Cannot set package name with AndroidManifestPlaceholders

[ArrowCase]

Steps to Reproduce

1. Create a Xamarin.Forms or Xamarin.Android solution.
2. Edit the Android csproj file to add the following to a PropertyGroup:

<AndroidManifestPlaceholders>bundleId=com.somebody.something</AndroidManifestPlaceholders>

3. Edit AndroidManifest.xml and change the package attribute of the root element as follows:

package="${bundleId}"

4. Build the project.

repro_project.zip

Expected Behavior

The project is built with a package ID of com.somebody.something.

Actual Behavior

The project is built with a package ID of x__bundleId_.x__bundleId_.

Version Information

VS 16.2 Preview 2, everything latest preview.

[dellis1972]

I have managed to repo this issue. Will take a look

[dellis1972]

looking at the code we have AndroidManifestPlaceholders was not designed to replace the package part of the AndroidManifest.xml. It was mostly designed to deal with placeholders in the application element and its children.

The reason we get x__bundleId_ is because a method called CanonicalizePackageName replaces all non valid characters in the package attribute with and _ and then prefix that with an x. See [1] for the code. This is by design, it is because android has strict character limits on the package attribute.

So to implement this we will need to introduce a new feature.
Currently AndroidManifestPlaceholders won't work since its only applied at the point when we process the AndroidManifest.xml and place it into the $(IntermediateOutputPath)android directory. Prior to this we have already used to to get the package Name for the final Apk and other parts of the build (such as wear apps).

[1] https://github.com/xamarin/xamarin-android-tools/blob/5c5f74f45e9c2dc5a2f829e811701f3b74b0adc1/src/Xamarin.Android.Tools.AndroidSdk/AndroidAppManifest.cs#L56