Unpack WIX Burn bundle

The key thing to know is that there is a BootstrapperCore.dll in the WiX binaries that defines a BootstrapperApplication class that handles the integration with the Burn engine. I needed to create my own derived class and override the 'Run' method to launch my custom UI.

It was also helpful to use the WixBA project that defines the UI for the WiX bootstrapper as a reference for using the BootstrapperApplication class (src\Setup\WixBA\WixBA.csproj).

The markup I used to reference my custom bootstrapper DLL file is:

<BootstrapperApplicationRef Id="ManagedBootstrapperApplicationHost" >
  <Payload SourceFile="$(var.InstallSourceResources)Bootstrapper\FusionInstallUX.dll"/>
  <Payload Id="FusionInstallUX.config"
           SourceFile="$(var.InstallSourceResources)Bootstrapper\FusionInstallUX.BootstrapperCore.config"
           Name="BootstrapperCore.config" Compressed="yes"/>
</BootstrapperApplicationRef>

The configuration file consists of:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
        <sectionGroup
            name="wix.bootstrapper"
            type="Microsoft.Tools.WindowsInstallerXml.Bootstrapper.BootstrapperSectionGroup, BootstrapperCore">

            <section
                name="host"
                type="Microsoft.Tools.WindowsInstallerXml.Bootstrapper.HostSection, BootstrapperCore" />
        </sectionGroup>
    </configSections>

    <startup useLegacyV2RuntimeActivationPolicy="true">
        <supportedRuntime version="v4.0" />
    </startup>

    <wix.bootstrapper>
        <host assemblyName="FusionInstallUX">
            <supportedFramework version="v4\Full" />
            <supportedFramework version="v4\Client" />
        </host>
    </wix.bootstrapper>
</configuration>

I also followed other examples and appended

[assembly: BootstrapperApplication(typeof([name of class deriving from BootstrapperApplication]))]

to the AssemblyInfo.cs file.

And lastly, Stack Overflow question Specify the INSTALLLOCATION of packages in WiX inside the Burn managed bootstrapper describes how to set and use Burn variables to help drive the installation.

Armed with this information I am now prepared to wreak havoc on the world with my very own custom Bootstrapper application!

There is a fourth option, a useful lightweight hack, identified by Vijay Kotecha (see http://vijayskotecha.blogspot.com/2013/07/wix-bootstrapper-custom-action.html),...

Essentially, build an <ExePackage> around a pass-through .bat or .cmd batch file. The batch/command file contains the single line '%*' which re-executes all of the command line arguments as a first class command.

Thus:

<ExePackage ... SourceFile="SourcePath\WixCustomAction.cmd"
    InstallCommand="my_custom_action.exe my_custom_parameters" />
<ExePackage ... SourceFile="SourcePath\WixCustomAction.cmd"
    InstallCommand="my_next_action.exe my_next_parameters" />

Where WixCustomAction.cmd is a file containing only '%*'.

These <ExePackages> can be placed into the <Bundle><Chain> successively as needed using different InstallCommands as needed.