WiX4: Custom BA for showing MSI UI

[oleg-shilo]

Not sure how the new WiX API is handling the following scenario.
I need to show MSI UI while executing the bundle with the custom managed BA.

<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:netfx="http://wixtoolset.org/schemas/v4/wxs/netfx" xmlns:bal="http://wixtoolset.org/schemas/v4/wxs/bal">
  <Bundle Name="My Product Bundle" UpgradeCode="6f330b47-2577-43ad-9095-1861bb25889a" Version="1.0.0.0" >
    <BootstrapperApplication>
      <bal:WixManagedBootstrapperApplicationHost />
      <Payload SourceFile="BA.dll" />
      <Payload Name="WixToolset.Mba.Host.config" SourceFile="BootstrapperCore.config" />
      <Payload SourceFile="bin\Debug\net472\win-x86\mbanative.dll" />
      <Payload SourceFile="bin\Debug\net472\win-x86\WixToolset.Mba.Core.dll" />
    </BootstrapperApplication>

    <Chain>
      <MsiPackage Id="MyProductPackageId" 
                  SourceFile="My Product.msi" 
                  bal:DisplayInternalUICondition="WixBundleAction = 6" 
                  bal:PrereqPackage="yes">
      </MsiPackage>
    </Chain>
  </Bundle>
</Wix>

The code above works if the BA is WixStandardBootstrapperApplication however if it is a custom BA then bal:DisplayInternalUICondition has no impact.

Not sure if DisplayInternalUICondition needs to have different value in case of custom BA.

Is there some way around?

[Torchok19081986]

i found link from gitbhub and WixTeam itself. #7170. Can you investigate it ?

[oleg-shilo]

With a hint from WiX team I was able to solve it.
In a nutshell, it's not possible (at least now) to control this behaviour from outside custom BA (e.g. a magic attribute of MsiPackage)
The solution is to set the UI in the appropriate BootstrapperApplication event:

 this.PlanMsiPackage += (object sender, PlanMsiPackageEventArgs e) =>
        {
            if (e.PackageId == "MyProductPackageId")
                e.UiLevel = e.Action == ActionState.Uninstall ?
                                INSTALLUILEVEL.ProgressOnly :
                                INSTALLUILEVEL.Full;
        };