You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
103 lines
3.8 KiB
103 lines
3.8 KiB
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
|
|
<HTML>
|
|
<HEAD>
|
|
<TITLE>Mini-XML Programmers Manual, Version 2.2.1</TITLE>
|
|
<META NAME="author" CONTENT="Michael Sweet">
|
|
<META NAME="copyright" CONTENT="Copyright 2003-2005">
|
|
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-iso-8859-1">
|
|
<LINK REL="Start" HREF="index.html">
|
|
<LINK REL="Contents" HREF="toc.html">
|
|
<LINK REL="Prev" HREF="3MoreMiniXMLProgrammingTechniques.html">
|
|
<LINK REL="Next" HREF="SaveCallbacks.html">
|
|
<STYLE TYPE="text/css"><!--
|
|
BODY { font-family: serif }
|
|
H1 { font-family: sans-serif }
|
|
H2 { font-family: sans-serif }
|
|
H3 { font-family: sans-serif }
|
|
H4 { font-family: sans-serif }
|
|
H5 { font-family: sans-serif }
|
|
H6 { font-family: sans-serif }
|
|
SUB { font-size: smaller }
|
|
SUP { font-size: smaller }
|
|
PRE { font-family: monospace }
|
|
--></STYLE>
|
|
</HEAD>
|
|
<BODY>
|
|
<A HREF="toc.html">Contents</A>
|
|
<A HREF="3MoreMiniXMLProgrammingTechniques.html">Previous</A>
|
|
<A HREF="SaveCallbacks.html">Next</A>
|
|
<HR NOSHADE>
|
|
<H2><A name="LOAD_CALLBACKS">Load Callbacks</A></H2>
|
|
<P><A href="#LOAD_XML">Chapter 2</A> introduced the <A href="mxmlLoadFile.html#mxmlLoadFile">
|
|
<TT>mxmlLoadFile()</TT></A> and <A href="mxmlLoadString.html#mxmlLoadString">
|
|
<TT>mxmlLoadString()</TT></A> functions. The last argument to these
|
|
functions is a callback function which is used to determine the value
|
|
type of each data node in an XML document.</P>
|
|
<P>Mini-XML defines several standard callbacks for simple XML data
|
|
files:</P>
|
|
<UL>
|
|
<LI><TT>MXML_INTEGER_CALLBACK</TT> - All data nodes contain
|
|
whitespace-separated integers.</LI>
|
|
<LI><TT>MXML_OPAQUE_CALLBACK</TT> - All data nodes contain opaque
|
|
strings ("CDATA").</LI>
|
|
<LI><TT>MXML_REAL_CALLBACK</TT> - All data nodes contain
|
|
whitespace-separated floating-point numbers.</LI>
|
|
<LI><TT>MXML_TEXT_CALLBACK</TT> - All data nodes contain
|
|
whitespace-separated strings.</LI>
|
|
</UL>
|
|
<P>You can provide your own callback functions for more complex XML
|
|
documents. Your callback function will receive a pointer to the current
|
|
element node and must return the value type of the immediate children
|
|
for that element node: <TT>MXML_INTEGER</TT>, <TT>MXML_OPAQUE</TT>, <TT>
|
|
MXML_REAL</TT>, or <TT>MXML_TEXT</TT>. The function is called<I> after</I>
|
|
the element and its attributes have been read, so you can look at the
|
|
element name, attributes, and attribute values to determine the proper
|
|
value type to return.</P>
|
|
|
|
<!-- NEED 2in -->
|
|
<P>The following callback function looks for an attribute named "type"
|
|
or the element name to determine the value type for its child nodes:</P>
|
|
<PRE>
|
|
/*
|
|
* 'type_cb()' - XML data type callback for mxmlLoadFile()...
|
|
*/
|
|
|
|
mxml_type_t /* O - Data type */
|
|
type_cb(mxml_node_t *node) /* I - Element node */
|
|
{
|
|
const char *type; /* Type string */
|
|
|
|
|
|
/*
|
|
* You can lookup attributes and/or use the element name, hierarchy, etc...
|
|
*/
|
|
|
|
if ((type = mxmlElementGetAttr(node, "type")) == NULL)
|
|
type = node->value.element.name;
|
|
|
|
if (!strcmp(type, "integer"))
|
|
return (MXML_INTEGER);
|
|
else if (!strcmp(type, "opaque"))
|
|
return (MXML_OPAQUE);
|
|
else if (!strcmp(type, "real"))
|
|
return (MXML_REAL);
|
|
else
|
|
return (MXML_TEXT);
|
|
}
|
|
</PRE>
|
|
<P>To use this callback function, simply use the name when you call any
|
|
of the load functions:</P>
|
|
<PRE>
|
|
FILE *fp;
|
|
<A href="mxmlnodet.html#mxml_node_t">mxml_node_t</A> *tree;
|
|
|
|
fp = fopen("filename.xml", "r");
|
|
tree = <A href="mxmlLoadFile.html#mxmlLoadFile">mxmlLoadFile</A>(NULL, fp, <B>type_cb</B>);
|
|
fclose(fp);
|
|
</PRE>
|
|
<HR NOSHADE>
|
|
<A HREF="toc.html">Contents</A>
|
|
<A HREF="3MoreMiniXMLProgrammingTechniques.html">Previous</A>
|
|
<A HREF="SaveCallbacks.html">Next</A>
|
|
</BODY>
|
|
</HTML>
|
|
|