Create custom tag extending XSLT using .NET

Question

Is there a way to create custom tag extending XSLT in a similar way to custom function?

ie (in my xslt file):

<xsl:template match="/">
<div>
  <my:customTag items="3" classname="foo"/>
</div>
</xsl:template>

expected output:

<div>
  <ul class="foo">
    <li>...</li>
    <li>...</li>
    <li>...</li>
  </ul>
<div>

Currently I'm doing this:

<xsl:template match="/">
<div>
  <xsl:copy-of select="my:customFunc(3,'foo')" />
</div>
</xsl:template>

and my customFunc in vb code do something like this:

Public Function customFunc(ByVal n As Integer, ByVal classname as String) As System.Xml.XmlNode
            Dim newNode As System.Xml.XmlNode
            Dim doc As System.Xml.XmlDocument = New System.Xml.XmlDocument()
            Dim xmlContent As String = "<ul class=""" + classname + """>"

            For v As Integer = 0 To n
                xmlContent += "<li>" + someComplicatedCalc(n) + "</li>"
            Next
            xmlContent += "</ul>"


            doc.LoadXml(xmlContent)
            newNode = doc.DocumentElement

            Return newNode
        End Function

but I want to use tags instead of functions.

Hi, I've edited my post, take a look at it. I want to call my function but using a tag like syntax. — Lookhill, Feb 24 '16 at 16:39

Martin Honnen · Answer 1 · 2016-02-24T15:43:38.117

1

I am not aware of any support for this feature called custom extension elements with Microsoft's XslCompiledTransform and other processors, like XmlPrime or like Saxon (http://saxonica.com/html/documentation9.6/extensibility/instructions.html) don't seem to support it either with .NET.

edited Feb 24 '16 at 15:43

answered Feb 24 '16 at 15:28

Martin Honnen

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Dan Field · Answer 2 · 2016-02-24T15:55:53.627

If you're looking for a way to replace your VB function with just XSLT, you could do something like this:

<xsl:template match="my:customTag">
    <ul class="{@classname}">
      <xsl:call-template name="expand_customTag">
        <xsl:with-param name="i" select="1" />
        <xsl:with-param name="count" select="@items" />
      </xsl:call-template>
    </ul>
</xsl:template>
<xsl:template name="expand_customTag">
    <xsl:param name="i" />
    <xsl:param name="count" />
    <il>....</il>
    <xsl:if test="$i &lt; $count">
      <xsl:call-template name="expand_customTag">
        <xsl:with-param name="i" select="$i + 1" />
        <xsl:with-param name="count" select="$count" />
      </xsl:call-template>
    </xsl:if>
</xsl:template>

The idea is using a recursive template to produce your <il> elements, and this would make your XSLT more portable to other XSLT processors.

score 1 · Answer 3 · answered Feb 24 '16 at 16:02

1

If you want to use your existing VB.Net code but have nicer syntax in your source XML try adding this template to your stylesheet.

<xsl:template match="my:customTag">
  <xsl:copy-of select="my:customFunc(@items,@classname)" />
</xsl:template>

The xpath selector will use your <my:customTag items="3" classname="foo"/>

answered Feb 24 '16 at 16:02

Matthew Whited

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Thanks, but I'm trying to insert the custom tag in my XSLT, not in my XML. – Lookhill Feb 24 '16 at 16:30
Are you trying to output a custom tag or use XSLT extension elements? – Matthew Whited Feb 24 '16 at 16:48
I'm trying to use XSLT extension element, but with no luck. Basically I want the customTag to be replaced with its vb output during xslt transformation. – Lookhill Feb 24 '16 at 16:57

Create custom tag extending XSLT using .NET

3 Answers3