it is finished with the parser. So if you |
| 2016 | call this when there's already a pointer there, and you haven't freed |
| 2017 | the memory associated with it, then you've probably just leaked |
| 2018 | memory. |
| 2019 | </div> |
| 2020 | |
| 2021 | <pre class="fcndec" id="XML_GetUserData"> |
| 2022 | void * XMLCALL |
| 2023 | XML_GetUserData(XML_Parser p); |
| 2024 | </pre> |
| 2025 | <div class="fcndef"> |
| 2026 | This returns the user data pointer that gets passed to handlers. |
| 2027 | It is actually implemented as a macro. |
| 2028 | </div> |
| 2029 | |
| 2030 | <pre class="fcndec" id="XML_UseParserAsHandlerArg"> |
| 2031 | void XMLCALL |
| 2032 | XML_UseParserAsHandlerArg(XML_Parser p); |
| 2033 | </pre> |
| 2034 | <div class="fcndef"> |
| 2035 | After this is called, handlers receive the parser in their |
| 2036 | <code>userData</code> arguments. The user data can still be obtained |
| 2037 | using the <code><a href= "#XML_GetUserData" |
| 2038 | >XML_GetUserData</a></code> function. |
| 2039 | </div> |
| 2040 | |
| 2041 | <pre class="fcndec" id="XML_SetBase"> |
| 2042 | enum XML_Status XMLCALL |
| 2043 | XML_SetBase(XML_Parser p, |
| 2044 | const XML_Char *base); |
| 2045 | </pre> |
| 2046 | <div class="fcndef"> |
| 2047 | Set the base to be used for resolving relative URIs in system |
| 2048 | identifiers. The return value is <code>XML_STATUS_ERROR</code> if |
| 2049 | there's no memory to store base, otherwise it's |
| 2050 | <code>XML_STATUS_OK</code>. |
| 2051 | </div> |
| 2052 | |
| 2053 | <pre class="fcndec" id="XML_GetBase"> |
| 2054 | const XML_Char * XMLCALL |
| 2055 | XML_GetBase(XML_Parser p); |
| 2056 | </pre> |
| 2057 | <div class="fcndef"> |
| 2058 | Return the base for resolving relative URIs. |
| 2059 | </div> |
| 2060 | |
| 2061 | <pre class="fcndec" id="XML_GetSpecifiedAttributeCount"> |
| 2062 | int XMLCALL |
| 2063 | XML_GetSpecifiedAttributeCount(XML_Parser p); |
| 2064 | </pre> |
| 2065 | <div class="fcndef"> |
| 2066 | When attributes are reported to the start handler in the atts vector, |
| 2067 | attributes that were explicitly set in the element occur before any |
| 2068 | attributes that receive their value from default information in an |
| 2069 | ATTLIST declaration. This function returns the number of attributes |
| 2070 | that were explicitly set times two, thus giving the offset in the |
| 2071 | <code>atts</code> array passed to the start tag handler of the first |
| 2072 | attribute set due to defaults. It supplies information for the last |
| 2073 | call to a start handler. If called inside a start handler, then that |
| 2074 | means the current call. |
| 2075 | </div> |
| 2076 | |
| 2077 | <pre class="fcndec" id="XML_GetIdAttributeIndex"> |
| 2078 | int XMLCALL |
| 2079 | XML_GetIdAttributeIndex(XML_Parser p); |
| 2080 | </pre> |
| 2081 | <div class="fcndef"> |
| 2082 | Returns the index of the ID attribute passed in the atts array in the |
| 2083 | last call to <code><a href= "#XML_StartElementHandler" |
| 2084 | >XML_StartElementHandler</a></code>, or -1 if there is no ID |
| 2085 | attribute. If called inside a start handler, then that means the |
| 2086 | current call. |
| 2087 | </div> |
| 2088 | |
Elliott Hughes | 35e432d | 2012-09-09 14:23:38 -0700 | [diff] [blame] | 2089 | <pre class="fcndec" id="XML_GetAttributeInfo"> |
| 2090 | const XML_AttrInfo * XMLCALL |
| 2091 | XML_GetAttributeInfo(XML_Parser parser); |
| 2092 | </pre> |
| 2093 | <pre class="signature"> |
| 2094 | typedef struct { |
| 2095 | XML_Index nameStart; /* Offset to beginning of the attribute name. */ |
| 2096 | XML_Index nameEnd; /* Offset after the attribute name's last byte. */ |
| 2097 | XML_Index valueStart; /* Offset to beginning of the attribute value. */ |
| 2098 | XML_Index valueEnd; /* Offset after the attribute value's last byte. */ |
| 2099 | } XML_AttrInfo; |
| 2100 | </pre> |
| 2101 | <div class="fcndef"> |
| 2102 | Returns an array of <code>XML_AttrInfo</code> structures for the |
| 2103 | attribute/value pairs passed in the last call to the |
| 2104 | <code>XML_StartElementHandler</code> that were specified |
| 2105 | in the start-tag rather than defaulted. Each attribute/value pair counts |
| 2106 | as 1; thus the number of entries in the array is |
| 2107 | <code>XML_GetSpecifiedAttributeCount(parser) / 2</code>. |
| 2108 | </div> |
| 2109 | |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 2110 | <pre class="fcndec" id="XML_SetEncoding"> |
| 2111 | enum XML_Status XMLCALL |
| 2112 | XML_SetEncoding(XML_Parser p, |
| 2113 | const XML_Char *encoding); |
| 2114 | </pre> |
| 2115 | <div class="fcndef"> |
| 2116 | Set the encoding to be used by the parser. It is equivalent to |
| 2117 | passing a non-null encoding argument to the parser creation functions. |
| 2118 | It must not be called after <code><a href= "#XML_Parse" |
| 2119 | >XML_Parse</a></code> or <code><a href= "#XML_ParseBuffer" |
| 2120 | >XML_ParseBuffer</a></code> have been called on the given parser. |
| 2121 | Returns <code>XML_STATUS_OK</code> on success or |
| 2122 | <code>XML_STATUS_ERROR</code> on error. |
| 2123 | </div> |
| 2124 | |
| 2125 | <pre class="fcndec" id="XML_SetParamEntityParsing"> |
| 2126 | int XMLCALL |
| 2127 | XML_SetParamEntityParsing(XML_Parser p, |
| 2128 | enum XML_ParamEntityParsing code); |
| 2129 | </pre> |
| 2130 | <div class="fcndef"> |
| 2131 | This enables parsing of parameter entities, including the external |
| 2132 | parameter entity that is the external DTD subset, according to |
| 2133 | <code>code</code>. |
| 2134 | The choices for <code>code</code> are: |
| 2135 | <ul> |
| 2136 | <li><code>XML_PARAM_ENTITY_PARSING_NEVER</code></li> |
| 2137 | <li><code>XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE</code></li> |
| 2138 | <li><code>XML_PARAM_ENTITY_PARSING_ALWAYS</code></li> |
| 2139 | </ul> |
Elliott Hughes | 35e432d | 2012-09-09 14:23:38 -0700 | [diff] [blame] | 2140 | <b>Note:</b> If <code>XML_SetParamEntityParsing</code> is called after |
| 2141 | <code>XML_Parse</code> or <code>XML_ParseBuffer</code>, then it has |
| 2142 | no effect and will always return 0. |
| 2143 | </div> |
| 2144 | |
| 2145 | <pre class="fcndec" id="XML_SetHashSalt"> |
| 2146 | int XMLCALL |
| 2147 | XML_SetHashSalt(XML_Parser p, |
| 2148 | unsigned long hash_salt); |
| 2149 | </pre> |
| 2150 | <div class="fcndef"> |
| 2151 | Sets the hash salt to use for internal hash calculations. |
| 2152 | Helps in preventing DoS attacks based on predicting hash |
| 2153 | function behavior. In order to have an effect this must be called |
| 2154 | before parsing has started. Returns 1 if successful, 0 when called |
| 2155 | after <code>XML_Parse</code> or <code>XML_ParseBuffer</code>. |
Paul Duffin | cee2349 | 2016-05-04 10:42:31 +0100 | [diff] [blame] | 2156 | <p><b>Note:</b>This call is optional, as the parser will auto-generate |
Haibo Huang | 40a7191 | 2019-10-11 11:13:39 -0700 | [diff] [blame] | 2157 | a new random salt value if no value has been set at the start of parsing.</p> |
Paul Duffin | cee2349 | 2016-05-04 10:42:31 +0100 | [diff] [blame] | 2158 | <p><b>Note:</b>One should not call <code>XML_SetHashSalt</code> with a |
| 2159 | hash salt value of 0, as this value is used as sentinel value to indicate |
| 2160 | that <code>XML_SetHashSalt</code> has <b>not</b> been called. Consequently |
| 2161 | such a call will have no effect, even if it returns 1.</p> |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 2162 | </div> |
| 2163 | |
| 2164 | <pre class="fcndec" id="XML_UseForeignDTD"> |
| 2165 | enum XML_Error XMLCALL |
| 2166 | XML_UseForeignDTD(XML_Parser parser, XML_Bool useDTD); |
| 2167 | </pre> |
| 2168 | <div class="fcndef"> |
| 2169 | <p>This function allows an application to provide an external subset |
| 2170 | for the document type declaration for documents which do not specify |
| 2171 | an external subset of their own. For documents which specify an |
| 2172 | external subset in their DOCTYPE declaration, the application-provided |
| 2173 | subset will be ignored. If the document does not contain a DOCTYPE |
| 2174 | declaration at all and <code>useDTD</code> is true, the |
| 2175 | application-provided subset will be parsed, but the |
| 2176 | <code>startDoctypeDeclHandler</code> and |
| 2177 | <code>endDoctypeDeclHandler</code> functions, if set, will not be |
| 2178 | called. The setting of parameter entity parsing, controlled using |
| 2179 | <code><a href= "#XML_SetParamEntityParsing" |
| 2180 | >XML_SetParamEntityParsing</a></code>, will be honored.</p> |
| 2181 | |
| 2182 | <p>The application-provided external subset is read by calling the |
| 2183 | external entity reference handler set via <code><a href= |
| 2184 | "#XML_SetExternalEntityRefHandler" |
| 2185 | >XML_SetExternalEntityRefHandler</a></code> with both |
| 2186 | <code>publicId</code> and <code>systemId</code> set to NULL.</p> |
| 2187 | |
| 2188 | <p>If this function is called after parsing has begun, it returns |
| 2189 | <code>XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING</code> and ignores |
| 2190 | <code>useDTD</code>. If called when Expat has been compiled without |
| 2191 | DTD support, it returns |
| 2192 | <code>XML_ERROR_FEATURE_REQUIRES_XML_DTD</code>. Otherwise, it |
| 2193 | returns <code>XML_ERROR_NONE</code>.</p> |
| 2194 | |
| 2195 | <p><b>Note:</b> For the purpose of checking WFC: Entity Declared, passing |
| 2196 | <code>useDTD == XML_TRUE</code> will make the parser behave as if |
| 2197 | the document had a DTD with an external subset. This holds true even if |
| 2198 | the external entity reference handler returns without action.</p> |
| 2199 | </div> |
| 2200 | |
| 2201 | <pre class="fcndec" id="XML_SetReturnNSTriplet"> |
| 2202 | void XMLCALL |
| 2203 | XML_SetReturnNSTriplet(XML_Parser parser, |
| 2204 | int do_nst); |
| 2205 | </pre> |
| 2206 | <div class="fcndef"> |
| 2207 | <p> |
| 2208 | This function only has an effect when using a parser created with |
| 2209 | <code><a href= "#XML_ParserCreateNS" >XML_ParserCreateNS</a></code>, |
| 2210 | i.e. when namespace processing is in effect. The <code>do_nst</code> |
| 2211 | sets whether or not prefixes are returned with names qualified with a |
| 2212 | namespace prefix. If this function is called with <code>do_nst</code> |
| 2213 | non-zero, then afterwards namespace qualified names (that is qualified |
| 2214 | with a prefix as opposed to belonging to a default namespace) are |
| 2215 | returned as a triplet with the three parts separated by the namespace |
| 2216 | separator specified when the parser was created. The order of |
| 2217 | returned parts is URI, local name, and prefix.</p> <p>If |
| 2218 | <code>do_nst</code> is zero, then namespaces are reported in the |
| 2219 | default manner, URI then local_name separated by the namespace |
| 2220 | separator.</p> |
| 2221 | </div> |
| 2222 | |
| 2223 | <pre class="fcndec" id="XML_DefaultCurrent"> |
| 2224 | void XMLCALL |
| 2225 | XML_DefaultCurrent(XML_Parser parser); |
| 2226 | </pre> |
| 2227 | <div class="fcndef"> |
| 2228 | This can be called within a handler for a start element, end element, |
| 2229 | processing instruction or character data. It causes the corresponding |
| 2230 | markup to be passed to the default handler set by <code><a |
| 2231 | href="#XML_SetDefaultHandler" >XML_SetDefaultHandler</a></code> or |
| 2232 | <code><a href="#XML_SetDefaultHandlerExpand" |
| 2233 | >XML_SetDefaultHandlerExpand</a></code>. It does nothing if there is |
| 2234 | not a default handler. |
| 2235 | </div> |
| 2236 | |
| 2237 | <pre class="fcndec" id="XML_ExpatVersion"> |
| 2238 | XML_LChar * XMLCALL |
| 2239 | XML_ExpatVersion(); |
| 2240 | </pre> |
| 2241 | <div class="fcndef"> |
| 2242 | Return the library version as a string (e.g. <code>"expat_1.95.1"</code>). |
| 2243 | </div> |
| 2244 | |
| 2245 | <pre class="fcndec" id="XML_ExpatVersionInfo"> |
| 2246 | struct XML_Expat_Version XMLCALL |
| 2247 | XML_ExpatVersionInfo(); |
| 2248 | </pre> |
| 2249 | <pre class="signature"> |
| 2250 | typedef struct { |
| 2251 | int major; |
| 2252 | int minor; |
| 2253 | int micro; |
| 2254 | } XML_Expat_Version; |
| 2255 | </pre> |
| 2256 | <div class="fcndef"> |
| 2257 | Return the library version information as a structure. |
| 2258 | Some macros are also defined that support compile-time tests of the |
| 2259 | library version: |
| 2260 | <ul> |
| 2261 | <li><code>XML_MAJOR_VERSION</code></li> |
| 2262 | <li><code>XML_MINOR_VERSION</code></li> |
| 2263 | <li><code>XML_MICRO_VERSION</code></li> |
| 2264 | </ul> |
| 2265 | Testing these constants is currently the best way to determine if |
| 2266 | particular parts of the Expat API are available. |
| 2267 | </div> |
| 2268 | |
| 2269 | <pre class="fcndec" id="XML_GetFeatureList"> |
| 2270 | const XML_Feature * XMLCALL |
| 2271 | XML_GetFeatureList(); |
| 2272 | </pre> |
| 2273 | <pre class="signature"> |
| 2274 | enum XML_FeatureEnum { |
| 2275 | XML_FEATURE_END = 0, |
| 2276 | XML_FEATURE_UNICODE, |
| 2277 | XML_FEATURE_UNICODE_WCHAR_T, |
| 2278 | XML_FEATURE_DTD, |
| 2279 | XML_FEATURE_CONTEXT_BYTES, |
| 2280 | XML_FEATURE_MIN_SIZE, |
| 2281 | XML_FEATURE_SIZEOF_XML_CHAR, |
Elliott Hughes | d07d5a7 | 2009-09-25 16:04:37 -0700 | [diff] [blame] | 2282 | XML_FEATURE_SIZEOF_XML_LCHAR, |
| 2283 | XML_FEATURE_NS, |
| 2284 | XML_FEATURE_LARGE_SIZE |
The Android Open Source Project | b80e287 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 2285 | }; |
| 2286 | |
| 2287 | typedef struct { |
| 2288 | enum XML_FeatureEnum feature; |
| 2289 | XML_LChar *name; |
| 2290 | long int value; |
| 2291 | } XML_Feature; |
| 2292 | </pre> |
| 2293 | <div class="fcndef"> |
| 2294 | <p>Returns a list of "feature" records, providing details on how |
| 2295 | Expat was configured at compile time. Most applications should not |
| 2296 | need to worry about this, but this information is otherwise not |
| 2297 | available from Expat. This function allows code that does need to |
| 2298 | check these features to do so at runtime.</p> |
| 2299 | |
| 2300 | <p>The return value is an array of <code>XML_Feature</code>, |
| 2301 | terminated by a record with a <code>feature</code> of |
| 2302 | <code>XML_FEATURE_END</code> and <code>name</code> of NULL, |
| 2303 | identifying the feature-test macros Expat was compiled with. Since an |
| 2304 | application that requires this kind of information needs to determine |
| 2305 | the type of character the <code>name</code> points to, records for the |
| 2306 | <code>XML_FEATURE_SIZEOF_XML_CHAR</code> and |
| 2307 | <code>XML_FEATURE_SIZEOF_XML_LCHAR</code> will be located at the |
| 2308 | beginning of the list, followed by <code>XML_FEATURE_UNICODE</code> |
| 2309 | and <code>XML_FEATURE_UNICODE_WCHAR_T</code>, if they are present at |
| 2310 | all.</p> |
| 2311 | |
| 2312 | <p>Some features have an associated value. If there isn't an |
| 2313 | associated value, the <code>value</code> field is set to 0. At this |
| 2314 | time, the following features have been defined to have values:</p> |
| 2315 | |
| 2316 | <dl> |
| 2317 | <dt><code>XML_FEATURE_SIZEOF_XML_CHAR</code></dt> |
| 2318 | <dd>The number of bytes occupied by one <code>XML_Char</code> |
| 2319 | character.</dd> |
| 2320 | <dt><code>XML_FEATURE_SIZEOF_XML_LCHAR</code></dt> |
| 2321 | <dd>The number of bytes occupied by one <code>XML_LChar</code> |
| 2322 | character.</dd> |
| 2323 | <dt><code>XML_FEATURE_CONTEXT_BYTES</code></dt> |
| 2324 | <dd>The maximum number of characters of context which can be |
| 2325 | reported by <code><a href= "#XML_GetInputContext" |
| 2326 | >XML_GetInputContext</a></code>.</dd> |
| 2327 | </dl> |
| 2328 | </div> |
| 2329 | |
| 2330 | <pre class="fcndec" id="XML_FreeContentModel"> |
| 2331 | void XMLCALL |
| 2332 | XML_FreeContentModel(XML_Parser parser, XML_Content *model); |
| 2333 | </pre> |
| 2334 | <div class="fcndef"> |
| 2335 | Function to deallocate the <code>model</code> argument passed to the |
| 2336 | <code>XML_ElementDeclHandler</code> callback set using <code><a |
| 2337 | href="#XML_SetElementDeclHandler" >XML_ElementDeclHandler</a></code>. |
| 2338 | This function should not be used for any other purpose. |
| 2339 | </div> |
| 2340 | |
| 2341 | <p>The following functions allow external code to share the memory |
| 2342 | allocator an <code>XML_Parser</code> has been configured to use. This |
| 2343 | is especially useful for third-party libraries that interact with a |
| 2344 | parser object created by application code, or heavily layered |
| 2345 | applications. This can be essential when using dynamically loaded |
| 2346 | libraries which use different C standard libraries (this can happen on |
| 2347 | Windows, at least).</p> |
| 2348 | |
| 2349 | <pre class="fcndec" id="XML_MemMalloc"> |
| 2350 | void * XMLCALL |
| 2351 | XML_MemMalloc(XML_Parser parser, size_t size); |
| 2352 | </pre> |
| 2353 | <div class="fcndef"> |
| 2354 | Allocate <code>size</code> bytes of memory using the allocator the |
| 2355 | <code>parser</code> object has been configured to use. Returns a |
| 2356 | pointer to the memory or NULL on failure. Memory allocated in this |
| 2357 | way must be freed using <code><a href="#XML_MemFree" |
| 2358 | >XML_MemFree</a></code>. |
| 2359 | </div> |
| 2360 | |
| 2361 | <pre class="fcndec" id="XML_MemRealloc"> |
| 2362 | void * XMLCALL |
| 2363 | XML_MemRealloc(XML_Parser parser, void *ptr, size_t size); |
| 2364 | </pre> |
| 2365 | <div class="fcndef"> |
| 2366 | Allocate <code>size</code> bytes of memory using the allocator the |
| 2367 | <code>parser</code> object has been configured to use. |
| 2368 | <code>ptr</code> must point to a block of memory allocated by <code><a |
| 2369 | href="#XML_MemMalloc" >XML_MemMalloc</a></code> or |
| 2370 | <code>XML_MemRealloc</code>, or be NULL. This function tries to |
| 2371 | expand the block pointed to by <code>ptr</code> if possible. Returns |
| 2372 | a pointer to the memory or NULL on failure. On success, the original |
| 2373 | block has either been expanded or freed. On failure, the original |
| 2374 | block has not been freed; the caller is responsible for freeing the |
| 2375 | original block. Memory allocated in this way must be freed using |
| 2376 | <code><a href="#XML_MemFree" |
| 2377 | >XML_MemFree</a></code>. |
| 2378 | </div> |
| 2379 | |
| 2380 | <pre class="fcndec" id="XML_MemFree"> |
| 2381 | void XMLCALL |
| 2382 | XML_MemFree(XML_Parser parser, void *ptr); |
| 2383 | </pre> |
| 2384 | <div class="fcndef"> |
| 2385 | Free a block of memory pointed to by <code>ptr</code>. The block must |
| 2386 | have been allocated by <code><a href="#XML_MemMalloc" |
| 2387 | >XML_MemMalloc</a></code> or <code>XML_MemRealloc</code>, or be NULL. |
| 2388 | </div> |
| 2389 | |
| 2390 | <hr /> |
| 2391 | <p><a href="http://validator.w3.org/check/referer"><img |
| 2392 | src="valid-xhtml10.png" alt="Valid XHTML 1.0!" |
| 2393 | height="31" width="88" class="noborder" /></a></p> |
| 2394 | </div> |
| 2395 | </body> |
| 2396 | </html> |