I am kind of coming into this half cocked, just scanning the list here...
Below I have copied some basic function I use to implement extensions
and extension elements.
The function getStringValueFromAttribute will properly retrive a variable,
XPath expression or just the contents of an Extension Element attribute..
This should be able to easily adopted this if you are using an Extension
Function
and want to retrieve the value of a parameter.
Hopefully this is what you are after...
John G
/**
* Get the Node Value of a Stylesheet Element. This will be used to
collect
* the data value when populating a Control.....
*
* @return
*/
protected String getNodeValue( ElemExtensionCall elem )
{
Node child = elem.getFirstChild();
if (child != null)
{
return child.getNodeValue();
}
return null;
}
/**
* Resolve the Attribute Selection for the fixed attribute "select"
*
* @return
* @throws TransformerException
*/
protected String getStringValueFromSelectExpr(XSLProcessorContext
context, ElemExtensionCall elem ) throws TransformerException
{
return getStringValueFromAttribute("select", context, elem);
}
/**
* Find the Attribute named "attrib" and convert that to an XPath statement
* that can be executed.
*
* Return null if the Attribute did not exist.
*
* @param attrib
* @return
* @throws TransformerException
*/
protected static XPath getAttributeExpr( String attrib,
XSLProcessorContext context, ElemExtensionCall elem ) throws
TransformerException
{
String expr =
elem.getAttribute (attrib,
context.getContextNode(),
context.getTransformer());
if(null != expr)
{
org.apache.xpath.XPathContext xctxt
= context.getTransformer().getXPathContext();
return new XPath(
expr,
elem,
xctxt.getNamespaceContext(), XPath.SELECT);
}
return null;
}
/**
*
* Get the value of an Attribute. It will first try to treat the
attribute as an XPath
* if that fails then just return the attribute value itself.
*
* @param attrName
* @param context
* @param elem
* @return
*/
protected String getStringValueFromAttribute( String attrName,
XSLProcessorContext context, ElemExtensionCall elem )
{
XPath path;
String value = null;
try
{
path = getAttributeExpr(attrName, context, elem);
if (path != null)
{
XObject data = executeXPath(path, context, elem);
if (data != null) value = data.xstr().toString();
}
}
catch (TransformerException e)
{
value = elem.getAttribute(attrName);
}
if (value == null) value = "";
return value;
}
/**
* A helper function to execute an XPath Object.
*
* @param path
* @return
* @throws TransformerException
*/
protected static XObject executeXPath( XPath path, XSLProcessorContext
context, ElemExtensionCall elem ) throws TransformerException
{
org.apache.xpath.XPathContext xctxt
= context.getTransformer().getXPathContext();
return path.execute(xctxt, context.getContextNode(), elem);
}
Erin Harris wrote:
Hi,
I don't think the variables will have been replaced by their values
when the extension is called. Instead you could create a result tree
fragment and call an extension function passing in the result tree
fragment such as in the following example.
Stylesheet:
<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
xmlns:xalan="http://xml.apache.org/xalan";
xmlns:myclass="MyClass"
extension-element-prefixes="myclass"
version="1.0">
<xalan:component prefix="myclass" functions="process">
<xalan:script lang="javaclass" src="MyClass"/>
</xalan:component>
<xsl:variable name="var1" select="'This is variable 1.'"/>
<xsl:variable name="var2" select="'This is variable 2.'"/>
<xsl:variable name="rtf">
<elem1 number="1">
<xsl:value-of select="$var1"/>
</elem1>
<elem2 number="2">
<xsl:value-of select="$var2"/>
</elem2>
</xsl:variable>
<xsl:template match="/">
<out>
<xsl:value-of select="myclass:process($rtf)"/>
</out>
</xsl:template>
</xsl:stylesheet>
MyClass.java:
*import* org.w3c.dom.NamedNodeMap;
*import* org.w3c.dom.Node;
*import* org.w3c.dom.NodeList;
*public* *class* MyClass {
*public* *void* process(NodeList rtf) {
*for* (*int* i = 0; i < rtf.getLength(); i++) {
processNode(rtf.item(i), "");
}
}
*private* *void* processNode(Node node, String indent) {
System./out/.println(indent + "Name: " + node.getNodeName() +
", Value: " + node.getNodeValue());
NamedNodeMap map = node.getAttributes();
*for* (*int* i = 0; i < map.getLength(); i++) {
Node attr = map.item(i);
System./out/.println(indent + " Attr: " +
attr.getNodeName() + ", Value: " + attr.getNodeValue());
}
NodeList nodes = node.getChildNodes();
*for* (*int* i = 0; i < nodes.getLength(); i++) {
processNode(nodes.item(i), indent + " ");
}
}
}
The output from the processNode method is:
Name: #document, Value: null
Name: elem1, Value: null
Attr: number, Value: 1
Name: #text, Value: This is variable 1.
Name: elem2, Value: null
Attr: number, Value: 2
Name: #text, Value: This is variable 2.
Erin Harris
*Cynepnaxa <[EMAIL PROTECTED]>*
06/09/2007 10:12 PM
To
xalan-j-users@xml.apache.org
cc
Subject
Extension element with subelements
Hi, everybody!
I start to write simple extension element, but a problem occurs. I want to
access extension element's subelements in java+xalan. My xsl contains
following block of code:
<my-ext:request>
<body><xsl:value-of select="$body"/></body>
<contentType>text/html</contentType>
<metaData><![CDATA[<?xml version="1.0" encoding="utf-8"?>]]><metaData>
<xsl:value-of select="$metaData"/>
</metaData>
</metaData>
</my-ext:request>
In extension element Java-method i have "XSLProcessorContext context" and
"ElemExtensionCall elem". I can get contentType by calling for example
"elem.getFirstChild().getNextSibling().getFirstChild().getTextContent()",
but i want to access subelements by tag name(for example, by
elem.getElementsByTagName("metadata"), or XPath). I have no idea how to
access in java content of $body variable and xml - encapsulated $metaData.
All google - examples shining no light. Is simple xslt - subelements
access
method exist? Big thanx for help.
P.S. Sorry for my English. I hope you understand me.
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Eye Catching Solutions Inc.
18314 Carlwyn Drive
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