TransformXml task with InsertAfter - How to use function?

Question

I'm trying to use the <TransformXml> task in my web projects (.csproj/.vbproj) to Transform configuration files and other XML files. I use an msbuild script (powershell) to build and package my code and generate environment-based transformed configuration and XML files.

This all works perfectly for simple usages such as Match, Condition, SetAttributes and so on, but I've recently tried to be a bit clever and use an XPath locator to find the last node in a group of nodes in order to only set the attributes of that last node. Additionally, I want to insert a new node after the last node, with some extra attributes.

When trying this syntax:

<parent>
    <a xdt:Transform="SetAttributes(from)" xdt:Locator="XPath(/a[ancestor-or-self::section[last()]])" from="20130522" />
          <a xdt:Transform="SetAttributes(to)" xdt:Locator="XPath(/a[ancestor-or-self::section[last()]])" to="20130630" />
          <a xdt:Transform="InsertAfter(XPath(/a[ancestor-or-self::section[last()]]))" from="20130701" to="20140101" />
</parent>

on XML (shortened) that looks approximately like this:

<parent>
  <a from="xxx1" to="yyy1">
    <one>one</one>
    <two>two</two>
  </a>
  <a from="xxx2" to="yyy2">
    <one>one</one>
    <two>two</two>
  </a>
  <a from="xxx3" to="yyy3">
    <one>one</one>
    <two>two</two>
  </a>
</parent>

... I get the familiar (and expected) error

Namespace Manager or XsltContext needed. This query has a prefix, variable, or user-defined function.

All the answers I can find for this revolve around using code to specify a Namespace manager, which makes perfect sense - but I have no code for this process, it's all within the scope of a TransformXml task and plain XML. I don't know which part of the XPath query is causing this error to occur, or how I can specify the type of task I need to run.

How can I accomplish this? Is it even possible to do this type of node manipulation within a transform?

Thanks

Edit: I can now see that the error is occurring on the InsertAfter call and not the SetAttributes - so it's this part that appears to be causing the issue.

Answer 1

Ok, so this was dead simple to resolve. "InsertAfter" takes an XPath expression directly and doesn't require the XPath function specifying - so this was a pretty simple fix! I'll leave this question up incase anyone is ever as impatient as I am :)

e.g. InsertAfter(/parent/a[last()])