XPath in MSBuild (SDC) and WIX - msbuild

Question

Fresh Asking of this Question->
I have a WIX file that I need to modify using MSBuild. It starts like this:
<?xml version="1.0" encoding="UTF-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi"
xmlns:iis="http://schemas.microsoft.com/wix/IIsExtension">
<?--... Various Removed Params ...-->
<Product Id='$(var.ProductCode)'
UpgradeCode='$(var.UpgradeCode)'
Name='$(var.AppName)' Language="1033" Version='$(var.ProductVersion)'
Manufacturer='$(var.Manufacturer)'>
<Package Id='$(var.PackageCode)' InstallerVersion="200"
Compressed="yes" />
<?--... More of the WIX XML file ...-->
<iis:WebApplication Id='STWebApp' Name='MyWebSite' Isolation='medium' />
<?--... Rest of the WIX XML file ...-->
My problem is the SDC tasks can't seem to reference any of the xml nodes that are WIX related. For example:
<XmlFile.SetAttribute Path="$(MSBuildProjectDirectory)\TestProduct.wxs"
XPath="//iis:WebApplication" Namespaces="#(Namespaces)"
Name="Name" Value="$(VersionTag)"/>
works just fine because it does not use any Wix nodes (just an iis one), but if I use the full XPath path to it (/Wix/Product/iis:WebApplication) the task returns:
Could not find resource string No matches found for XPath expression
This is not a problem till I want to reference a Directory node (/Wix/Product/Directory/Directory/Directory/Directory[#Id='STWebSiteDir'])
I have tried using the full XPath and the shorter //Directory[#Id='STWebSiteDir']. I have tried single quotes and double quotes, I have tried adding the WIX namespace to the call (with no prefix).
<ItemGroup>
<Namespaces Include="http://schemas.microsoft.com/wix/IIsExtension">
<Prefix>iis</Prefix>
<Uri>http://schemas.microsoft.com/wix/IIsExtension</Uri>
</Namespaces>
<Namespaces Include="http://schemas.microsoft.com/wix/2006/wi">
<Prefix></Prefix>
<Uri>http://schemas.microsoft.com/wix/2006/wi</Uri>
</Namespaces>
</ItemGroup>
I have even tried to just get a reference to /Wix/Product and even that fails:
<XmlFile.SetAttribute Path="$(MSBuildProjectDirectory)\TestProduct.wxs"
XPath="/Wix/Product" Namespaces="#(Namespaces)"
Name="Name" Value="MODIFIED"/>
I am clearly missing something. Anyone with a hint on where to go to get this to work?
Vaccano

Answer 1

Can you just define the variables on the command line to the preprocessor?
candle -dVariableName=ValueForVariable
That might be much easier.

Answer 2

Have you included the Wix default namespace in #(Namespaces)?

Answer 3

<ItemGroup>
<Namespaces Include="http://schemas.microsoft.com/wix/IIsExtension">
<Prefix>iis</Prefix>
<Uri>http://schemas.microsoft.com/wix/IIsExtension</Uri>
</Namespaces>
<Namespaces Include="http://schemas.microsoft.com/wix/2006/wi">
<Prefix>wis</Prefix>
<Uri>http://schemas.microsoft.com/wix/2006/wi</Uri>
</Namespaces>
</ItemGroup>
you should add a prefix for wi namespace too,after that it can ok,i have test it.

Answer 4

OK, so here is the answer:
The namespace prefix needed to be missing for the wix part, not just left empty
<ItemGroup>
<Namespaces Include="http://schemas.microsoft.com/wix/IIsExtension">
<Prefix>iis</Prefix>
<Uri>http://schemas.microsoft.com/wix/IIsExtension</Uri>
</Namespaces>
<Namespaces Include="http://schemas.microsoft.com/wix/2006/wi">
<Uri>http://schemas.microsoft.com/wix/2006/wi</Uri>
</Namespaces>
</ItemGroup>
And then you need to add a prefix value to the wix namespace in the file. I used tst.
Vaccano