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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 -->
14 </head>
15 <body>
17 <tr>
20 </tr>
21 <tr>
23 <td></td>
24 </tr>
25 </table>
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
31 other open-source XML parsers.</p>
33 <p>This library is the creation of James Clark, who's also given us
34 groff (an nroff look-alike), Jade (an implemention of ISO's DSSSL
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>
42 </p>
44 <p>The bulk of this document was originally commissioned as an article
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>
52 <hr />
54 <ul>
59 <ul>
61 <ul>
68 </ul>
69 </li>
71 <ul>
78 </ul>
79 </li>
81 <ul>
110 </ul>
111 </li>
113 <ul>
121 </ul>
122 </li>
124 <ul>
146 </ul>
147 </li>
148 </ul>
149 </li>
150 </ul>
152 <hr />
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>
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
167 <dl>
184 </dl>
188 section also describes in detail the parameters passed to the
189 different types of handlers.</p>
192 above functions (it doesn't need to set a character handler.) The
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
199 variable.</p>
202 int Depth;
204 void XMLCALL
205 start(void *data, const char *el, const char **attr) {
206 int i;
209 printf(" ");
211 printf("%s", el);
215 }
217 printf("\n");
218 Depth++;
219 } /* End of start handler */
220 </pre>
222 <p>The end tag simply does the bookkeeping work of decrementing
225 void XMLCALL
226 end(void *data, const char *el) {
227 Depth--;
228 } /* End of end handler */
229 </pre>
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
239 callbacks should be defined using this annotation.</p>
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
252 #ifndef XMLCALL
254 #define XMLCALL __cdecl
255 #elif defined(__GNUC__)
256 #define XMLCALL __attribute__((cdecl))
257 #else
258 #define XMLCALL
259 #endif
260 #endif
261 </pre>
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>
266 <hr />
269 <p>The Expat distribution comes as a compressed (with GNU gzip) tar
270 file. You may download the latest version from <a href=
272 unpacking this, cd into the directory. Then follow either the Win32
273 directions or Unix directions below.</p>
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
279 Developer Studio installed, then from Windows Explorer double-click on
280 "expat.dsp" in the lib directory and build and install in the usual
281 manner.</p>
283 <p>Alternatively, you may download the Win32 binary package that
288 <p>First you'll need to run the configure shell script in order to
289 configure the Makefiles and headers for your system.</p>
291 <p>If you're happy with all the defaults that configure picks for you,
292 and you have permission on your system to install into /usr/local, you
293 can install Expat with this sequence of commands:</p>
296 ./configure
297 make
298 make install
299 </pre>
301 <p>There are some options that you can provide to this script, but the
303 can find out all the options available by running configure with just
306 <p>By default, the configure script sets things up so that the library
310 library and header would get installed in
316 <p>Expat's feature set can be configured using a small number of
317 pre-processor definitions. The definition of this symbols does not
318 affect the set of entry points for Expat, only the behavior of the API
319 and the definition of character types in the case of
324 <dd>Include support for using and reporting DTD-based content. If
325 this is defined, default attribute values from an external DTD subset
326 are reported and attribute value normalization occurs based on the
327 type of attributes defined in the external subset. Without
328 this, Expat has a smaller memory footprint and can be faster, but will
329 not load external entities or process conditional sections. This does
330 not affect the set of functions available in the API.</dd>
335 specification is included.</dd>
338 <dd>When defined, character data reported to the application is
339 encoded in UTF-16 using wide characters of the type
346 short</code> is used. Defining this implies
351 integer types to be at least 64 bits in size. This is intended to support
352 processing of very large input streams, where the return values of
356 could overflow. It may not be supported by all compilers, and is turned
357 off by default.</dd>
360 <dd>The number of input bytes of markup context which the parser will
361 ensure are available for reporting via <code><a href=
363 normally set to 1024, and must be set to a positive interger. If this
364 is not defined, the input context will not be available and <code><a
366 always report NULL. Without this, Expat has a smaller memory
367 footprint and can be faster.</dd>
370 <dd>On Windows, this should be set if Expat is going to be linked
371 statically with the code that calls it; this is required to get all
372 the right MSVC magic annotations correct. This is ignored on other
373 platforms.</dd>
378 for reporting attribute byte offsets.</dd>
379 </dl>
381 <hr />
386 <p>Unless you installed Expat in a location not expected by your
387 compiler and linker, all you have to do to use Expat in your programs
389 in your files that make calls to it and to tell the linker that it
390 needs to link against the Expat library. On Unix systems, this would
392 you'll need to tell the compiler where to look for the Expat header
393 and the linker where to find the Expat library. You may also need to
394 take steps to tell the operating system where to find this library at
395 run time.</p>
397 <p>On a Unix-based system, here's what a Makefile might look like when
398 Expat is installed in a standard location:</p>
401 CC=cc
402 LDFLAGS=
403 LIBS= -lexpat
404 xmlapp: xmlapp.o
405 $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS)
406 </pre>
409 the Makefile would look like this:</p>
412 CC=cc
413 CFLAGS= -I/home/me/mystuff/include
414 LDFLAGS=
415 LIBS= -L/home/me/mystuff/lib -lexpat
416 xmlapp: xmlapp.o
417 $(CC) $(LDFLAGS) -o xmlapp xmlapp.o $(LIBS)
418 </pre>
420 <p>You'd also have to set the environment variable
423 LD_LIBRARY_PATH already has some directories in it) in order to run
424 your application.</p>
428 <p>As we saw in the example in the overview, the first step in parsing
429 an XML document with Expat is to create a parser object. There are <a
431 parser object. However, only two of these (<code><a href=
434 constructing a parser for a top-level document. The object returned
435 by these functions is an opaque pointer (i.e. "expat.h" declares it as
436 void *) to data with further internal structure. In order to free the
437 memory associated with this object you must call <code><a href=
440 parser, then your application is responsible for freeing it prior to
443 <p>The objects returned by the parser creation functions are good for
444 parsing only one XML document or external parsed entity. If your
445 application needs to parse many XML documents, then it needs to create
446 a parser object for each one. The best way to deal with this is to
447 create a higher level object that contains all the default
448 initialization you want for your parser objects.</p>
450 <p>Walking through a document hierarchy with a stream oriented parser
451 will require a good stack mechanism in order to keep track of current
452 context. For instance, to answer the simple question, "What element
453 does this text belong to?" requires a stack, since the parser may have
454 descended into other elements that are children of the current one and
455 has encountered this text on the way out.</p>
457 <p>The things you're likely to want to keep on a stack are the
458 currently opened element and it's attributes. You push this
459 information onto the stack in the start handler and you pop it off in
460 the end handler.</p>
462 <p>For some tasks, it is sufficient to just keep information on what
463 the depth of the stack is (or would be if you had one.) The outline
464 program shown above presents one example. Another such task would be
465 skipping over a complete element. When you see the start tag for the
466 element you want to skip, you set a skip flag and record the depth at
467 which the element started. When the end tag handler encounters the
468 same depth, the skipped element has ended and the flag may be
469 cleared. If you follow the convention that the root element starts at
470 1, then you can use the same variable for skip flag and skip
471 depth.</p>
474 void
475 init_info(Parseinfo *info) {
478 /* Other initializations here */
479 } /* End of init_info */
481 void XMLCALL
482 rawstart(void *data, const char *el, const char **attr) {
483 Parseinfo *inf = (Parseinfo *) data;
485 if (! inf->skip) {
486 if (should_skip(inf, el, attr)) {
488 }
489 else
490 start(inf, el, attr); /* This does rest of start handling */
491 }
493 inf->depth++;
494 } /* End of rawstart */
496 void XMLCALL
497 rawend(void *data, const char *el) {
498 Parseinfo *inf = (Parseinfo *) data;
500 inf->depth--;
502 if (! inf->skip)
503 end(inf, el); /* This does rest of end handling */
507 } /* End rawend */
508 </pre>
510 <p>Notice in the above example the difference in how depth is
511 manipulated in the start and end handlers. The end tag handler should
512 be the mirror image of the start tag handler. This is necessary to
513 properly model containment. Since, in the start tag handler, we
516 body. If we'd decided to increment it first thing in the start
517 handler, then we'd have had to decrement it last thing in the end
518 handler.</p>
522 <p>In order to be able to pass information between different handlers
523 without using globals, you'll need to define a data structure to hold
524 the shared variables. You can then tell Expat (with the <code><a href=
526 pointer to this structure to the handlers. This is the first
531 parser itself is passed. When the parser is passed, the user data may
535 <p>One common case where multiple calls to a single handler may need
536 to communicate using an application data structure is the case when
537 content passed to the character data handler (set by <code><a href=
538 "#XML_SetCharacterDataHandler"
540 common first-time mistake with any of the event-oriented interfaces to
541 an XML parser is to expect all the text contained in an element to be
542 reported by a single call to the character data handler. Expat, like
543 many other XML parsers, reports such data as a sequence of calls;
544 there's no way to know when the end of the sequence is reached until a
545 different callback is made. A buffer referenced by the user data
546 structure proves both an effective and convenient place to accumulate
547 character data.</p>
549 <!-- XXX example needed here -->
556 declaration, if present.</p>
558 <p>If an application needs to check the version number (to support
559 alternate processing), it should use the <code><a href=
561 set a handler that uses the information in the XML declaration to
562 determine what to do. This example shows how to check that only a
566 static int wrong_version;
567 static XML_Parser parser;
569 static void XMLCALL
570 xmldecl_handler(void *userData,
571 const XML_Char *version,
572 const XML_Char *encoding,
573 int standalone)
574 {
577 int i;
580 if (version[i] != Version_1_0[i]) {
581 wrong_version = 1;
582 /* also clear all other handlers: */
583 XML_SetCharacterDataHandler(parser, NULL);
584 ...
585 return;
586 }
587 }
588 ...
589 }
590 </pre>
596 performs namespace processing. Under namespace processing, Expat
598 which declare namespaces for the scope of the element in which they
599 occur. This means that your start handler will not see these
600 attributes. Your application can still be informed of these
601 declarations by setting namespace declaration handlers with <a href=
602 "#XML_SetNamespaceDeclHandler"
605 <p>Element type and attribute names that belong to a given namespace
606 are passed to the appropriate handler in expanded form. By default
607 this expanded form is a concatenation of the namespace URI, the
610 name (i.e. the part after the colon). Names with undeclared prefixes
611 are not well-formed when namespace processing is enabled, and will
612 trigger an error. Unprefixed attribute names are never expanded,
613 and unprefixed element names are only expanded when they are in the
614 scope of a default namespace.</p>
619 an explicit prefix is a concatenation of: URI, separator, local name,
620 separator, prefix.</p>
622 <p>You can set handlers for the start of a namespace declaration and
623 for the end of a scope of a declaration with the <code><a href=
625 function. The StartNamespaceDeclHandler is called prior to the start
626 tag handler and the EndNamespaceDeclHandler is called after the
627 corresponding end tag that ends the namespace's scope. The namespace
628 start handler gets passed the prefix and URI for the namespace. For a
629 default namespace declaration (xmlns='...'), the prefix will be null.
630 The URI will be null for the case where the default namespace is being
631 unset. The namespace end handler just gets the prefix for the closing
632 scope.</p>
634 <p>These handlers are called for each declaration. So if, for
635 instance, a start tag had three namespace declarations, then the
636 StartNamespaceDeclHandler would be called three times before the start
637 tag handler is called, once for each declaration.</p>
641 <p>While XML is based on Unicode, and every XML processor is required
643 other encodings may be declared in XML documents or entities. For the
644 main document, an XML declaration may contain an encoding
645 declaration:</p>
646 <pre>
648 </pre>
650 <p>External parsed entities may begin with a text declaration, which
651 looks like an XML declaration with just an encoding declaration:</p>
652 <pre>
654 </pre>
656 <p>With Expat, you may also specify an encoding at the time of
657 creating a parser. This is useful when the encoding information may
658 come from a source outside the document itself (like a higher level
659 protocol.)</p>
662 in Expat:</p>
663 <ul>
668 </ul>
670 <p>Anything else discovered in an encoding declaration or in the
671 protocol encoding specified in the parser constructor, triggers a call
674 structure. Your handler must fill in this structure and return
676 encoding. Otherwise the handler should return
678 to an optional application data structure that you may indicate when
679 you set the handler.</p>
681 <p>Expat places restrictions on character encodings that it can
683 include file:</p>
684 <ol>
685 <li>Every ASCII character that can appear in a well-formed XML document
686 must be represented by a single byte, and that byte must correspond to
687 it's ASCII encoding (except for the characters $@\^'{}~)</li>
689 <li>All characters encoded must have Unicode scalar values less than or
692 <li>No character may be encoded by more that one distinct sequence of
693 bytes</li>
694 </ol>
697 correspond to the 1st byte of an encoding sequence. If the value in
698 the array for a byte is zero or positive, then the byte is a single
699 byte encoding that encodes the Unicode scalar value contained in the
700 array. A -1 in this array indicates a malformed byte. If the value is
702 sequence respectively. Multi-byte sequences are sent to the convert
704 function should return the Unicode scalar value for the sequence or -1
705 if the sequence is malformed.</p>
707 <p>One pitfall that novice Expat users are likely to fall into is that
708 although Expat may accept input in various encodings, the strings that
710 (depending on how Expat was compiled). Your application is responsible
711 for any translation of these strings into other encodings.</p>
715 <p>Expat does not read or parse external entities directly. Note that
716 any external DTD is a special case of an external entity. If you've
718 references are silently ignored. Otherwise, it calls your handler with
719 the information needed to read and parse the external entity.</p>
721 <p>Your handler isn't actually responsible for parsing the entity, but
722 it is responsible for creating a subsidiary parser with <code><a href=
723 "#XML_ExternalEntityParserCreate"
726 other data structures initialized from the parent parser. You may then
729 parser. Since external entities my refer to other external entities,
730 your handler should be prepared to be called recursively.</p>
734 <p>In order to parse parameter entities, before starting the parse,
737 arguments:</p>
738 <dl>
742 <dd>Parse parameter entites and the external subset unless
746 </dl>
748 <p>In order to read an external DTD, you also have to set an external
749 entity reference handler as described above.</p>
754 parsing temporarily from within a handler function, even if more data
755 has already been passed into the parser. Applications for this
756 include</p>
758 <ul>
762 <li>Delaying further processing until additional information is
763 available from some other source.</li>
765 <li>Adjusting processor load as task priorities shift within an
766 application.</li>
768 <li>Stopping parsing completely (simply free or reset the parser
769 instead of resuming in the outer parsing loop). This can be useful
770 if a application-domain error is found in the XML being parsed or if
771 the result of the parse is determined not to be useful after
772 all.</li>
773 </ul>
775 <p>To take advantage of this feature, the main parsing loop of an
776 application needs to support this specifically. It cannot be
777 supported with a parsing loop compatible with Expat 1.95.7 or
778 earlier (though existing loops will continue to work without
779 supporting the stop/resume feature).</p>
781 <p>An application that uses this feature for a single parser will have
782 the rough structure (in pseudo-code):</p>
785 fd = open_input()
786 p = create_parser()
788 if parse_xml(p, fd) {
789 /* suspended */
791 int suspended = 1;
793 while (suspended) {
794 do_something_else()
795 if ready_to_resume() {
796 suspended = continue_parsing(p, fd);
797 }
798 }
799 }
800 </pre>
802 <p>An application that may resume any of several parsers based on
803 input (either from the XML being parsed or some other source) will
804 certainly have more interesting control structures.</p>
807 function mentioned in the pseudo-code above:</p>
810 #define BUFF_SIZE 10240
812 /* Parse a document from the open file descriptor 'fd' until the parse
813 is complete (the document has been completely parsed, or there's
814 been an error), or the parse is stopped. Return non-zero when
815 the parse is merely suspended.
816 */
817 int
818 parse_xml(XML_Parser p, int fd)
819 {
820 for (;;) {
821 int last_chunk;
822 int bytes_read;
823 enum XML_Status status;
825 void *buff = XML_GetBuffer(p, BUFF_SIZE);
826 if (buff == NULL) {
827 /* handle error... */
828 return 0;
829 }
830 bytes_read = read(fd, buff, BUFF_SIZE);
832 /* handle error... */
833 return 0;
834 }
835 status = XML_ParseBuffer(p, bytes_read, bytes_read == 0);
836 switch (status) {
837 case XML_STATUS_ERROR:
838 /* handle error... */
839 return 0;
840 case XML_STATUS_SUSPENDED:
841 return 1;
842 }
843 if (bytes_read == 0)
844 return 0;
845 }
846 }
847 </pre>
850 somewhat simpler, since it only need deal with the return code from
853 function:</p>
856 /* Continue parsing a document which had been suspended. The 'p' and
857 'fd' arguments are the same as passed to parse_xml(). Return
858 non-zero when the parse is suspended.
859 */
860 int
861 continue_parsing(XML_Parser p, int fd)
862 {
863 enum XML_Status status = XML_ResumeParser(p);
864 switch (status) {
865 case XML_STATUS_ERROR:
866 /* handle error... */
867 return 0;
868 case XML_ERROR_NOT_SUSPENDED:
869 /* handle error... */
870 return 0;.
871 case XML_STATUS_SUSPENDED:
872 return 1;
873 }
874 return parse_xml(p, fd);
875 }
876 </pre>
878 <p>Now that we've seen what a mess the top-level parsing loop can
879 become, what have we gained? Very simply, we can now use the <code><a
881 parsing, without having to go to great lengths to avoid additional
882 processing that we're expecting to ignore. As a bonus, we get to stop
884 ready.</p>
888 takes two arguments; the parser being stopped and a flag indicating
889 whether the parse can be resumed in the future.</p>
891 <!-- XXX really need more here -->
894 <hr />
895 <!-- ================================================================ -->
902 XML_Parser XMLCALL
903 XML_ParserCreate(const XML_Char *encoding);
904 </pre>
906 Construct a new parser. If encoding is non-null, it specifies a
907 character encoding to use for the document. This overrides the document
908 encoding declaration. There are four built-in encodings:
909 <ul>
914 </ul>
915 Any other value will invoke a call to the UnknownEncodingHandler.
916 </div>
919 XML_Parser XMLCALL
920 XML_ParserCreateNS(const XML_Char *encoding,
921 XML_Char sep);
922 </pre>
924 Constructs a new parser that has namespace processing in effect. Namespace
925 expanded element names and attribute names are returned as a concatenation
928 of an URI. Since Expat does not check namespace URIs for conformance, the
929 only safe choice for a namespace separator is a character that is illegal
933 the local part will be concatenated without any separator - this is intended
934 to support RDF processors. It is a programming error to use the null separator
938 XML_Parser XMLCALL
939 XML_ParserCreate_MM(const XML_Char *encoding,
940 const XML_Memory_Handling_Suite *ms,
941 const XML_Char *sep);
942 </pre>
944 typedef struct {
945 void *(XMLCALL *malloc_fcn)(size_t size);
946 void *(XMLCALL *realloc_fcn)(void *ptr, size_t size);
947 void (XMLCALL *free_fcn)(void *ptr);
948 } XML_Memory_Handling_Suite;
949 </pre>
951 <p>Construct a new parser using the suite of memory handling functions
954 non NULL, then namespace processing is enabled in the created parser
955 and the character pointed at by sep is used as the separator between
956 the namespace URI and the local part of the name.</p>
957 </div>
960 XML_Parser XMLCALL
961 XML_ExternalEntityParserCreate(XML_Parser p,
962 const XML_Char *context,
963 const XML_Char *encoding);
964 </pre>
967 general entity. Context is the context argument passed in a call to a
968 ExternalEntityRefHandler. Other state information such as handlers,
969 user data, namespace processing is inherited from the parser passed as
970 the 1st argument. So you shouldn't need to call any of the behavior
971 changing functions on this parser (unless you want it to act
972 differently than the parent parser).
973 </div>
976 void XMLCALL
977 XML_ParserFree(XML_Parser p);
978 </pre>
980 Free memory used by the parser. Your application is responsible for
982 </div>
985 XML_Bool XMLCALL
986 XML_ParserReset(XML_Parser p,
987 const XML_Char *encoding);
988 </pre>
990 Clean up the memory structures maintained by the parser so that it may
992 ready to start parsing a new document. All handlers are cleared from
993 the parser, except for the unknownEncodingHandler. The parser's external
994 state is re-initialized except for the values of ns and ns_triplets.
995 This function may not be used on a parser created using <code><a href=
1000 </div>
1007 XML_GetBuffer</a></code> must not be called from within a handler
1008 unless they operate on a separate parser instance, that is, one that
1009 did not call the handler. For example, it is OK to call the parsing
1011 if they apply to the parser created by
1016 should be considerably less than the maximum value for an integer,
1017 as it could create an integer overflow situation if the added
1018 lengths of a buffer and the unprocessed portion of the previous buffer
1019 exceed the maximum integer value. Input data at the end of a buffer
1020 will remain unprocessed if it is part of an XML token for which the
1021 end is not part of that buffer.</p>
1024 enum XML_Status XMLCALL
1025 XML_Parse(XML_Parser p,
1026 const char *s,
1027 int len,
1028 int isFinal);
1029 </pre>
1031 enum XML_Status {
1032 XML_STATUS_ERROR = 0,
1033 XML_STATUS_OK = 1
1034 };
1035 </pre>
1038 containing part (or perhaps all) of the document. The number of bytes of s
1044 piece of the document. Frequently, the last piece is empty (i.e.
1048 </div>
1051 enum XML_Status XMLCALL
1052 XML_ParseBuffer(XML_Parser p,
1053 int len,
1054 int isFinal);
1055 </pre>
1058 except in this case Expat provides the buffer. By obtaining the
1061 copying of the input.
1062 </div>
1065 void * XMLCALL
1066 XML_GetBuffer(XML_Parser p,
1067 int len);
1068 </pre>
1071 into. A NULL value is returned if Expat can't allocate enough memory for
1072 this buffer. This has to be called prior to every call to
1074 typical use would look like this:
1077 for (;;) {
1078 int bytes_read;
1079 void *buff = XML_GetBuffer(p, BUFF_SIZE);
1080 if (buff == NULL) {
1081 /* handle error */
1082 }
1084 bytes_read = read(docfd, buff, BUFF_SIZE);
1086 /* handle error */
1087 }
1089 if (! XML_ParseBuffer(p, bytes_read, bytes_read == 0)) {
1090 /* handle parse error */
1091 }
1093 if (bytes_read == 0)
1094 break;
1095 }
1096 </pre>
1097 </div>
1100 enum XML_Status XMLCALL
1101 XML_StopParser(XML_Parser p,
1102 XML_Bool resumable);
1103 </pre>
1111 call-backs may still follow because they would otherwise get
1112 lost, including
1113 <ul>
1114 <li> the end element handler for empty elements when stopped in the
1115 start element handler,</li>
1116 <li> the end namespace declaration handler when stopped in the end
1117 element handler,</li>
1118 <li> the character data handler when stopped in the character data handler
1119 while making multiple call-backs on a contiguous chunk of characters,</li>
1120 </ul>
1121 and possibly others.</p>
1123 <p>This can be called from most handlers, including DTD related
1124 call-backs, except when parsing an external parameter entity and
1128 are:</p>
1129 <dl>
1136 </dl>
1138 <p>Since the stop/resume feature requires application support in the
1139 outer parsing loop, it is an error to call this function for a parser
1154 This will be applied to the current parser instance only, that is, if
1155 there is a parent parser then it will continue parsing when the
1156 external entity reference handler returns. It is up to the
1157 implementation of that handler to call <code><a href=
1159 (recursively), if one wants to stop parsing altogether.</p>
1165 </div>
1168 enum XML_Status XMLCALL
1169 XML_ResumeParser(XML_Parser p);
1170 </pre>
1174 within a handler call-back. Returns same status codes as <code><a
1178 parser was not currently suspended.</p>
1181 This must be called on the most deeply nested child parser instance
1182 first, and on its parent parser only after the child parser has
1183 finished, to be applied recursively until the document entity's parser
1184 is restarted. That is, the parent parser will not resume by itself
1185 and it is up to the application to call <code><a href=
1187 appropriate moment.</p>
1190 </div>
1193 void XMLCALL
1194 XML_GetParsingStatus(XML_Parser p,
1195 XML_ParsingStatus *status);
1196 </pre>
1198 enum XML_Parsing {
1199 XML_INITIALIZED,
1200 XML_PARSING,
1201 XML_FINISHED,
1202 XML_SUSPENDED
1203 };
1205 typedef struct {
1206 enum XML_Parsing parsing;
1207 XML_Bool finalBuffer;
1208 } XML_ParsingStatus;
1209 </pre>
1211 <p>Returns status of parser with respect to being initialized,
1212 parsing, finished, or suspended, and whether the final buffer is being
1214 NULL.</p>
1217 </div>
1222 <p>Although handlers are typically set prior to parsing and left alone, an
1223 application may choose to set or change the handler for a parsing event
1224 while the parse is in progress. For instance, your application may choose
1226 way it could do this is to set the character handler when a para start tag
1227 is seen, and unset it for the corresponding end tag.</p>
1230 appropriate handler setter. None of the handler setting functions have
1231 a return value.</p>
1233 <p>Your handlers will be receiving strings in arrays of type
1237 Note that you'll receive them in this form independent of the original
1238 encoding of the document.</p>
1242 void XMLCALL
1243 XML_SetStartElementHandler(XML_Parser p,
1244 XML_StartElementHandler start);
1245 </pre>
1247 typedef void
1248 (XMLCALL *XML_StartElementHandler)(void *userData,
1249 const XML_Char *name,
1250 const XML_Char **atts);
1251 </pre>
1252 <p>Set handler for start (and empty) tags. Attributes are passed to the start
1253 handler as a pointer to a vector of char pointers. Each attribute seen in
1254 a start (or empty) tag occupies 2 consecutive places in this vector: the
1255 attribute name followed by the attribute value. These pairs are terminated
1256 by a null pointer.</p>
1257 <p>Note that an empty tag generates a call to both start and end handlers
1258 (in that order).</p>
1259 </div>
1263 void XMLCALL
1264 XML_SetEndElementHandler(XML_Parser p,
1265 XML_EndElementHandler);
1266 </pre>
1268 typedef void
1269 (XMLCALL *XML_EndElementHandler)(void *userData,
1270 const XML_Char *name);
1271 </pre>
1272 <p>Set handler for end (and empty) tags. As noted above, an empty tag
1273 generates a call to both start and end handlers.</p>
1274 </div>
1278 void XMLCALL
1279 XML_SetElementHandler(XML_Parser p,
1280 XML_StartElementHandler start,
1281 XML_EndElementHandler end);
1282 </pre>
1284 </div>
1288 void XMLCALL
1289 XML_SetCharacterDataHandler(XML_Parser p,
1290 XML_CharacterDataHandler charhndl)
1291 </pre>
1293 typedef void
1294 (XMLCALL *XML_CharacterDataHandler)(void *userData,
1295 const XML_Char *s,
1296 int len);
1297 </pre>
1298 <p>Set a text handler. The string your handler receives
1300 to deal with the end of the string. A single block of contiguous text
1301 free of markup may still result in a sequence of calls to this handler.
1302 In other words, if you're searching for a pattern in the text, it may
1303 be split across calls to this handler. Note: Setting this handler to NULL
1305 processing such a single block of contiguous markup-free text, as the parser
1306 will continue calling back until the end of the block is reached.</p>
1307 </div>
1311 void XMLCALL
1312 XML_SetProcessingInstructionHandler(XML_Parser p,
1313 XML_ProcessingInstructionHandler proc)
1314 </pre>
1316 typedef void
1317 (XMLCALL *XML_ProcessingInstructionHandler)(void *userData,
1318 const XML_Char *target,
1319 const XML_Char *data);
1321 </pre>
1322 <p>Set a handler for processing instructions. The target is the first word
1323 in the processing instruction. The data is the rest of the characters in
1324 it after skipping all whitespace after the initial word.</p>
1325 </div>
1329 void XMLCALL
1330 XML_SetCommentHandler(XML_Parser p,
1331 XML_CommentHandler cmnt)
1332 </pre>
1334 typedef void
1335 (XMLCALL *XML_CommentHandler)(void *userData,
1336 const XML_Char *data);
1337 </pre>
1338 <p>Set a handler for comments. The data is all text inside the comment
1339 delimiters.</p>
1340 </div>
1344 void XMLCALL
1345 XML_SetStartCdataSectionHandler(XML_Parser p,
1346 XML_StartCdataSectionHandler start);
1347 </pre>
1349 typedef void
1350 (XMLCALL *XML_StartCdataSectionHandler)(void *userData);
1351 </pre>
1353 </div>
1357 void XMLCALL
1358 XML_SetEndCdataSectionHandler(XML_Parser p,
1359 XML_EndCdataSectionHandler end);
1360 </pre>
1362 typedef void
1363 (XMLCALL *XML_EndCdataSectionHandler)(void *userData);
1364 </pre>
1366 </div>
1370 void XMLCALL
1371 XML_SetCdataSectionHandler(XML_Parser p,
1372 XML_StartCdataSectionHandler start,
1373 XML_EndCdataSectionHandler end)
1374 </pre>
1376 </div>
1380 void XMLCALL
1381 XML_SetDefaultHandler(XML_Parser p,
1382 XML_DefaultHandler hndl)
1383 </pre>
1385 typedef void
1386 (XMLCALL *XML_DefaultHandler)(void *userData,
1387 const XML_Char *s,
1388 int len);
1389 </pre>
1391 <p>Sets a handler for any characters in the document which wouldn't
1392 otherwise be handled. This includes both data for which no handlers
1393 can be set (like some kinds of DTD declarations) and data which could
1394 be reported but which currently has no handler set. The characters
1395 are passed exactly as they were present in the XML document except
1397 normalized. Note that a byte order mark character is not passed to the
1398 default handler. There are no guarantees about how characters are
1399 divided between calls to the default handler: for example, a comment
1400 might be split between multiple calls. Setting the handler with
1401 this call has the side effect of turning off expansion of references
1402 to internally defined general entities. Instead these references are
1403 passed to the default handler.</p>
1407 </div>
1411 void XMLCALL
1412 XML_SetDefaultHandlerExpand(XML_Parser p,
1413 XML_DefaultHandler hndl)
1414 </pre>
1416 typedef void
1417 (XMLCALL *XML_DefaultHandler)(void *userData,
1418 const XML_Char *s,
1419 int len);
1420 </pre>
1421 <p>This sets a default handler, but doesn't inhibit the expansion of
1422 internal entity references. The entity reference will not be passed
1423 to the default handler.</p>
1427 </div>
1431 void XMLCALL
1432 XML_SetExternalEntityRefHandler(XML_Parser p,
1433 XML_ExternalEntityRefHandler hndl)
1434 </pre>
1436 typedef int
1437 (XMLCALL *XML_ExternalEntityRefHandler)(XML_Parser p,
1438 const XML_Char *context,
1439 const XML_Char *base,
1440 const XML_Char *systemId,
1441 const XML_Char *publicId);
1442 </pre>
1443 <p>Set an external entity reference handler. This handler is also
1444 called for processing an external DTD subset if parameter entity parsing
1452 valid only until the handler returns, so if the referenced entity is
1454 only when the entity is a parameter entity, which is how one can
1455 differentiate between general and parameter entities.</p>
1458 system identifiers. It is set by <code><a
1462 identifier specified in the entity declaration and is never NULL.</p>
1464 <p>There are a couple of ways in which this handler differs from
1465 others. First, this handler returns a status indicator (an
1467 handling of the external entity reference. Returning
1469 calling parser to return an
1472 <p>Second, instead of having the user data as its first argument, it
1473 receives the parser that encountered the entity reference. This, along
1474 with the context parameter, may be used as arguments to a call to
1477 parser, the body of the external entity can be recursively parsed.</p>
1479 <p>Since this handler may be called recursively, it should not be saving
1480 information into global or static variables.</p>
1481 </div>
1484 void XMLCALL
1485 XML_SetExternalEntityRefHandlerArg(XML_Parser p,
1486 void *arg)
1487 </pre>
1489 <p>Set the argument passed to the ExternalEntityRefHandler. If
1493 NULL, the argument passed to the handler function will be the parser
1494 object itself.</p>
1498 ExternalEntityRefHandler do not match. This function takes a
1501 but will not be corrected before Expat 2.0 (at the earliest) to avoid
1502 causing compiler warnings for code that's known to work with this
1503 API. It is the responsibility of the application code to know the
1504 actual type of the argument passed to the handler and to manage it
1505 properly.</p>
1506 </div>
1510 void XMLCALL
1511 XML_SetSkippedEntityHandler(XML_Parser p,
1512 XML_SkippedEntityHandler handler)
1513 </pre>
1515 typedef void
1516 (XMLCALL *XML_SkippedEntityHandler)(void *userData,
1517 const XML_Char *entityName,
1518 int is_parameter_entity);
1519 </pre>
1521 <ol>
1522 <li>An entity reference is encountered for which no declaration
1524 <li>An internal entity reference is read, but not expanded, because
1526 has been called.</li>
1527 </ol>
1529 a parameter entity and zero for a general entity.</p> <p>Note: skipped
1530 parameter entities in declarations and skipped general entities in
1531 attribute values cannot be reported, because the event would be out of
1532 sync with the reporting of the declarations or attribute values</p>
1533 </div>
1537 void XMLCALL
1538 XML_SetUnknownEncodingHandler(XML_Parser p,
1539 XML_UnknownEncodingHandler enchandler,
1540 void *encodingHandlerData)
1541 </pre>
1543 typedef int
1544 (XMLCALL *XML_UnknownEncodingHandler)(void *encodingHandlerData,
1545 const XML_Char *name,
1546 XML_Encoding *info);
1548 typedef struct {
1549 int map[256];
1550 void *data;
1551 int (XMLCALL *convert)(void *data, const char *s);
1552 void (XMLCALL *release)(void *data);
1553 } XML_Encoding;
1554 </pre>
1559 given parser.</p> <p>If the handler knows how to deal with an encoding
1563 at most once per parsed (external) entity. The optional application
1565 the handler.</p>
1567 <p>The map array contains information for every possible possible leading
1569 a single byte sequence and the byte encodes that Unicode value. If the
1570 value is -1, then that byte is invalid as the initial byte in a sequence.
1572 bytes in the sequence and the actual conversion is accomplished by a
1573 call to the function pointed at by convert. This function may return -1
1574 if the sequence itself is invalid. The convert pointer may be null if
1575 there are only single byte codes. The data parameter passed to the convert
1578 bytes to be converted.</p>
1581 parser when it is finished with the encoding. It may be NULL.</p>
1582 </div>
1586 void XMLCALL
1587 XML_SetStartNamespaceDeclHandler(XML_Parser p,
1588 XML_StartNamespaceDeclHandler start);
1589 </pre>
1591 typedef void
1592 (XMLCALL *XML_StartNamespaceDeclHandler)(void *userData,
1593 const XML_Char *prefix,
1594 const XML_Char *uri);
1595 </pre>
1596 <p>Set a handler to be called when a namespace is declared. Namespace
1597 declarations occur inside start tags. But the namespace declaration start
1598 handler is called before the start tag handler for each namespace declared
1599 in that start tag.</p>
1600 </div>
1604 void XMLCALL
1605 XML_SetEndNamespaceDeclHandler(XML_Parser p,
1606 XML_EndNamespaceDeclHandler end);
1607 </pre>
1609 typedef void
1610 (XMLCALL *XML_EndNamespaceDeclHandler)(void *userData,
1611 const XML_Char *prefix);
1612 </pre>
1613 <p>Set a handler to be called when leaving the scope of a namespace
1614 declaration. This will be called, for each namespace declaration,
1615 after the handler for the end tag of the element in which the
1616 namespace was declared.</p>
1617 </div>
1621 void XMLCALL
1622 XML_SetNamespaceDeclHandler(XML_Parser p,
1623 XML_StartNamespaceDeclHandler start,
1624 XML_EndNamespaceDeclHandler end)
1625 </pre>
1627 </div>
1631 void XMLCALL
1632 XML_SetXmlDeclHandler(XML_Parser p,
1633 XML_XmlDeclHandler xmldecl);
1634 </pre>
1636 typedef void
1637 (XMLCALL *XML_XmlDeclHandler)(void *userData,
1638 const XML_Char *version,
1639 const XML_Char *encoding,
1640 int standalone);
1641 </pre>
1642 <p>Sets a handler that is called for XML declarations and also for
1643 text declarations discovered in external entities. The way to
1648 standalone parameter in the declaration, that it was given as no, or
1649 that it was given as yes.</p>
1650 </div>
1654 void XMLCALL
1655 XML_SetStartDoctypeDeclHandler(XML_Parser p,
1656 XML_StartDoctypeDeclHandler start);
1657 </pre>
1659 typedef void
1660 (XMLCALL *XML_StartDoctypeDeclHandler)(void *userData,
1661 const XML_Char *doctypeName,
1662 const XML_Char *sysid,
1663 const XML_Char *pubid,
1664 int has_internal_subset);
1665 </pre>
1666 <p>Set a handler that is called at the start of a DOCTYPE declaration,
1669 will be non-zero if the DOCTYPE declaration has an internal subset.</p>
1670 </div>
1674 void XMLCALL
1675 XML_SetEndDoctypeDeclHandler(XML_Parser p,
1676 XML_EndDoctypeDeclHandler end);
1677 </pre>
1679 typedef void
1680 (XMLCALL *XML_EndDoctypeDeclHandler)(void *userData);
1681 </pre>
1682 <p>Set a handler that is called at the end of a DOCTYPE declaration,
1683 after parsing any external subset.</p>
1684 </div>
1688 void XMLCALL
1689 XML_SetDoctypeDeclHandler(XML_Parser p,
1690 XML_StartDoctypeDeclHandler start,
1691 XML_EndDoctypeDeclHandler end);
1692 </pre>
1694 </div>
1698 void XMLCALL
1699 XML_SetElementDeclHandler(XML_Parser p,
1700 XML_ElementDeclHandler eldecl);
1701 </pre>
1703 typedef void
1704 (XMLCALL *XML_ElementDeclHandler)(void *userData,
1705 const XML_Char *name,
1706 XML_Content *model);
1707 </pre>
1709 enum XML_Content_Type {
1710 XML_CTYPE_EMPTY = 1,
1711 XML_CTYPE_ANY,
1712 XML_CTYPE_MIXED,
1713 XML_CTYPE_NAME,
1714 XML_CTYPE_CHOICE,
1715 XML_CTYPE_SEQ
1716 };
1718 enum XML_Content_Quant {
1719 XML_CQUANT_NONE,
1720 XML_CQUANT_OPT,
1721 XML_CQUANT_REP,
1722 XML_CQUANT_PLUS
1723 };
1725 typedef struct XML_cp XML_Content;
1727 struct XML_cp {
1728 enum XML_Content_Type type;
1729 enum XML_Content_Quant quant;
1730 const XML_Char * name;
1731 unsigned int numchildren;
1732 XML_Content * children;
1733 };
1734 </pre>
1735 <p>Sets a handler for element declarations in a DTD. The handler gets
1736 called with the name of the element in the declaration and a pointer
1737 to a structure that contains the element model. It is the
1738 application's responsibility to free this data structure using
1752 XML_CTYPE_NAME with no quantification. Only the root node can be type
1760 name.</p>
1763 indicate a choice or sequence respectively. The
1766 </div>
1770 void XMLCALL
1771 XML_SetAttlistDeclHandler(XML_Parser p,
1772 XML_AttlistDeclHandler attdecl);
1773 </pre>
1775 typedef void
1776 (XMLCALL *XML_AttlistDeclHandler)(void *userData,
1777 const XML_Char *elname,
1778 const XML_Char *attname,
1779 const XML_Char *att_type,
1780 const XML_Char *dflt,
1781 int isrequired);
1782 </pre>
1783 <p>Set a handler for attlist declarations in the DTD. This handler is
1785 with multiple attributes declared will generate multiple calls to this
1787 element for which the attribute is being declared. The attribute name
1790 type in the declaration with whitespace removed.</p>
1795 parameter, which will be true in the case of "#REQUIRED" attributes.
1796 Attributes which are "#FIXED" will have also have a true
1799 </div>
1803 void XMLCALL
1804 XML_SetEntityDeclHandler(XML_Parser p,
1805 XML_EntityDeclHandler handler);
1806 </pre>
1808 typedef void
1809 (XMLCALL *XML_EntityDeclHandler)(void *userData,
1810 const XML_Char *entityName,
1811 int is_parameter_entity,
1812 const XML_Char *value,
1813 int value_length,
1814 const XML_Char *base,
1815 const XML_Char *systemId,
1816 const XML_Char *publicId,
1817 const XML_Char *notationName);
1818 </pre>
1819 <p>Sets a handler that will be called for all entity declarations.
1821 case of parameter entities and zero otherwise.</p>
1829 legal to have zero-length values. Instead check for whether or not
1831 argument will have a non-NULL value only for unparsed entity
1832 declarations.</p>
1833 </div>
1837 void XMLCALL
1838 XML_SetUnparsedEntityDeclHandler(XML_Parser p,
1839 XML_UnparsedEntityDeclHandler h)
1840 </pre>
1842 typedef void
1843 (XMLCALL *XML_UnparsedEntityDeclHandler)(void *userData,
1844 const XML_Char *entityName,
1845 const XML_Char *base,
1846 const XML_Char *systemId,
1847 const XML_Char *publicId,
1848 const XML_Char *notationName);
1849 </pre>
1850 <p>Set a handler that receives declarations of unparsed entities. These
1851 are entity declarations that have a notation (NDATA) field:</p>
1855 </pre></div>
1856 <p>This handler is obsolete and is provided for backwards
1859 </div>
1863 void XMLCALL
1864 XML_SetNotationDeclHandler(XML_Parser p,
1865 XML_NotationDeclHandler h)
1866 </pre>
1868 typedef void
1869 (XMLCALL *XML_NotationDeclHandler)(void *userData,
1870 const XML_Char *notationName,
1871 const XML_Char *base,
1872 const XML_Char *systemId,
1873 const XML_Char *publicId);
1874 </pre>
1876 </div>
1880 void XMLCALL
1881 XML_SetNotStandaloneHandler(XML_Parser p,
1882 XML_NotStandaloneHandler h)
1883 </pre>
1885 typedef int
1886 (XMLCALL *XML_NotStandaloneHandler)(void *userData);
1887 </pre>
1889 This happens when there is an external subset or a reference to a
1890 parameter entity, but does not have standalone set to "yes" in an XML
1893 error.</p>
1894 </div>
1898 <p>These are the functions you'll want to call when the parse
1900 occurred), although the position reporting functions are useful outside
1901 of errors. The position reported is the byte position (in the original
1902 document or entity encoding) of the first of the sequence of
1903 characters that generated the current event (or the error that caused
1905 exceptions are callbacks trigged by declarations in the document
1906 prologue, in which case they exact position reported is somewhere in the
1907 relevant markup, but not necessarily as meaningful as for other
1908 events.</p>
1910 <p>The position reporting functions are accurate only outside of the
1911 DTD. In other words, they usually return bogus information when
1912 called from within a DTD declaration handler.</p>
1915 enum XML_Error XMLCALL
1916 XML_GetErrorCode(XML_Parser p);
1917 </pre>
1919 Return what type of error has occurred.
1920 </div>
1923 const XML_LChar * XMLCALL
1924 XML_ErrorString(enum XML_Error code);
1925 </pre>
1927 Return a string describing the error corresponding to code.
1928 The code should be one of the enums that can be returned from
1930 </div>
1933 XML_Index XMLCALL
1934 XML_GetCurrentByteIndex(XML_Parser p);
1935 </pre>
1937 Return the byte offset of the position. This always corresponds to
1941 </div>
1944 XML_Size XMLCALL
1945 XML_GetCurrentLineNumber(XML_Parser p);
1946 </pre>
1948 Return the line number of the position. The first line is reported as
1950 </div>
1953 XML_Size XMLCALL
1954 XML_GetCurrentColumnNumber(XML_Parser p);
1955 </pre>
1957 Return the offset, from the beginning of the current line, of
1958 the position.
1959 </div>
1962 int XMLCALL
1963 XML_GetCurrentByteCount(XML_Parser p);
1964 </pre>
1966 Return the number of bytes in the current event. Returns
1968 entity and for the end-tag event for empty element tags (the later can
1969 be used to distinguish empty-element tags from empty elements using
1970 separate start and end tags).
1971 </div>
1974 const char * XMLCALL
1975 XML_GetInputContext(XML_Parser p,
1976 int *offset,
1977 int *size);
1978 </pre>
1981 <p>Returns the parser's input buffer, sets the integer pointed at by
1984 the size of the returned buffer.</p>
1986 <p>This should only be called from within a handler during an active
1987 parse and the returned buffer should only be referred to from within
1988 the handler that made the call. This input buffer contains the
1989 untranslated bytes of the input.</p>
1991 <p>Only a limited amount of context is kept, so if the event
1992 triggering a call spans over a very large amount of input, the actual
1993 parse position may be before the beginning of the buffer.</p>
1996 return NULL.</p>
1997 </div>
2001 <p>The functions in this section either obtain state information from
2002 the parser or can be used to dynamicly set parser options.</p>
2005 void XMLCALL
2006 XML_SetUserData(XML_Parser p,
2007 void *userData);
2008 </pre>
2010 This sets the user data pointer that gets passed to handlers. It
2011 overwrites any previous value for this pointer. Note that the
2012 application is responsible for freeing the memory associated with
2014 call this when there's already a pointer there, and you haven't freed
2015 the memory associated with it, then you've probably just leaked
2016 memory.
2017 </div>
2020 void * XMLCALL
2021 XML_GetUserData(XML_Parser p);
2022 </pre>
2024 This returns the user data pointer that gets passed to handlers.
2025 It is actually implemented as a macro.
2026 </div>
2029 void XMLCALL
2030 XML_UseParserAsHandlerArg(XML_Parser p);
2031 </pre>
2033 After this is called, handlers receive the parser in their
2037 </div>
2040 enum XML_Status XMLCALL
2041 XML_SetBase(XML_Parser p,
2042 const XML_Char *base);
2043 </pre>
2045 Set the base to be used for resolving relative URIs in system
2047 there's no memory to store base, otherwise it's
2049 </div>
2052 const XML_Char * XMLCALL
2053 XML_GetBase(XML_Parser p);
2054 </pre>
2056 Return the base for resolving relative URIs.
2057 </div>
2060 int XMLCALL
2061 XML_GetSpecifiedAttributeCount(XML_Parser p);
2062 </pre>
2064 When attributes are reported to the start handler in the atts vector,
2065 attributes that were explicitly set in the element occur before any
2066 attributes that receive their value from default information in an
2067 ATTLIST declaration. This function returns the number of attributes
2068 that were explicitly set times two, thus giving the offset in the
2070 attribute set due to defaults. It supplies information for the last
2071 call to a start handler. If called inside a start handler, then that
2072 means the current call.
2073 </div>
2076 int XMLCALL
2077 XML_GetIdAttributeIndex(XML_Parser p);
2078 </pre>
2080 Returns the index of the ID attribute passed in the atts array in the
2083 attribute. If called inside a start handler, then that means the
2084 current call.
2085 </div>
2088 const XML_AttrInfo * XMLCALL
2089 XML_GetAttributeInfo(XML_Parser parser);
2090 </pre>
2092 typedef struct {
2093 XML_Index nameStart; /* Offset to beginning of the attribute name. */
2094 XML_Index nameEnd; /* Offset after the attribute name's last byte. */
2095 XML_Index valueStart; /* Offset to beginning of the attribute value. */
2096 XML_Index valueEnd; /* Offset after the attribute value's last byte. */
2097 } XML_AttrInfo;
2098 </pre>
2101 attribute/value pairs passed in the last call to the
2103 in the start-tag rather than defaulted. Each attribute/value pair counts
2104 as 1; thus the number of entries in the array is
2106 </div>
2109 enum XML_Status XMLCALL
2110 XML_SetEncoding(XML_Parser p,
2111 const XML_Char *encoding);
2112 </pre>
2114 Set the encoding to be used by the parser. It is equivalent to
2115 passing a non-null encoding argument to the parser creation functions.
2121 </div>
2124 int XMLCALL
2125 XML_SetParamEntityParsing(XML_Parser p,
2126 enum XML_ParamEntityParsing code);
2127 </pre>
2129 This enables parsing of parameter entities, including the external
2130 parameter entity that is the external DTD subset, according to
2133 <ul>
2137 </ul>
2140 no effect and will always return 0.
2141 </div>
2144 int XMLCALL
2145 XML_SetHashSalt(XML_Parser p,
2146 unsigned long hash_salt);
2147 </pre>
2149 Sets the hash salt to use for internal hash calculations.
2150 Helps in preventing DoS attacks based on predicting hash
2151 function behavior. In order to have an effect this must be called
2155 random salt value if no value has been set at the start of parsing.</p>
2156 </div>
2159 enum XML_Error XMLCALL
2160 XML_UseForeignDTD(XML_Parser parser, XML_Bool useDTD);
2161 </pre>
2163 <p>This function allows an application to provide an external subset
2164 for the document type declaration for documents which do not specify
2165 an external subset of their own. For documents which specify an
2166 external subset in their DOCTYPE declaration, the application-provided
2167 subset will be ignored. If the document does not contain a DOCTYPE
2169 application-provided subset will be parsed, but the
2172 called. The setting of parameter entity parsing, controlled using
2176 <p>The application-provided external subset is read by calling the
2177 external entity reference handler set via <code><a href=
2178 "#XML_SetExternalEntityRefHandler"
2182 <p>If this function is called after parsing has begun, it returns
2185 DTD support, it returns
2191 the document had a DTD with an external subset. This holds true even if
2192 the external entity reference handler returns without action.</p>
2193 </div>
2196 void XMLCALL
2197 XML_SetReturnNSTriplet(XML_Parser parser,
2198 int do_nst);
2199 </pre>
2201 <p>
2202 This function only has an effect when using a parser created with
2205 sets whether or not prefixes are returned with names qualified with a
2207 non-zero, then afterwards namespace qualified names (that is qualified
2208 with a prefix as opposed to belonging to a default namespace) are
2209 returned as a triplet with the three parts separated by the namespace
2210 separator specified when the parser was created. The order of
2211 returned parts is URI, local name, and prefix.</p> <p>If
2213 default manner, URI then local_name separated by the namespace
2214 separator.</p>
2215 </div>
2218 void XMLCALL
2219 XML_DefaultCurrent(XML_Parser parser);
2220 </pre>
2222 This can be called within a handler for a start element, end element,
2223 processing instruction or character data. It causes the corresponding
2224 markup to be passed to the default handler set by <code><a
2228 not a default handler.
2229 </div>
2232 XML_LChar * XMLCALL
2233 XML_ExpatVersion();
2234 </pre>
2237 </div>
2240 struct XML_Expat_Version XMLCALL
2241 XML_ExpatVersionInfo();
2242 </pre>
2244 typedef struct {
2245 int major;
2246 int minor;
2247 int micro;
2248 } XML_Expat_Version;
2249 </pre>
2251 Return the library version information as a structure.
2252 Some macros are also defined that support compile-time tests of the
2253 library version:
2254 <ul>
2258 </ul>
2259 Testing these constants is currently the best way to determine if
2260 particular parts of the Expat API are available.
2261 </div>
2264 const XML_Feature * XMLCALL
2265 XML_GetFeatureList();
2266 </pre>
2268 enum XML_FeatureEnum {
2269 XML_FEATURE_END = 0,
2270 XML_FEATURE_UNICODE,
2271 XML_FEATURE_UNICODE_WCHAR_T,
2272 XML_FEATURE_DTD,
2273 XML_FEATURE_CONTEXT_BYTES,
2274 XML_FEATURE_MIN_SIZE,
2275 XML_FEATURE_SIZEOF_XML_CHAR,
2276 XML_FEATURE_SIZEOF_XML_LCHAR,
2277 XML_FEATURE_NS,
2278 XML_FEATURE_LARGE_SIZE
2279 };
2281 typedef struct {
2282 enum XML_FeatureEnum feature;
2283 XML_LChar *name;
2284 long int value;
2285 } XML_Feature;
2286 </pre>
2289 Expat was configured at compile time. Most applications should not
2290 need to worry about this, but this information is otherwise not
2291 available from Expat. This function allows code that does need to
2292 check these features to do so at runtime.</p>
2297 identifying the feature-test macros Expat was compiled with. Since an
2298 application that requires this kind of information needs to determine
2304 all.</p>
2306 <p>Some features have an associated value. If there isn't an
2308 time, the following features have been defined to have values:</p>
2310 <dl>
2313 character.</dd>
2316 character.</dd>
2318 <dd>The maximum number of characters of context which can be
2321 </dl>
2322 </div>
2325 void XMLCALL
2326 XML_FreeContentModel(XML_Parser parser, XML_Content *model);
2327 </pre>
2332 This function should not be used for any other purpose.
2333 </div>
2335 <p>The following functions allow external code to share the memory
2337 is especially useful for third-party libraries that interact with a
2338 parser object created by application code, or heavily layered
2339 applications. This can be essential when using dynamically loaded
2340 libraries which use different C standard libraries (this can happen on
2341 Windows, at least).</p>
2344 void * XMLCALL
2345 XML_MemMalloc(XML_Parser parser, size_t size);
2346 </pre>
2350 pointer to the memory or NULL on failure. Memory allocated in this
2353 </div>
2356 void * XMLCALL
2357 XML_MemRealloc(XML_Parser parser, void *ptr, size_t size);
2358 </pre>
2366 a pointer to the memory or NULL on failure. On success, the original
2367 block has either been expanded or freed. On failure, the original
2368 block has not been freed; the caller is responsible for freeing the
2369 original block. Memory allocated in this way must be freed using
2372 </div>
2375 void XMLCALL
2376 XML_MemFree(XML_Parser parser, void *ptr);
2377 </pre>
2382 </div>
2384 <hr />
2388 </div>
2389 </body>
2390 </html>