How to replace strings resources with Android Gradle

Question

I made a new app with gradle in Android Studio, and now I need to make about 10 versions with different package names and values in resources. I made custom flavors as in ex

Answer 1

I was trying to get similar functionality as Maven resource filtering. This is what I came up with. My solution could use some changes to be more robust (i.e. pulling from a properties file, etc).

My example just shows how to replace a single value, which is all that I needed. The variables follow the ${some.property} convention. This solution also works with product flavors that have their own resource files.

import org.apache.tools.ant.filters.*
...
android.applicationVariants.all{ variant ->
    // Perform resource filtering
    variant.mergeResources.doLast {
        filterResources(variant)
    }
}

def filterResources(buildVariant) {

    //Setup temp directory to filter the resources
    File resFiltered = file("${buildDir}/res/all/filtered/${buildVariant.dirName}")
    if(resFiltered.exists()){
        resFiltered.delete()
    }

    //Copy and filter the resources.
    copy {
        from(buildVariant.processResources.resDir) {
            include '**/*.xml'

            //Could be improved upon to pull from a properties file, etc.
            ant.properties['app.version'] = project.version

            filter(ExpandProperties, project: ant.project)

        }
        from(buildVariant.processResources.resDir) {
            exclude '**/*.xml'
        }

        into resFiltered

    }

    //Delete all the original resource files
    file(buildVariant.processResources.resDir).deleteDir()
    //Replace with the filtered ones.
    resFiltered.renameTo(file(buildVariant.processResources.resDir))
    //Delete the original 'filtered' directory
    file( "${buildDir}/res/all/filtered").deleteDir()
}

Example in strings.xml

 ...
 ${app.version}
 ...