I am trying to pass some parameters like
  <xsl:param name="callbackWorkflowId"/>

which is set from the Java XSLT transformer. I am trying to use it inside template match e.g.
  <xsl:template match="xhtml:form">
    <xsl:copy>
      <xsl:apply-templates select="@*"/>
        <input type="hidden" name="_TaskDetailsPortlet_WAR_JasperPortal_workflo wInstanceId" value="<xsl:value-of select="$callbackWorkflowId"/>";/>
    </xsl:copy>
  </xsl:template>

But I get transformation error:
The value of attribute "value" associated with an element type "null" must not contain the '<' character.
ERROR: 'The value of attribute "value" associated with an element type "null" must not contain the '<' character.'
FATAL ERROR: 'Could not compile stylesheet'

It looks like I can't use xsl:value-of within quotes of value attribute. I tried outside value tag and it works. What's the best way to do this? Thanks in advance.

Try using <xsl:text> before and after <xsl:value-of select="$callbackWorkflowId"/>

Try this:

<input type="hidden" name="_TaskDetailsPortlet_WAR_JasperPortal_workflo wInstanceId" value="{$callbackWorkflowId}"/>

They are called Attribute Template Values.

/- Sam Judson : Wrox Technical Editor -/

XML doesn't allow elements to be nested inside attributes (and XSLT is XML...)

So use an attribute value template:

<input type="hidden" name="_TaskDetailsPortlet_WAR_JasperPortal_workflo wInstanceId"
value="{$callbackWorkflowId}"/>

You can nest any XPath expression between the curly braces.

Michael Kay
http://www.saxonica.com/
Author, XSLT 2.0 and XPath 2.0 Programmer's Reference

{$tag} syntax worked. Thanks.