WiX Installer: using xslt with heat.exe to update attributes

You have two different defined namespaces:

1. In XML: http://schemas.microsoft.com/wix/2006/wi
2. In XSLT: http://schemas.microsoft.com/wix/2006/wix

As far as I know, correct namespace for WiX is http://schemas.microsoft.com/wix/2006/wi. So you should change your XSLT.

XSLT:

<xsl:stylesheet version="1.0"
            xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
            xmlns:msxsl="urn:schemas-microsoft-com:xslt"
            exclude-result-prefixes="msxsl"
            xmlns:wix="http://schemas.microsoft.com/wix/2006/wi"
            xmlns:my="my:my">

    <xsl:output method="xml" indent="yes" />

    <xsl:strip-space elements="*"/>

    <xsl:template match="@*|node()">
        <xsl:copy>
            <xsl:apply-templates select="@*|node()"/>
        </xsl:copy>
    </xsl:template>

    <xsl:template match='wix:Wix/wix:Fragment/wix:DirectoryRef/wix:Component/wix:File[@Id and not (@Id = "EmailGenerationService.exe")]'>
        <xsl:copy>
            <xsl:apply-templates select="@*"/>
            <xsl:attribute name="KeyPath">
                <xsl:text>no</xsl:text>
            </xsl:attribute>
        </xsl:copy>
    </xsl:template>
</xsl:stylesheet>

Input XML:

<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
    <Fragment>
        <DirectoryRef Id="INSTALLLOCATION">
            <Component Id="Dollar.Common.dll" Guid="{2BCD0767-2383-47CF-B1BF-325FA4A3264F}">
                <File Id="Dollar.Common.dll" KeyPath="yes" Source="$(var.FileSource)\Dollar.Common.dll" />
            </Component>
            <Component Id="Dollar.Common.Exceptions.dll" Guid="{B7238091-76D1-42F5-A3B4-A539DFF3BD92}">
                <File Id="Dollar.Common.Exceptions.dll" KeyPath="yes" Source="$(var.FileSource)\Dollar.Common.Exceptions.dll" />
            </Component>
            <Component Id="Dollar.Common.Exceptions.pdb" Guid="{43711979-747D-49C9-BAE4-ECD44FAF5E67}">
                <File Id="Dollar.Common.Exceptions.pdb" KeyPath="yes" Source="$(var.FileSource)\Dollar.Common.Exceptions.pdb" />
            </Component>
            <Component Id="Dollar.Common.Logging.dll" Guid="{59F9ABF3-5F68-410C-BC96-0556282F1E04}">
                <File Id="Dollar.Common.Logging.dll" KeyPath="yes" Source="$(var.FileSource)\Dollar.Common.Logging.dll" />
            </Component>
        </DirectoryRef>
    </Fragment>
</Wix>

Output XML:

<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
  <Fragment>
    <DirectoryRef Id="INSTALLLOCATION">
      <Component Id="Dollar.Common.dll" Guid="{2BCD0767-2383-47CF-B1BF-325FA4A3264F}">
        <File Id="Dollar.Common.dll" Source="$(var.FileSource)\Dollar.Common.dll" KeyPath="no" />
      </Component>
      <Component Id="Dollar.Common.Exceptions.dll" Guid="{B7238091-76D1-42F5-A3B4-A539DFF3BD92}">
        <File Id="Dollar.Common.Exceptions.dll" Source="$(var.FileSource)\Dollar.Common.Exceptions.dll" KeyPath="no" />
      </Component>
      <Component Id="Dollar.Common.Exceptions.pdb" Guid="{43711979-747D-49C9-BAE4-ECD44FAF5E67}">
        <File Id="Dollar.Common.Exceptions.pdb" Source="$(var.FileSource)\Dollar.Common.Exceptions.pdb" KeyPath="no" />
      </Component>
      <Component Id="Dollar.Common.Logging.dll" Guid="{59F9ABF3-5F68-410C-BC96-0556282F1E04}">
        <File Id="Dollar.Common.Logging.dll" Source="$(var.FileSource)\Dollar.Common.Logging.dll" KeyPath="no" />
      </Component>
    </DirectoryRef>
  </Fragment>
</Wix>

I won't answer your original question. :)

I have read that I nned to set the keyPath to “no” for all my files, with the exception of the .exe

I think you were mislead. In reality the ServiceInstall table has a column Component_, and according to MSDN:

to install this service using the InstallService table, the KeyPath for this component must be the executable file for the service.

It doesn't mean the non-exe files in other components should have @KeyPath='no'. It just says that the EXE file of the service should reside in a separate component and must be the key path of it.

The key path is a very important concept of the MSI technology. You can read more about it here, see the description of the KeyPath column.

Now, if we get back to your original question - no, you don't have to tweak the heat output the way you mentioned. It will generate the WiX authoring you need by default.

May I suggest a different approach?

<xsl:template match="@KeyPath[parent::wix:File[parent::wix:Component[parent::wix:DirectoryRef[parent::wix:Fragment[parent::wix:Wix]]]] and . != 'EmailGenerationService.exe']">
        <xsl:attribute name="KeyPath">
            <xsl:value-of select="'no'"/>
        </xsl:attribute>
</xsl:template>

Just change your template matching to the above and you should have the correct result.