apa.html apb.html apc.html apd.html ar01s02.html ar01s03.html ar01s04.html
Tue Jun 4 09:09:18 MDT 2002 John Fleck <jfleck@inkstain.net>
* added doc/tutorial, including:
apa.html
apb.html
apc.html
apd.html
ar01s02.html
ar01s03.html
ar01s04.html
ar01s05.html
ar01s06.html
includeaddattribute.c
includeaddkeyword.c
includekeyword.c
includestory.xml
index.html
xmltutorial.xml
libxml tutorial, including generated html
diff --git a/ChangeLog b/ChangeLog
index 6c2d490..553e2ea 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,23 @@
+Tue Jun 4 09:09:18 MDT 2002 John Fleck <jfleck@inkstain.net>
+
+ * added doc/tutorial, including:
+ apa.html
+ apb.html
+ apc.html
+ apd.html
+ ar01s02.html
+ ar01s03.html
+ ar01s04.html
+ ar01s05.html
+ ar01s06.html
+ includeaddattribute.c
+ includeaddkeyword.c
+ includekeyword.c
+ includestory.xml
+ index.html
+ xmltutorial.xml
+ libxml tutorial, including generated html
+
Mon Jun 3 21:21:26 2002 Aleksey Sanin <aleksey@aleksey.com>
* result/c14n/exc-without-comments/merlin-c14n-two-*
diff --git a/doc/tutorial/apa.html b/doc/tutorial/apa.html
new file mode 100644
index 0000000..d01ea2e
--- /dev/null
+++ b/doc/tutorial/apa.html
@@ -0,0 +1,15 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>A. Sample Document</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="ar01s06.html" title="Writing Attribute"><link rel="next" href="apb.html" title="B. Code for Keyword Example"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">A. Sample Document</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ar01s06.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="apb.html">Next</a></td></tr></table><hr></div><div class="appendix"><h2 class="title" style="clear: both"><a name="sampledoc"></a>A. Sample Document</h2><pre class="programlisting">
+<?xml version="1.0"?>
+<story>
+ <storyinfo>
+ <author>John Fleck</author>
+ <datewritten>June 2, 2002</datewritten>
+ <keyword>example keyword</keyword>
+ </storyinfo>
+ <body>
+ <headline>This is the headline</headline>
+ <para>This is the body text.</para>
+ </body>
+</story>
+</pre></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ar01s06.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="apb.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Writing Attribute </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> B. Code for Keyword Example</td></tr></table></div></body></html>
diff --git a/doc/tutorial/apb.html b/doc/tutorial/apb.html
new file mode 100644
index 0000000..e3b119f
--- /dev/null
+++ b/doc/tutorial/apb.html
@@ -0,0 +1,78 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>B. Code for Keyword Example</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="apa.html" title="A. Sample Document"><link rel="next" href="apc.html" title="C. Code for Add Keyword Example"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">B. Code for Keyword Example</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="apa.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="apc.html">Next</a></td></tr></table><hr></div><div class="appendix"><h2 class="title" style="clear: both"><a name="keywordappendix"></a>B. Code for Keyword Example</h2><p>
+ <pre class="programlisting">
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/parser.h>
+
+void
+parseStory (xmlDocPtr doc, xmlNodePtr cur) {
+
+ cur = cur->xmlChildrenNode;
+ while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"keyword"))) {
+ printf("keyword: %s\n", xmlNodeListGetString(doc, cur->xmlChildrenNode, 1));
+ }
+ cur = cur->next;
+ }
+ return;
+}
+
+static void
+parseDoc(char *docname) {
+
+ xmlDocPtr doc;
+ xmlNodePtr cur;
+
+ doc = xmlParseFile(docname);
+
+ if (doc == NULL ) {
+ fprintf(stderr,"Document not parsed successfully. \n");
+ return;
+ }
+
+ cur = xmlDocGetRootElement(doc);
+
+ if (cur == NULL) {
+ fprintf(stderr,"empty document\n");
+ xmlFreeDoc(doc);
+ return;
+ }
+
+ if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
+ fprintf(stderr,"document of the wrong type, root node != story");
+ xmlFreeDoc(doc);
+ return;
+ }
+
+ cur = cur->xmlChildrenNode;
+ while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"storyinfo"))){
+ parseStory (doc, cur);
+ }
+
+ cur = cur->next;
+ }
+
+}
+
+int
+main(int argc, char **argv) {
+
+ char *docname;
+
+ if (argc <= 1) {
+ printf("Usage: %s docname\n", argv[0]);
+ return(0);
+ }
+
+ docname = argv[1];
+ parseDoc (docname);
+
+ return (1);
+}
+
+</pre>
+ </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="apa.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="apc.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">A. Sample Document </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> C. Code for Add Keyword Example</td></tr></table></div></body></html>
diff --git a/doc/tutorial/apc.html b/doc/tutorial/apc.html
new file mode 100644
index 0000000..62ca6b2
--- /dev/null
+++ b/doc/tutorial/apc.html
@@ -0,0 +1,77 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>C. Code for Add Keyword Example</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="apb.html" title="B. Code for Keyword Example"><link rel="next" href="apd.html" title="D. Code for Add Attribute Example"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">C. Code for Add Keyword Example</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="apb.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="apd.html">Next</a></td></tr></table><hr></div><div class="appendix"><h2 class="title" style="clear: both"><a name="addkeywordappendix"></a>C. Code for Add Keyword Example</h2><p>
+ <pre class="programlisting">
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/parser.h>
+
+void
+parseStory (xmlDocPtr doc, xmlNodePtr cur, char *keyword) {
+
+ xmlNewTextChild (cur, NULL, "keyword", keyword);
+ return;
+}
+
+xmlDocPtr
+parseDoc(char *docname, char *keyword) {
+
+ xmlDocPtr doc;
+ xmlNodePtr cur;
+
+ doc = xmlParseFile(docname);
+
+ if (doc == NULL ) {
+ fprintf(stderr,"Document not parsed successfully. \n");
+ return (NULL);
+ }
+
+ cur = xmlDocGetRootElement(doc);
+
+ if (cur == NULL) {
+ fprintf(stderr,"empty document\n");
+ xmlFreeDoc(doc);
+ return (NULL);
+ }
+
+ if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
+ fprintf(stderr,"document of the wrong type, root node != story");
+ xmlFreeDoc(doc);
+ return (NULL);
+ }
+
+ cur = cur->xmlChildrenNode;
+ while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"storyinfo"))){
+ parseStory (doc, cur, keyword);
+ }
+
+ cur = cur->next;
+ }
+ return(doc);
+}
+
+int
+main(int argc, char **argv) {
+
+ char *docname;
+ char *keyword;
+ xmlDocPtr doc;
+
+ if (argc <= 2) {
+ printf("Usage: %s docname, keyword\n", argv[0]);
+ return(0);
+ }
+
+ docname = argv[1];
+ keyword = argv[2];
+ doc = parseDoc (docname, keyword);
+ if (doc != NULL) {
+ xmlSaveFormatFile (docname, doc, 0);
+ }
+ return (1);
+}
+
+</pre>
+ </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="apb.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="apd.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">B. Code for Keyword Example </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> D. Code for Add Attribute Example</td></tr></table></div></body></html>
diff --git a/doc/tutorial/apd.html b/doc/tutorial/apd.html
new file mode 100644
index 0000000..66cddfe
--- /dev/null
+++ b/doc/tutorial/apd.html
@@ -0,0 +1,67 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>D. Code for Add Attribute Example</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="apc.html" title="C. Code for Add Keyword Example"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">D. Code for Add Attribute Example</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="apc.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> </td></tr></table><hr></div><div class="appendix"><h2 class="title" style="clear: both"><a name="addattributeappendix"></a>D. Code for Add Attribute Example</h2><p>
+ <pre class="programlisting">
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/parser.h>
+
+
+xmlDocPtr
+parseDoc(char *docname, char *uri) {
+
+ xmlDocPtr doc;
+ xmlNodePtr cur;
+ xmlNodePtr newnode;
+ xmlAttrPtr newattr;
+
+ doc = xmlParseFile(docname);
+
+ if (doc == NULL ) {
+ fprintf(stderr,"Document not parsed successfully. \n");
+ return (NULL);
+ }
+
+ cur = xmlDocGetRootElement(doc);
+
+ if (cur == NULL) {
+ fprintf(stderr,"empty document\n");
+ xmlFreeDoc(doc);
+ return (NULL);
+ }
+
+ if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
+ fprintf(stderr,"document of the wrong type, root node != story");
+ xmlFreeDoc(doc);
+ return (NULL);
+ }
+
+ newnode = xmlNewTextChild (cur, NULL, "reference", NULL);
+ newattr = xmlNewProp (newnode, "uri", uri);
+ return(doc);
+}
+
+int
+main(int argc, char **argv) {
+
+ char *docname;
+ char *uri;
+ xmlDocPtr doc;
+
+ if (argc <= 2) {
+ printf("Usage: %s docname, uri\n", argv[0]);
+ return(0);
+ }
+
+ docname = argv[1];
+ uri = argv[2];
+ doc = parseDoc (docname, uri);
+ if (doc != NULL) {
+ xmlSaveFormatFile (docname, doc, 1);
+ }
+ return (1);
+}
+
+</pre>
+ </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="apc.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> </td></tr><tr><td width="40%" align="left" valign="top">C. Code for Add Keyword Example </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> </td></tr></table></div></body></html>
diff --git a/doc/tutorial/ar01s02.html b/doc/tutorial/ar01s02.html
new file mode 100644
index 0000000..ba39021
--- /dev/null
+++ b/doc/tutorial/ar01s02.html
@@ -0,0 +1,11 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>Data Types</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="index.html" title="Libxml Tutorial"><link rel="next" href="ar01s03.html" title="Parsing the file"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Data Types</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="index.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="ar01s03.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="xmltutorialdatatypes"></a>Data Types</h2></div></div><p>Libxml declares a number of datatypes we
+ will encounter repeatedly, hiding the messy stuff so you do not have to deal
+ with it unless you have some specific need.</p><p>
+ <div class="variablelist"><dl><dt><span class="term"><a href="http://xmlsoft.org/html/libxml-tree.html#XMLCHAR" target="_top">xmlChar</a></span></dt><dd><p>A basic replacement for char, a byte in a UTF-8 encoded
+ string.</p></dd><dt><span class="term">
+ <a href="http://xmlsoft.org/html/libxml-tree.html#XMLDOC" target="_top">xmlDoc</a></span></dt><dd><p>A structure containing the tree created by a parsed doc. <a href="http://xmlsoft.org/html/libxml-tree.html#XMLDOCPTR" target="_top">xmlDocPtr</a>
+ is a pointer to the structure.</p></dd><dt><span class="term"><a href="http://xmlsoft.org/html/libxml-tree.html#XMLNODEPTR" target="_top">xmlNodePtr</a>
+ and <a href="http://xmlsoft.org/html/libxml-tree.html#XMLNODE" target="_top">xmlNode</a></span></dt><dd><p>A structure containing a single node. <a href="http://xmlsoft.org/html/libxml-tree.html#XMLNODEPTR" target="_top">xmlNodePtr</a>
+ is a pointer to the structure, and is used in traversing the document tree.</p></dd></dl></div>
+ </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="index.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ar01s03.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Libxml Tutorial </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Parsing the file</td></tr></table></div></body></html>
diff --git a/doc/tutorial/ar01s03.html b/doc/tutorial/ar01s03.html
new file mode 100644
index 0000000..62429fa
--- /dev/null
+++ b/doc/tutorial/ar01s03.html
@@ -0,0 +1,33 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>Parsing the file</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="ar01s02.html" title="Data Types"><link rel="next" href="ar01s04.html" title="Retrieving Element Content"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Parsing the file</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ar01s02.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="ar01s04.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="xmltutorialparsing"></a>Parsing the file</h2></div></div><p>Parsing the file requires only the name of the file and a single
+ function call, plus error checking. Full code: <a href="apb.html" title="B. Code for Keyword Example">Appendix B</a></p><p>
+ <pre class="programlisting">
+ <a name="declaredoc"></a><img src="images/callouts/1.png" alt="1" border="0"> xmlDocPtr doc;
+ <a name="declarenode"></a><img src="images/callouts/2.png" alt="2" border="0"> xmlNodePtr cur;
+
+ <a name="parsefile"></a><img src="images/callouts/3.png" alt="3" border="0"> doc = xmlParseFile(docname);
+
+ <a name="checkparseerror"></a><img src="images/callouts/4.png" alt="4" border="0"> if (doc == NULL ) {
+ fprintf(stderr,"Document not parsed successfully. \n");
+ return;
+ }
+
+ <a name="getrootelement"></a><img src="images/callouts/5.png" alt="5" border="0"> cur = xmlDocGetRootElement(doc);
+
+ <a name="checkemptyerror"></a><img src="images/callouts/6.png" alt="6" border="0"> if (cur == NULL) {
+ fprintf(stderr,"empty document\n");
+ xmlFreeDoc(doc);
+ return;
+ }
+
+ <a name="checkroottype"></a><img src="images/callouts/7.png" alt="7" border="0"> if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
+ fprintf(stderr,"document of the wrong type, root node != story");
+ xmlFreeDoc(doc);
+ return;
+ }
+
+ </pre>
+ <div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><a href="#declaredoc"><img src="images/callouts/1.png" alt="1" border="0"></a> </td><td valign="top" align="left"><p>Declare the pointer that will point to your parsed document.</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#declarenode"><img src="images/callouts/2.png" alt="2" border="0"></a> </td><td valign="top" align="left"><p>Declare a node pointer (you'll need this in order to
+ interact with individual nodes).</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#checkparseerror"><img src="images/callouts/4.png" alt="4" border="0"></a> </td><td valign="top" align="left"><p>Check to see that the document was successfully parsed.</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#getrootelement"><img src="images/callouts/5.png" alt="5" border="0"></a> </td><td valign="top" align="left"><p>Retrieve the document's root element.</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#checkemptyerror"><img src="images/callouts/6.png" alt="6" border="0"></a> </td><td valign="top" align="left"><p>Check to make sure the document actually contains something.</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#checkroottype"><img src="images/callouts/7.png" alt="7" border="0"></a> </td><td valign="top" align="left"><p>In our case, we need to make sure the document is the right
+ type. "story" is the root type of my documents.</p></td></tr></table></div>
+ </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ar01s02.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ar01s04.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Data Types </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Retrieving Element Content</td></tr></table></div></body></html>
diff --git a/doc/tutorial/ar01s04.html b/doc/tutorial/ar01s04.html
new file mode 100644
index 0000000..8a9867d
--- /dev/null
+++ b/doc/tutorial/ar01s04.html
@@ -0,0 +1,50 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>Retrieving Element Content</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="ar01s03.html" title="Parsing the file"><link rel="next" href="ar01s05.html" title="Writing element content"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Retrieving Element Content</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ar01s03.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="ar01s05.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="xmltutorialgettext"></a>Retrieving Element Content</h2></div></div><p>Retrieving the content of an element involves traversing the document
+ tree until you find what you are looking for. In this case, we are looking
+ for an element called "keyword" contained within element called "story". The
+ process to find the node we are interested in involves tediously walking the
+ tree. We assume you already have an xmlDocPtr called <tt>doc</tt>
+ and an xmlNodPtr called <tt>cur</tt>.</p><p>
+ <pre class="programlisting">
+ <a name="getchildnode"></a><img src="images/callouts/1.png" alt="1" border="0"> cur = cur->xmlChildrenNode;
+ <a name="huntstoryinfo"></a><img src="images/callouts/2.png" alt="2" border="0"> while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"storyinfo"))){
+ parseStory (doc, cur);
+ }
+
+ cur = cur->next;
+ }
+
+ </pre>
+
+ <div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><a href="#getchildnode"><img src="images/callouts/1.png" alt="1" border="0"></a> </td><td valign="top" align="left"><p>Get the first child node of <tt>cur</tt>. At this
+ point, <tt>cur</tt> points at the document root, which is
+ the element "story".</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#huntstoryinfo"><img src="images/callouts/2.png" alt="2" border="0"></a> </td><td valign="top" align="left"><p>This loop iterates through the elements that are children of
+ "story", looking for one called "storyinfo". That
+ is the element that will contain the "keywords" we are
+ looking for. It uses the libxml string
+ comparison
+ function, <tt><a href="http://xmlsoft.org/html/libxml-parser.html#XMLSTRCMP" target="_top">xmlStrcmp</a></tt>. If there is a match, it calls the function <tt>parseStory</tt>.</p></td></tr></table></div>
+ </p><p>
+ <pre class="programlisting">
+void
+parseStory (xmlDocPtr doc, xmlNodePtr cur) {
+
+ <a name="anothergetchild"></a><img src="images/callouts/1.png" alt="1" border="0"> cur = cur->xmlChildrenNode;
+ <a name="findkeyword"></a><img src="images/callouts/2.png" alt="2" border="0"> while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"keyword"))) {
+ <a name="foundkeyword"></a><img src="images/callouts/3.png" alt="3" border="0"> printf("keyword: %s\n", xmlNodeListGetString(doc, cur->xmlChildrenNode, 1));
+ }
+ cur = cur->next;
+ }
+ return;
+}
+ </pre>
+ <div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><a href="#anothergetchild"><img src="images/callouts/1.png" alt="1" border="0"></a> </td><td valign="top" align="left"><p>Again we get the first child node.</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#findkeyword"><img src="images/callouts/2.png" alt="2" border="0"></a> </td><td valign="top" align="left"><p>Like the loop above, we then iterate through the nodes, looking
+ for one that matches the element we're interested in, in this case
+ "keyword".</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#foundkeyword"><img src="images/callouts/3.png" alt="3" border="0"></a> </td><td valign="top" align="left"><p>When we find the "keyword" element, we need to print
+ its contents. Remember that in XML, the text
+ contained within an element is a child node of that element, so we
+ turn to <tt>cur->xmlChildrenNode</tt>. To retrieve it, we
+ use the function <tt><a href="http://xmlsoft.org/html/libxml-tree.html#XMLNODELISTGETSTRING" target="_top">xmlNodeListGetString</a></tt>, which also takes the <tt>doc</tt> pointer as an argument. In this case, we just print it out.</p></td></tr></table></div>
+ </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ar01s03.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ar01s05.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Parsing the file </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Writing element content</td></tr></table></div></body></html>
diff --git a/doc/tutorial/ar01s05.html b/doc/tutorial/ar01s05.html
new file mode 100644
index 0000000..5f90af8
--- /dev/null
+++ b/doc/tutorial/ar01s05.html
@@ -0,0 +1,34 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>Writing element content</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="ar01s04.html" title="Retrieving Element Content"><link rel="next" href="ar01s06.html" title="Writing Attribute"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Writing element content</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ar01s04.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="ar01s06.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="xmltutorialwritingcontent"></a>Writing element content</h2></div></div><p>Writing element content uses many of the same steps we used above
+ — parsing the document and walking the tree. We parse the document,
+ then traverse the tree to find the place we want to insert our element. For
+ this example, we want to again find the "storyinfo" element and
+ this time insert a keyword. Then we'll write the file to disk. Full code:
+ <a href="apc.html" title="C. Code for Add Keyword Example">Appendix C</a></p><p>
+ The main difference in this example is in
+ <tt>parseStory</tt>:
+
+ <pre class="programlisting">
+void
+parseStory (xmlDocPtr doc, xmlNodePtr cur, char *keyword) {
+
+ <a name="addkeyword"></a><img src="images/callouts/1.png" alt="1" border="0"> xmlNewTextChild (cur, NULL, "keyword", keyword);
+ return;
+}
+ </pre>
+ <div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><a href="#addkeyword"><img src="images/callouts/1.png" alt="1" border="0"></a> </td><td valign="top" align="left"><p>The <tt><a href="http://xmlsoft.org/html/libxml-tree.html#XMLNEWTEXTCHILD" target="_top">xmlNewTextChild</a></tt>
+ function adds a new child element at the
+ current node pointer's location in the
+ tree, specificied by <tt>cur</tt>.</p></td></tr></table></div>
+ </p><p>
+ Once the node has been added, we would like to write the document to
+ file. Is you want the element to have a namespace, you can add it here as
+ well. In our case, the namespace is NULL.
+ <pre class="programlisting">
+ xmlSaveFormatFile (docname, doc, 1);
+ </pre>
+ The first parameter is the name of the file to be written. You'll notice
+ it is the same as the file we just read. In this case, we just write over
+ the old file. The second parameter is a pointer to the xmlDoc
+ structure. Setting the third parameter equal to one ensures indenting on output.
+ </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ar01s04.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ar01s06.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Retrieving Element Content </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Writing Attribute</td></tr></table></div></body></html>
diff --git a/doc/tutorial/ar01s06.html b/doc/tutorial/ar01s06.html
new file mode 100644
index 0000000..8d2afd1
--- /dev/null
+++ b/doc/tutorial/ar01s06.html
@@ -0,0 +1,30 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>Writing Attribute</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="ar01s05.html" title="Writing element content"><link rel="next" href="apa.html" title="A. Sample Document"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Writing Attribute</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ar01s05.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="apa.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="xmltutorialwritingattribute"></a>Writing Attribute</h2></div></div><p>Writing an attribute is similar to writing text to a new element. In
+ this case, we'll add a reference URI to our
+ document. Full code:<a href="apd.html" title="D. Code for Add Attribute Example">Appendix D</a>.</p><p>
+ A <tt class="sgmltag-element">reference</tt> is a child of the <tt class="sgmltag-element">story</tt>
+ element, so finding the place to put our new element and attribute is
+ simple. As soon as we do the error-checking test in our
+ <tt>parseDoc</tt>, we are in the right spot to add our
+ element. But before we do that, we need to make a declaration using a
+ datatype we have not seen yet:
+ <pre class="programlisting">
+ xmlAttrPtr newattr;
+ </pre>
+ We also need an extra xmlNodePtr:
+ <pre class="programlisting">
+ xmlNodePtr newnode;
+ </pre>
+ </p><p>
+ The rest of <tt>parseDoc</tt> is the same as before until we
+ check to see if our root element is <tt class="sgmltag-element">story</tt>. If it is,
+ then we know we are at the right spot to add our element:
+
+ <pre class="programlisting">
+ <a name="addreferencenode"></a><img src="images/callouts/1.png" alt="1" border="0"> newnode = xmlNewTextChild (cur, NULL, "reference", NULL);
+ <a name="addattributenode"></a><img src="images/callouts/2.png" alt="2" border="0"> newattr = xmlNewProp (newnode, "uri", uri);
+ </pre>
+ <div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><a href="#addreferencenode"><img src="images/callouts/1.png" alt="1" border="0"></a> </td><td valign="top" align="left"><p>First we add a new node at the location of the current node
+ pointer, <tt>cur.</tt> using the <a href="http://xmlsoft.org/html/libxml-tree.html#XMLNEWTEXTCHILD" target="_top">xmlNewTextChild</a> function.</p></td></tr></table></div>
+ </p><p>Once the node is added, the file is written to disk just as in the
+ previous example in which we added an element with text content.</p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ar01s05.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="apa.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Writing element content </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> A. Sample Document</td></tr></table></div></body></html>
diff --git a/doc/tutorial/includeaddattribute.c b/doc/tutorial/includeaddattribute.c
new file mode 100644
index 0000000..45321b3
--- /dev/null
+++ b/doc/tutorial/includeaddattribute.c
@@ -0,0 +1,63 @@
+<![CDATA[
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/parser.h>
+
+
+xmlDocPtr
+parseDoc(char *docname, char *uri) {
+
+ xmlDocPtr doc;
+ xmlNodePtr cur;
+ xmlNodePtr newnode;
+ xmlAttrPtr newattr;
+
+ doc = xmlParseFile(docname);
+
+ if (doc == NULL ) {
+ fprintf(stderr,"Document not parsed successfully. \n");
+ return (NULL);
+ }
+
+ cur = xmlDocGetRootElement(doc);
+
+ if (cur == NULL) {
+ fprintf(stderr,"empty document\n");
+ xmlFreeDoc(doc);
+ return (NULL);
+ }
+
+ if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
+ fprintf(stderr,"document of the wrong type, root node != story");
+ xmlFreeDoc(doc);
+ return (NULL);
+ }
+
+ newnode = xmlNewTextChild (cur, NULL, "reference", NULL);
+ newattr = xmlNewProp (newnode, "uri", uri);
+ return(doc);
+}
+
+int
+main(int argc, char **argv) {
+
+ char *docname;
+ char *uri;
+ xmlDocPtr doc;
+
+ if (argc <= 2) {
+ printf("Usage: %s docname, uri\n", argv[0]);
+ return(0);
+ }
+
+ docname = argv[1];
+ uri = argv[2];
+ doc = parseDoc (docname, uri);
+ if (doc != NULL) {
+ xmlSaveFormatFile (docname, doc, 1);
+ }
+ return (1);
+}
+]]>
diff --git a/doc/tutorial/includeaddkeyword.c b/doc/tutorial/includeaddkeyword.c
new file mode 100644
index 0000000..8f5de90
--- /dev/null
+++ b/doc/tutorial/includeaddkeyword.c
@@ -0,0 +1,73 @@
+<![CDATA[
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/parser.h>
+
+void
+parseStory (xmlDocPtr doc, xmlNodePtr cur, char *keyword) {
+
+ xmlNewTextChild (cur, NULL, "keyword", keyword);
+ return;
+}
+
+xmlDocPtr
+parseDoc(char *docname, char *keyword) {
+
+ xmlDocPtr doc;
+ xmlNodePtr cur;
+
+ doc = xmlParseFile(docname);
+
+ if (doc == NULL ) {
+ fprintf(stderr,"Document not parsed successfully. \n");
+ return (NULL);
+ }
+
+ cur = xmlDocGetRootElement(doc);
+
+ if (cur == NULL) {
+ fprintf(stderr,"empty document\n");
+ xmlFreeDoc(doc);
+ return (NULL);
+ }
+
+ if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
+ fprintf(stderr,"document of the wrong type, root node != story");
+ xmlFreeDoc(doc);
+ return (NULL);
+ }
+
+ cur = cur->xmlChildrenNode;
+ while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"storyinfo"))){
+ parseStory (doc, cur, keyword);
+ }
+
+ cur = cur->next;
+ }
+ return(doc);
+}
+
+int
+main(int argc, char **argv) {
+
+ char *docname;
+ char *keyword;
+ xmlDocPtr doc;
+
+ if (argc <= 2) {
+ printf("Usage: %s docname, keyword\n", argv[0]);
+ return(0);
+ }
+
+ docname = argv[1];
+ keyword = argv[2];
+ doc = parseDoc (docname, keyword);
+ if (doc != NULL) {
+ xmlSaveFormatFile (docname, doc, 0);
+ }
+ return (1);
+}
+]]>
diff --git a/doc/tutorial/includekeyword.c b/doc/tutorial/includekeyword.c
new file mode 100644
index 0000000..af2627d
--- /dev/null
+++ b/doc/tutorial/includekeyword.c
@@ -0,0 +1,74 @@
+<![CDATA[
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/parser.h>
+
+void
+parseStory (xmlDocPtr doc, xmlNodePtr cur) {
+
+ cur = cur->xmlChildrenNode;
+ while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"keyword"))) {
+ printf("keyword: %s\n", xmlNodeListGetString(doc, cur->xmlChildrenNode, 1));
+ }
+ cur = cur->next;
+ }
+ return;
+}
+
+static void
+parseDoc(char *docname) {
+
+ xmlDocPtr doc;
+ xmlNodePtr cur;
+
+ doc = xmlParseFile(docname);
+
+ if (doc == NULL ) {
+ fprintf(stderr,"Document not parsed successfully. \n");
+ return;
+ }
+
+ cur = xmlDocGetRootElement(doc);
+
+ if (cur == NULL) {
+ fprintf(stderr,"empty document\n");
+ xmlFreeDoc(doc);
+ return;
+ }
+
+ if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
+ fprintf(stderr,"document of the wrong type, root node != story");
+ xmlFreeDoc(doc);
+ return;
+ }
+
+ cur = cur->xmlChildrenNode;
+ while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"storyinfo"))){
+ parseStory (doc, cur);
+ }
+
+ cur = cur->next;
+ }
+
+}
+
+int
+main(int argc, char **argv) {
+
+ char *docname;
+
+ if (argc <= 1) {
+ printf("Usage: %s docname\n", argv[0]);
+ return(0);
+ }
+
+ docname = argv[1];
+ parseDoc (docname);
+
+ return (1);
+}
+]]>
diff --git a/doc/tutorial/includestory.xml b/doc/tutorial/includestory.xml
new file mode 100644
index 0000000..2a22c89
--- /dev/null
+++ b/doc/tutorial/includestory.xml
@@ -0,0 +1,14 @@
+<![CDATA[
+<?xml version="1.0"?>
+<story>
+ <storyinfo>
+ <author>John Fleck</author>
+ <datewritten>June 2, 2002</datewritten>
+ <keyword>example keyword</keyword>
+ </storyinfo>
+ <body>
+ <headline>This is the headline</headline>
+ <para>This is the body text.</para>
+ </body>
+</story>
+]]>
\ No newline at end of file
diff --git a/doc/tutorial/index.html b/doc/tutorial/index.html
new file mode 100644
index 0000000..eef00e3
--- /dev/null
+++ b/doc/tutorial/index.html
@@ -0,0 +1,16 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"><title>Libxml Tutorial</title><meta name="generator" content="DocBook XSL Stylesheets V1.48"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="next" href="ar01s02.html" title="Data Types"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Libxml Tutorial</th></tr><tr><td width="20%" align="left"> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="ar01s02.html">Next</a></td></tr></table><hr></div><div class="article"><div class="titlepage"><div><h1 class="title"><a name="id2759085"></a>Libxml Tutorial</h1></div><div><h3 class="author">John Fleck</h3></div><div><p class="copyright">Copyright © 2002 John Fleck</p></div><div><div class="revhistory"><table border="1" width="100%" summary="Revision history"><tr><th align="left" valign="top" colspan="2"><b>Revision History</b></th></tr><tr><td align="left">Revision 1</td><td align="left">June 4,2002</td></tr></table></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><a href="index.html#introduction">Introduction</a></dt><dt><a href="ar01s02.html">Data Types</a></dt><dt><a href="ar01s03.html">Parsing the file</a></dt><dt><a href="ar01s04.html">Retrieving Element Content</a></dt><dt><a href="ar01s05.html">Writing element content</a></dt><dt><a href="ar01s06.html">Writing Attribute</a></dt><dt>A. <a href="apa.html">Sample Document</a></dt><dt>B. <a href="apb.html">Code for Keyword Example</a></dt><dt>C. <a href="apc.html">Code for Add Keyword Example</a></dt><dt>D. <a href="apd.html">Code for Add Attribute Example</a></dt></dl></div><div class="abstract"><p><b>Abstract</b></p><p>Libxml is a freely licensed C language library for handling
+ XML, portable across a large number of platforms. This
+ tutorial provides examples of its basic functions.</p></div><div class="sect1"><div class="titlepage"><div><h2 class="title" style="clear: both"><a name="introduction"></a>Introduction</h2></div></div><p>Libxml is a C language library implementing functions for reading,
+ creating and manipulating XML data. This tutorial
+ provides example code and explanations of its basic functionality.</p><p>Libxml and more details about its use are available on <a href="http://www.xmlsoft.org/" target="_top">the project home page</a>. Included there is complete <a href="http://xmlsoft.org/html/libxml-lib.html" target="_top">
+ API documentation</a>. This tutorial is not meant
+ to substitute for that complete documentation, but to illustrate the
+ functions needed to use the library to perform basic operations.
+
+</p><p>The tutorial is based on a simple XML application I
+ use for articles I write. The format includes metadata and the body
+ of the article.</p><p>The example code in this tutorial demonstrates how to:
+ <div class="itemizedlist"><ul type="disc"><li><p>Parse the document.</p></li><li><p>Extract the text within a specified element.</p></li><li><p>Add an element and its content.</p></li><li><p>Extract the value of an attribute.</p></li><li><p>Add an attribute.</p></li></ul></div>
+
+ </p><p>Full code for the examples is included in the appendices.</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="ar01s02.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"> </td><td width="20%" align="center"> </td><td width="40%" align="right" valign="top"> Data Types</td></tr></table></div></body></html>
diff --git a/doc/tutorial/xmltutorial.xml b/doc/tutorial/xmltutorial.xml
new file mode 100644
index 0000000..be9a1ba
--- /dev/null
+++ b/doc/tutorial/xmltutorial.xml
@@ -0,0 +1,372 @@
+<?xml version="1.0"?>
+<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
+ "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" [
+<!ENTITY KEYWORD SYSTEM "includekeyword.c">
+<!ENTITY STORY SYSTEM "includestory.xml">
+<!ENTITY ADDKEYWORD SYSTEM "includeaddkeyword.c">
+<!ENTITY ADDATTRIBUTE SYSTEM "includeaddattribute.c">
+]>
+<article>
+ <articleinfo>
+ <title>Libxml Tutorial</title>
+ <author>
+ <firstname>John</firstname>
+ <surname>Fleck</surname>
+ </author>
+ <copyright>
+ <year>2002</year>
+ <holder>John Fleck</holder>
+ </copyright>
+ <revhistory>
+ <revision>
+ <revnumber>1</revnumber>
+ <date>June 4,2002</date>
+ </revision>
+ </revhistory>
+ </articleinfo>
+ <abstract>
+ <para>Libxml is a freely licensed C language library for handling
+ <acronym>XML</acronym>, portable across a large number of platforms. This
+ tutorial provides examples of its basic functions.</para>
+ </abstract>
+ <sect1 id="introduction">
+ <title>Introduction</title>
+ <para>Libxml is a C language library implementing functions for reading,
+ creating and manipulating <acronym>XML</acronym> data. This tutorial
+ provides example code and explanations of its basic functionality.</para>
+ <para>Libxml and more details about its use are available on <ulink
+ url="http://www.xmlsoft.org/">the project home page</ulink>. Included there is complete <ulink url="http://xmlsoft.org/html/libxml-lib.html">
+ <acronym>API</acronym> documentation</ulink>. This tutorial is not meant
+ to substitute for that complete documentation, but to illustrate the
+ functions needed to use the library to perform basic operations.
+<!--
+ Links to
+ other resources can be found in <xref linkend="furtherresources" />.
+-->
+</para>
+ <para>The tutorial is based on a simple <acronym>XML</acronym> application I
+ use for articles I write. The format includes metadata and the body
+ of the article.</para>
+ <para>The example code in this tutorial demonstrates how to:
+ <itemizedlist>
+ <listitem>
+ <para>Parse the document.</para>
+ </listitem>
+ <listitem>
+ <para>Extract the text within a specified element.</para>
+ </listitem>
+ <listitem>
+ <para>Add an element and its content.</para>
+ </listitem>
+ <listitem>
+ <para>Extract the value of an attribute.</para>
+ </listitem>
+ <listitem>
+ <para>Add an attribute.</para>
+ </listitem>
+ </itemizedlist>
+
+ </para>
+ <para>Full code for the examples is included in the appendices.</para>
+
+ </sect1>
+
+ <sect1 id="xmltutorialdatatypes">
+ <title>Data Types</title>
+ <para><application>Libxml</application> declares a number of datatypes we
+ will encounter repeatedly, hiding the messy stuff so you do not have to deal
+ with it unless you have some specific need.</para>
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><ulink
+ url="http://xmlsoft.org/html/libxml-tree.html#XMLCHAR">xmlChar</ulink></term>
+ <listitem>
+ <para>A basic replacement for char, a byte in a UTF-8 encoded
+ string.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <ulink url="http://xmlsoft.org/html/libxml-tree.html#XMLDOC">xmlDoc</ulink></term>
+ <listitem>
+ <para>A structure containing the tree created by a parsed doc. <ulink
+ url="http://xmlsoft.org/html/libxml-tree.html#XMLDOCPTR">xmlDocPtr</ulink>
+ is a pointer to the structure.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><ulink
+ url="http://xmlsoft.org/html/libxml-tree.html#XMLNODEPTR">xmlNodePtr</ulink>
+ and <ulink url="http://xmlsoft.org/html/libxml-tree.html#XMLNODE">xmlNode</ulink></term>
+ <listitem>
+ <para>A structure containing a single node. <ulink
+ url="http://xmlsoft.org/html/libxml-tree.html#XMLNODEPTR">xmlNodePtr</ulink>
+ is a pointer to the structure, and is used in traversing the document tree.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+
+ </sect1>
+
+ <sect1 id="xmltutorialparsing">
+ <title>Parsing the file</title>
+ <para>Parsing the file requires only the name of the file and a single
+ function call, plus error checking. Full code: <xref
+ linkend="keywordappendix" /></para>
+ <para>
+ <programlisting>
+ <co id="declaredoc" /> xmlDocPtr doc;
+ <co id="declarenode" /> xmlNodePtr cur;
+
+ <co id="parsefile" /> doc = xmlParseFile(docname);
+
+ <co id="checkparseerror" /> if (doc == NULL ) {
+ fprintf(stderr,"Document not parsed successfully. \n");
+ return;
+ }
+
+ <co id="getrootelement" /> cur = xmlDocGetRootElement(doc);
+
+ <co id="checkemptyerror" /> if (cur == NULL) {
+ fprintf(stderr,"empty document\n");
+ xmlFreeDoc(doc);
+ return;
+ }
+
+ <co id="checkroottype" /> if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
+ fprintf(stderr,"document of the wrong type, root node != story");
+ xmlFreeDoc(doc);
+ return;
+ }
+
+ </programlisting>
+ <calloutlist>
+ <callout arearefs="declaredoc">
+ <para>Declare the pointer that will point to your parsed document.</para>
+ </callout>
+ <callout arearefs="declarenode">
+ <para>Declare a node pointer (you'll need this in order to
+ interact with individual nodes).</para>
+ </callout>
+ <callout arearefs="checkparseerror">
+ <para>Check to see that the document was successfully parsed.</para>
+ </callout>
+ <callout arearefs="getrootelement">
+ <para>Retrieve the document's root element.</para>
+ </callout>
+ <callout arearefs="checkemptyerror">
+ <para>Check to make sure the document actually contains something.</para>
+ </callout>
+ <callout arearefs="checkroottype">
+ <para>In our case, we need to make sure the document is the right
+ type. "story" is the root type of my documents.</para>
+ </callout>
+ </calloutlist>
+ </para>
+ </sect1>
+
+ <sect1 id="xmltutorialgettext">
+ <title>Retrieving Element Content</title>
+ <para>Retrieving the content of an element involves traversing the document
+ tree until you find what you are looking for. In this case, we are looking
+ for an element called "keyword" contained within element called "story". The
+ process to find the node we are interested in involves tediously walking the
+ tree. We assume you already have an xmlDocPtr called <varname>doc</varname>
+ and an xmlNodPtr called <varname>cur</varname>.</para>
+
+ <para>
+ <programlisting>
+ <co id="getchildnode" /> cur = cur->xmlChildrenNode;
+ <co id="huntstoryinfo" /> while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"storyinfo"))){
+ parseStory (doc, cur);
+ }
+
+ cur = cur->next;
+ }
+
+ </programlisting>
+
+ <calloutlist>
+ <callout arearefs="getchildnode">
+ <para>Get the first child node of <varname>cur</varname>. At this
+ point, <varname>cur</varname> points at the document root, which is
+ the element "story".</para>
+ </callout>
+ <callout arearefs="huntstoryinfo">
+ <para>This loop iterates through the elements that are children of
+ "story", looking for one called "storyinfo". That
+ is the element that will contain the "keywords" we are
+ looking for. It uses the <application>libxml</application> string
+ comparison
+ function, <function><ulink
+ url="http://xmlsoft.org/html/libxml-parser.html#XMLSTRCMP">xmlStrcmp</ulink></function>. If there is a match, it calls the function <function>parseStory</function>.</para>
+ </callout>
+ </calloutlist>
+ </para>
+
+ <para>
+ <programlisting>
+void
+parseStory (xmlDocPtr doc, xmlNodePtr cur) {
+
+ <co id="anothergetchild" /> cur = cur->xmlChildrenNode;
+ <co id="findkeyword" /> while (cur != NULL) {
+ if ((!xmlStrcmp(cur->name, (const xmlChar *)"keyword"))) {
+ <co id="foundkeyword" /> printf("keyword: %s\n", xmlNodeListGetString(doc, cur->xmlChildrenNode, 1));
+ }
+ cur = cur->next;
+ }
+ return;
+}
+ </programlisting>
+ <calloutlist>
+ <callout arearefs="anothergetchild">
+ <para>Again we get the first child node.</para>
+ </callout>
+ <callout arearefs="findkeyword">
+ <para>Like the loop above, we then iterate through the nodes, looking
+ for one that matches the element we're interested in, in this case
+ "keyword".</para>
+ </callout>
+ <callout arearefs="foundkeyword">
+ <para>When we find the "keyword" element, we need to print
+ its contents. Remember that in <acronym>XML</acronym>, the text
+ contained within an element is a child node of that element, so we
+ turn to <varname>cur->xmlChildrenNode</varname>. To retrieve it, we
+ use the function <function><ulink
+ url="http://xmlsoft.org/html/libxml-tree.html#XMLNODELISTGETSTRING">xmlNodeListGetString</ulink></function>, which also takes the <varname>doc</varname> pointer as an argument. In this case, we just print it out.</para>
+ </callout>
+ </calloutlist>
+ </para>
+
+ </sect1>
+
+<sect1 id="xmltutorialwritingcontent">
+ <title>Writing element content</title>
+ <para>Writing element content uses many of the same steps we used above
+ — parsing the document and walking the tree. We parse the document,
+ then traverse the tree to find the place we want to insert our element. For
+ this example, we want to again find the "storyinfo" element and
+ this time insert a keyword. Then we'll write the file to disk. Full code:
+ <xref linkend="addkeywordappendix" /></para>
+
+ <para>
+ The main difference in this example is in
+ <function>parseStory</function>:
+
+ <programlisting>
+void
+parseStory (xmlDocPtr doc, xmlNodePtr cur, char *keyword) {
+
+ <co id="addkeyword" /> xmlNewTextChild (cur, NULL, "keyword", keyword);
+ return;
+}
+ </programlisting>
+ <calloutlist>
+ <callout arearefs="addkeyword">
+ <para>The <function><ulink
+ url="http://xmlsoft.org/html/libxml-tree.html#XMLNEWTEXTCHILD">xmlNewTextChild</ulink></function>
+ function adds a new child element at the
+ current node pointer's location in the
+ tree, specificied by <varname>cur</varname>.</para>
+ </callout>
+ </calloutlist>
+ </para>
+
+ <para>
+ Once the node has been added, we would like to write the document to
+ file. Is you want the element to have a namespace, you can add it here as
+ well. In our case, the namespace is NULL.
+ <programlisting>
+ xmlSaveFormatFile (docname, doc, 1);
+ </programlisting>
+ The first parameter is the name of the file to be written. You'll notice
+ it is the same as the file we just read. In this case, we just write over
+ the old file. The second parameter is a pointer to the xmlDoc
+ structure. Setting the third parameter equal to one ensures indenting on output.
+ </para>
+
+ </sect1>
+<!--
+ <sect1 id="xmltutorialattribute">
+ <title>Retrieving Attributes</title>
+ <para>Retrieving</para>
+ </sect1>
+-->
+
+
+ <sect1 id="xmltutorialwritingattribute">
+ <title>Writing Attribute</title>
+ <para>Writing an attribute is similar to writing text to a new element. In
+ this case, we'll add a reference <acronym>URI</acronym> to our
+ document. Full code:<xref linkend="addattributeappendix" />.</para>
+ <para>
+ A <sgmltag>reference</sgmltag> is a child of the <sgmltag>story</sgmltag>
+ element, so finding the place to put our new element and attribute is
+ simple. As soon as we do the error-checking test in our
+ <function>parseDoc</function>, we are in the right spot to add our
+ element. But before we do that, we need to make a declaration using a
+ datatype we have not seen yet:
+ <programlisting>
+ xmlAttrPtr newattr;
+ </programlisting>
+ We also need an extra xmlNodePtr:
+ <programlisting>
+ xmlNodePtr newnode;
+ </programlisting>
+ </para>
+ <para>
+ The rest of <function>parseDoc</function> is the same as before until we
+ check to see if our root element is <sgmltag>story</sgmltag>. If it is,
+ then we know we are at the right spot to add our element:
+
+ <programlisting>
+ <co id="addreferencenode" /> newnode = xmlNewTextChild (cur, NULL, "reference", NULL);
+ <co id="addattributenode" /> newattr = xmlNewProp (newnode, "uri", uri);
+ </programlisting>
+ <calloutlist>
+ <callout arearefs="addreferencenode">
+ <para>First we add a new node at the location of the current node
+ pointer, <varname>cur.</varname> using the <ulink
+ url="http://xmlsoft.org/html/libxml-tree.html#XMLNEWTEXTCHILD">xmlNewTextChild</ulink> function.</para>
+ </callout>
+ </calloutlist>
+ </para>
+
+ <para>Once the node is added, the file is written to disk just as in the
+ previous example in which we added an element with text content.</para>
+
+ </sect1>
+
+<!--
+ <appendix id="furtherresources">
+ <title>Further Resources</title>
+ <para></para>
+ </appendix>
+-->
+ <appendix id="sampledoc">
+ <title>Sample Document</title>
+ <programlisting>&STORY;</programlisting>
+ </appendix>
+ <appendix id="keywordappendix">
+ <title>Code for Keyword Example</title>
+ <para>
+ <programlisting>&KEYWORD;</programlisting>
+ </para>
+ </appendix>
+<appendix id="addkeywordappendix">
+ <title>Code for Add Keyword Example</title>
+ <para>
+ <programlisting>&ADDKEYWORD;</programlisting>
+ </para>
+ </appendix>
+<appendix id="addattributeappendix">
+ <title>Code for Add Attribute Example</title>
+ <para>
+ <programlisting>&ADDATTRIBUTE;</programlisting>
+ </para>
+ </appendix>
+</article>