diff options
Diffstat (limited to 'doc/library.html')
| -rw-r--r-- | doc/library.html | 137 |
1 files changed, 67 insertions, 70 deletions
diff --git a/doc/library.html b/doc/library.html index b5faade..afe4d77 100644 --- a/doc/library.html +++ b/doc/library.html @@ -7,27 +7,25 @@ H1 {font-family: Verdana,Arial,Helvetica} H2 {font-family: Verdana,Arial,Helvetica} H3 {font-family: Verdana,Arial,Helvetica} A:link, A:visited, A:active { text-decoration: underline } -</style><title>The parser interfaces</title></head><body bgcolor="#8b7765" text="#000000" link="#a06060" vlink="#000000"><table border="0" width="100%" cellpadding="5" cellspacing="0" align="center"><tr><td width="120"><a href="http://swpat.ffii.org/"><img src="epatents.png" alt="Action against software patents" /></a></td><td width="180"><a href="http://www.gnome.org/"><img src="gnome2.png" alt="Gnome2 Logo" /></a><a href="http://www.w3.org/Status"><img src="w3c.png" alt="W3C Logo" /></a><a href="http://www.redhat.com/"><img src="redhat.gif" alt="Red Hat Logo" /></a><div align="left"><a href="http://xmlsoft.org/"><img src="Libxml2-Logo-180x168.gif" alt="Made with Libxml2 Logo" /></a></div></td><td><table border="0" width="90%" cellpadding="2" cellspacing="0" align="center" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3" bgcolor="#fffacd"><tr><td align="center"><h1>The XML C parser and toolkit of Gnome</h1><h2>The parser interfaces</h2></td></tr></table></td></tr></table></td></tr></table><table border="0" cellpadding="4" cellspacing="0" width="100%" align="center"><tr><td bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td valign="top" width="200" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Developer Menu</b></center></td></tr><tr><td bgcolor="#fffacd"><form action="search.php" enctype="application/x-www-form-urlencoded" method="get"><input name="query" type="text" size="20" value="" /><input name="submit" type="submit" value="Search ..." /></form><ul><li><a href="index.html" style="font-weight:bold">Main Menu</a></li><li><a href="html/index.html" style="font-weight:bold">Reference Manual</a></li><li><a href="examples/index.html" style="font-weight:bold">Code Examples</a></li><li><a href="guidelines.html">XML Guidelines</a></li><li><a href="tutorial/index.html">Tutorial</a></li><li><a href="xmlreader.html">The Reader Interface</a></li><li><a href="ChangeLog.html">ChangeLog</a></li><li><a href="XSLT.html">XSLT</a></li><li><a href="python.html">Python and bindings</a></li><li><a href="architecture.html">libxml2 architecture</a></li><li><a href="tree.html">The tree output</a></li><li><a href="interface.html">The SAX interface</a></li><li><a href="xmlmem.html">Memory Management</a></li><li><a href="xmlio.html">I/O Interfaces</a></li><li><a href="library.html">The parser interfaces</a></li><li><a href="entities.html">Entities or no entities</a></li><li><a href="namespaces.html">Namespaces</a></li><li><a href="upgrade.html">Upgrading 1.x code</a></li><li><a href="threads.html">Thread safety</a></li><li><a href="DOM.html">DOM Principles</a></li><li><a href="example.html">A real example</a></li><li><a href="xml.html">flat page</a>, <a href="site.xsl">stylesheet</a></li></ul></td></tr></table><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>API Indexes</b></center></td></tr><tr><td bgcolor="#fffacd"><ul><li><a href="APIchunk0.html">Alphabetic</a></li><li><a href="APIconstructors.html">Constructors</a></li><li><a href="APIfunctions.html">Functions/Types</a></li><li><a href="APIfiles.html">Modules</a></li><li><a href="APIsymbols.html">Symbols</a></li></ul></td></tr></table><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Related links</b></center></td></tr><tr><td bgcolor="#fffacd"><ul><li><a href="http://mail.gnome.org/archives/xml/">Mail archive</a></li><li><a href="http://xmlsoft.org/XSLT/">XSLT libxslt</a></li><li><a href="http://phd.cs.unibo.it/gdome2/">DOM gdome2</a></li><li><a href="http://www.aleksey.com/xmlsec/">XML-DSig xmlsec</a></li><li><a href="ftp://xmlsoft.org/">FTP</a></li><li><a href="http://www.zlatkovic.com/projects/libxml/">Windows binaries</a></li><li><a href="http://www.blastwave.org/packages.php/libxml2">Solaris binaries</a></li><li><a href="http://www.explain.com.au/oss/libxml2xslt.html">MacOsX binaries</a></li><li><a href="http://libxmlplusplus.sourceforge.net/">C++ bindings</a></li><li><a href="http://www.zend.com/php5/articles/php5-xmlphp.php#Heading4">PHP bindings</a></li><li><a href="http://sourceforge.net/projects/libxml2-pas/">Pascal bindings</a></li><li><a href="http://libxml.rubyforge.org/">Ruby bindings</a></li><li><a href="http://tclxml.sourceforge.net/">Tcl bindings</a></li><li><a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Bug Tracker</a></li></ul></td></tr></table></td></tr></table></td><td valign="top" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%"><tr><td><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table border="0" cellpadding="3" cellspacing="1" width="100%"><tr><td bgcolor="#fffacd"><p>This section is directly intended to help programmers getting bootstrapped -using the XML tollkit from the C language. It is not intended to be -extensive. I hope the automatically generated documents will provide the -completeness required, but as a separate set of documents. The interfaces of -the XML parser are by principle low level, Those interested in a higher level -API should <a href="#DOM">look at DOM</a>.</p><p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are -separated from the <a href="html/libxml-htmlparser.html">HTML parser -interfaces</a>. Let's have a look at how the XML parser can be called:</p><h3><a name="Invoking" id="Invoking">Invoking the parser : the pull method</a></h3><p>Usually, the first thing to do is to read an XML input. The parser accepts -documents either from in-memory strings or from files. The functions are -defined in "parser.h":</p><dl><dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt> +</style><title>The parser interfaces</title></head><body bgcolor="#8b7765" text="#000000" link="#a06060" vlink="#000000"><table border="0" width="100%" cellpadding="5" cellspacing="0" align="center"><tr><td width="120"><a href="http://swpat.ffii.org/"><img src="epatents.png" alt="Action against software patents" /></a></td><td width="180"><a href="http://www.gnome.org/"><img src="gnome2.png" alt="Gnome2 Logo" /></a><a href="http://www.w3.org/Status"><img src="w3c.png" alt="W3C Logo" /></a><a href="http://www.redhat.com/"><img src="redhat.gif" alt="Red Hat Logo" /></a><div align="left"><a href="http://xmlsoft.org/"><img src="Libxml2-Logo-180x168.gif" alt="Made with Libxml2 Logo" /></a></div></td><td><table border="0" width="90%" cellpadding="2" cellspacing="0" align="center" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3" bgcolor="#fffacd"><tr><td align="center"><h1>The XML C parser and toolkit of Gnome</h1><h2>The parser interfaces</h2></td></tr></table></td></tr></table></td></tr></table><table border="0" cellpadding="4" cellspacing="0" width="100%" align="center"><tr><td bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td valign="top" width="200" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Developer Menu</b></center></td></tr><tr><td bgcolor="#fffacd"><form action="search.php" enctype="application/x-www-form-urlencoded" method="get"><input name="query" type="text" size="20" value="" /><input name="submit" type="submit" value="Search ..." /></form><ul><li><a href="index.html" style="font-weight:bold">Main Menu</a></li><li><a href="html/index.html" style="font-weight:bold">Reference Manual</a></li><li><a href="examples/index.html" style="font-weight:bold">Code Examples</a></li><li><a href="guidelines.html">XML Guidelines</a></li><li><a href="tutorial/index.html">Tutorial</a></li><li><a href="xmlreader.html">The Reader Interface</a></li><li><a href="ChangeLog.html">ChangeLog</a></li><li><a href="XSLT.html">XSLT</a></li><li><a href="python.html">Python and bindings</a></li><li><a href="architecture.html">libxml2 architecture</a></li><li><a href="tree.html">The tree output</a></li><li><a href="interface.html">The SAX interface</a></li><li><a href="xmlmem.html">Memory Management</a></li><li><a href="xmlio.html">I/O Interfaces</a></li><li><a href="library.html">The parser interfaces</a></li><li><a href="entities.html">Entities or no entities</a></li><li><a href="namespaces.html">Namespaces</a></li><li><a href="upgrade.html">Upgrading 1.x code</a></li><li><a href="threads.html">Thread safety</a></li><li><a href="DOM.html">DOM Principles</a></li><li><a href="example.html">A real example</a></li><li><a href="xml.html">flat page</a>, <a href="site.xsl">stylesheet</a></li></ul></td></tr></table><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>API Indexes</b></center></td></tr><tr><td bgcolor="#fffacd"><ul><li><a href="APIchunk0.html">Alphabetic</a></li><li><a href="APIconstructors.html">Constructors</a></li><li><a href="APIfunctions.html">Functions/Types</a></li><li><a href="APIfiles.html">Modules</a></li><li><a href="APIsymbols.html">Symbols</a></li></ul></td></tr></table><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Related links</b></center></td></tr><tr><td bgcolor="#fffacd"><ul><li><a href="http://mail.gnome.org/archives/xml/">Mail archive</a></li><li><a href="http://xmlsoft.org/XSLT/">XSLT libxslt</a></li><li><a href="http://phd.cs.unibo.it/gdome2/">DOM gdome2</a></li><li><a href="http://www.aleksey.com/xmlsec/">XML-DSig xmlsec</a></li><li><a href="ftp://xmlsoft.org/">FTP</a></li><li><a href="http://www.zlatkovic.com/projects/libxml/">Windows binaries</a></li><li><a href="http://www.blastwave.org/packages.php/libxml2">Solaris binaries</a></li><li><a href="http://www.explain.com.au/oss/libxml2xslt.html">MacOsX binaries</a></li><li><a href="http://libxmlplusplus.sourceforge.net/">C++ bindings</a></li><li><a href="http://www.zend.com/php5/articles/php5-xmlphp.php#Heading4">PHP bindings</a></li><li><a href="http://sourceforge.net/projects/libxml2-pas/">Pascal bindings</a></li><li><a href="http://libxml.rubyforge.org/">Ruby bindings</a></li><li><a href="http://tclxml.sourceforge.net/">Tcl bindings</a></li><li><a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Bug Tracker</a></li></ul></td></tr></table></td></tr></table></td><td valign="top" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%"><tr><td><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table border="0" cellpadding="3" cellspacing="1" width="100%"><tr><td bgcolor="#fffacd"><p>This section is directly intended to help programmers +gettingbootstrappedusing the XML tollkit from the C language. It is not +intended tobeextensive. I hope the automatically generated documents will +providethecompleteness required, but as a separate set of documents. The +interfacesofthe XML parser are by principle low level, Those interested in a +higherlevelAPI should <a href="#DOM">look at DOM</a>.</p><p>The <a href="html/libxml-parser.html">parser interfaces +forXML</a>areseparated from the <a href="html/libxml-htmlparser.html">HTMLparserinterfaces</a>. Let's have a +look at how the XML parser can becalled:</p><h3><a name="Invoking" id="Invoking">Invoking the parser : the pull method</a></h3><p>Usually, the first thing to do is to read an XML input. The +parseracceptsdocuments either from in-memory strings or from files. The +functionsaredefined in "parser.h":</p><dl><dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt> <dd><p>Parse a null-terminated string containing the document.</p> </dd> </dl><dl><dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt> - <dd><p>Parse an XML document contained in a (possibly compressed) - file.</p> + <dd><p>Parse an XML document contained in a (possibly compressed)file.</p> </dd> -</dl><p>The parser returns a pointer to the document structure (or NULL in case of -failure).</p><h3 id="Invoking1">Invoking the parser: the push method</h3><p>In order for the application to keep the control when the document is -being fetched (which is common for GUI based programs) libxml2 provides a -push interface, too, as of version 1.8.3. Here are the interface -functions:</p><pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax, +</dl><p>The parser returns a pointer to the document structure (or NULL in +caseoffailure).</p><h3 id="Invoking1">Invoking the parser: the push method</h3><p>In order for the application to keep the control when the document +isbeingfetched (which is common for GUI based programs) libxml2 provides +apushinterface, too, as of version 1.8.3. Here are the interfacefunctions:</p><pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax, void *user_data, const char *chunk, int size, @@ -54,17 +52,17 @@ int xmlParseChunk (xmlParserCtxtPtr ctxt, doc = ctxt->myDoc; xmlFreeParserCtxt(ctxt); } - }</pre><p>The HTML parser embedded into libxml2 also has a push interface; the -functions are just prefixed by "html" rather than "xml".</p><h3 id="Invoking2">Invoking the parser: the SAX interface</h3><p>The tree-building interface makes the parser memory-hungry, first loading -the document in memory and then building the tree itself. Reading a document -without building the tree is possible using the SAX interfaces (see SAX.h and -<a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James -Henstridge's documentation</a>). Note also that the push interface can be -limited to SAX: just use the two first arguments of -<code>xmlCreatePushParserCtxt()</code>.</p><h3><a name="Building" id="Building">Building a tree from scratch</a></h3><p>The other way to get an XML tree in memory is by building it. Basically -there is a set of functions dedicated to building new elements. (These are -also described in <libxml/tree.h>.) For example, here is a piece of -code that produces the XML document used in the previous examples:</p><pre> #include <libxml/tree.h> + }</pre><p>The HTML parser embedded into libxml2 also has a push +interface;thefunctions are just prefixed by "html" rather than "xml".</p><h3 id="Invoking2">Invoking the parser: the SAX interface</h3><p>The tree-building interface makes the parser memory-hungry, +firstloadingthe document in memory and then building the tree itself. Reading +adocumentwithout building the tree is possible using the SAX interfaces +(seeSAX.h and<a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">JamesHenstridge'sdocumentation</a>). +Note also that the push interface can belimited to SAX:just use the two first +arguments of<code>xmlCreatePushParserCtxt()</code>.</p><h3><a name="Building" id="Building">Building a tree from scratch</a></h3><p>The other way to get an XML tree in memory is by building +it.Basicallythere is a set of functions dedicated to building new +elements.(These arealso described in <libxml/tree.h>.) For example, +here is apiece ofcode that produces the XML document used in the previous +examples:</p><pre> #include <libxml/tree.h> xmlDocPtr doc; xmlNodePtr tree, subtree; @@ -78,59 +76,58 @@ code that produces the XML document used in the previous examples:</p><pre> # subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure"); subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ..."); subtree = xmlNewChild(tree, NULL, "image", NULL); - xmlSetProp(subtree, "href", "linus.gif");</pre><p>Not really rocket science ...</p><h3><a name="Traversing" id="Traversing">Traversing the tree</a></h3><p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your -code has access to the internal structure of all the elements of the tree. -The names should be somewhat simple like <strong>parent</strong>, -<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>, -<strong>properties</strong>, etc... For example, still with the previous -example:</p><pre><code>doc->children->children->children</code></pre><p>points to the title element,</p><pre>doc->children->children->next->children->children</pre><p>points to the text node containing the chapter title "The Linux -adventure".</p><p><strong>NOTE</strong>: XML allows <em>PI</em>s and <em>comments</em> to be -present before the document root, so <code>doc->children</code> may point -to an element which is not the document Root Element; a function -<code>xmlDocGetRootElement()</code> was added for this purpose.</p><h3><a name="Modifying" id="Modifying">Modifying the tree</a></h3><p>Functions are provided for reading and writing the document content. Here -is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p><dl><dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const - xmlChar *value);</code></dt> - <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. - The value can be NULL.</p> + xmlSetProp(subtree, "href", "linus.gif");</pre><p>Not really rocket science ...</p><h3><a name="Traversing" id="Traversing">Traversing the tree</a></h3><p>Basically by <a href="html/libxml-tree.html">including"tree.h"</a>yourcode +has access to the internal structure of all the elementsof the tree.The names +should be somewhat simple +like<strong>parent</strong>,<strong>children</strong>, +<strong>next</strong>,<strong>prev</strong>,<strong>properties</strong>, +etc... For example, stillwith the previousexample:</p><pre><code>doc->children->children->children</code></pre><p>points to the title element,</p><pre>doc->children->children->next->children->children</pre><p>points to the text node containing the chapter title +"TheLinuxadventure".</p><p><strong>NOTE</strong>: XML allows <em>PI</em>s and +<em>comments</em>tobepresent before the document root, so +<code>doc->children</code>maypointto an element which is not the document +Root Element; afunction<code>xmlDocGetRootElement()</code>was added for this +purpose.</p><h3><a name="Modifying" id="Modifying">Modifying the tree</a></h3><p>Functions are provided for reading and writing the document content.Hereis +an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p><dl><dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar + *name,constxmlChar *value);</code></dt> + <dd><p>This sets (or changes) an attribute carried by an ELEMENT + node.Thevalue can be NULL.</p> </dd> -</dl><dl><dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar - *name);</code></dt> - <dd><p>This function returns a pointer to new copy of the property - content. Note that the user must deallocate the result.</p> +</dl><dl><dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, + constxmlChar*name);</code></dt> + <dd><p>This function returns a pointer to new copy of thepropertycontent. + Note that the user must deallocate the result.</p> </dd> -</dl><p>Two functions are provided for reading and writing the text associated -with elements:</p><dl><dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar - *value);</code></dt> - <dd><p>This function takes an "external" string and converts it to one - text node or possibly to a list of entity and text nodes. All - non-predefined entity references like &Gnome; will be stored - internally as entity nodes, hence the result of the function may not be - a single node.</p> +</dl><p>Two functions are provided for reading and writing the text +associatedwithelements:</p><dl><dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, + constxmlChar*value);</code></dt> + <dd><p>This function takes an "external" string and converts it toonetext + node or possibly to a list of entity and text nodes.Allnon-predefined + entity references like &Gnome; will bestoredinternally as entity + nodes, hence the result of the function maynot bea single node.</p> </dd> -</dl><dl><dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int - inLine);</code></dt> - <dd><p>This function is the inverse of - <code>xmlStringGetNodeList()</code>. It generates a new string - containing the content of the text and entity nodes. Note the extra - argument inLine. If this argument is set to 1, the function will expand - entity references. For example, instead of returning the &Gnome; - XML encoding in the string, it will substitute it with its value (say, - "GNU Network Object Model Environment").</p> +</dl><dl><dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr + list,intinLine);</code></dt> + <dd><p>This function is the inverseof<code>xmlStringGetNodeList()</code>. + It generates a newstringcontaining the content of the text and entity + nodes. Note theextraargument inLine. If this argument is set to 1, the + function willexpandentity references. For example, instead of + returning the&Gnome;XML encoding in the string, it will substitute + it with itsvalue (say,"GNU Network Object Model Environment").</p> </dd> -</dl><h3><a name="Saving" id="Saving">Saving a tree</a></h3><p>Basically 3 options are possible:</p><dl><dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int - *size);</code></dt> +</dl><h3><a name="Saving" id="Saving">Saving a tree</a></h3><p>Basically 3 options are possible:</p><dl><dt><code>void xmlDocDumpMemory(xmlDocPtr cur, + xmlChar**mem,int*size);</code></dt> <dd><p>Returns a buffer into which the document has been saved.</p> </dd> </dl><dl><dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt> <dd><p>Dumps a document to an open file descriptor.</p> </dd> </dl><dl><dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt> - <dd><p>Saves the document to a file. In this case, the compression - interface is triggered if it has been turned on.</p> + <dd><p>Saves the document to a file. In this case, + thecompressioninterface is triggered if it has been turned on.</p> </dd> -</dl><h3><a name="Compressio" id="Compressio">Compression</a></h3><p>The library transparently handles compression when doing file-based -accesses. The level of compression on saves can be turned on either globally -or individually for one file:</p><dl><dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt> +</dl><h3><a name="Compressio" id="Compressio">Compression</a></h3><p>The library transparently handles compression when +doingfile-basedaccesses. The level of compression on saves can be turned on +eithergloballyor individually for one file:</p><dl><dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt> <dd><p>Gets the document compression ratio (0-9).</p> </dd> </dl><dl><dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt> |