Hi Paul,
Here's code I use to achieve this effect. The method is called doSelect
(and the param string "selectStr") because it should behave in the same
manner as the select attribute in an <xsl:value-of select="..."/> tag,
ie be evaluated for its string value.
/**
* evaluate a string containing an arbitrary expression which may
* contain variable references, xpath expressions, calls to
functions,
* etc.
*
* @return a string which represents the result of the expression.
*/
private static String doSelect(
XSLProcessorContext procContext,
ElemExtensionCall extensionElement,
String selectStr)
throws TransformerException
{
String nodeText = "";
if ((selectStr != null && selectStr.length() != 0))
{
TransformerImpl transformer = procContext.getTransformer();
XPathContext xpContext = transformer.getXPathContext();
try
{
xpContext.pushNamespaceContext(extensionElement);
int current = xpContext.getCurrentNode();
xpContext.pushCurrentNodeAndExpression(current,current);
XPath dynamicXPath = new XPath(
selectStr,
xpContext.getSAXLocator(),
xpContext.getNamespaceContext(),
XPath.SELECT,
transformer.getErrorListener());
Expression expression = dynamicXPath.getExpression();
XObject xobj1 = expression.execute(xpContext);
xpContext.popCurrentNodeAndExpression();
xpContext.popNamespaceContext();
nodeText = xobj1.toString();
}
catch(TransformerException te)
{
String msg =
"failed to evaluate expression at line ["
+ xpContext.getSAXLocator().getLineNumber()
+ "] : " + te.getMessage();
reportError(procContext, extensionElement, msg);
return "";
}
}
return nodeText;
}
I then call this from my extension methods, like this:
/**
* Evaluate the specified expression, and if it is false then report
* an error and throw an exception which will terminate stylesheet
* processing.
*/
public static void assertExpr(
XSLProcessorContext procContext,
ElemExtensionCall extensionElement)
throws TransformerException
{
// note that while the Node.getAttribute method never returns
null,
// the ElemExtensionCall.getAttribute method does!
String selectStr = extensionElement.getAttribute("select");
String message = extensionElement.getAttribute("message");
// execute the xpath command in select (if any)
String nodeText = doSelect(procContext, extensionElement,
selectStr);
if (!nodeText.equals("true"))
{
reportError(procContext, extensionElement, message);
}
}
I hope this is what you were looking for...
Regards,
Simon
On Fri, 2002-11-29 at 04:48, Paul Brady wrote:
> I get the same result when using v2.4.1.
> The following piece of code works when evaluating local variables, but not
> for parameters. Is there a similar way to evaluate paramteters?
>
> XPathContext xctxt = context.getTransformer().getXPathContext();
> XPath myxpath = new XPath("$VarName", elem, xctxt.getNamespaceContext(), 0);
> XObject xobj = myxpath.execute(xctxt, context.getContextNode(), elem);
> String strVarVal = xobj.str();
>
> Thanks,
>
> Paul
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Sent: 27 November 2002 17:59
> To: Paul Brady
> Cc: '[EMAIL PROTECTED]'
> Subject: Re: Passing params to an extension element
>
> We fixed a lot of extension problems in Xalan 2.4.1. Please try with this
> latest release to see if it fixes your problem.
>
> Morris Kwan
> XSLT Development
> IBM Toronto Lab
> Tel: (905)413-3729
> Email: [EMAIL PROTECTED]
>
>
>
>
>
> Paul Brady
>
> <[EMAIL PROTECTED] To:
> "'[EMAIL PROTECTED]'" <[EMAIL PROTECTED]>
> la.com> cc:
>
> Subject: Passing params to
> an extension element
> 11/27/2002 12:30
>
> PM
>
>
>
>
>
>
>
>
> I'm trying to pass an <xsl:param> into an extension element using Xalan
> 2.3.1.
>
> If I do something like:
> <xsl:template name="DocletContentBody">
> <xsl:param name="docletTemplate"/>
>
> <dynamicTemplate:dynamicCallTemplate name="$docletTemplate">
> <xsl:call-template name="doesntMatter">
> </xsl:call-template>
> </dynamicTemplate:dynamicCallTemplate>
> </xsl:template>
>
> where dynamicTemplate is my extension element, the value of the name
> attribute evaluates to "$docletTemplate" rather than the value of the
> parameter.
>
> Any ideas?
>
> Paul.
>
>
>
--
Simon Kitching <[EMAIL PROTECTED]>
