filter resources example script for android gradle

filter_resources

    def filterVariant = { variantToFilter, filterTask->
        def variantRes = android.sourceSets."${variantToFilter.toLowerCase()}".res
        variantRes.srcDirs.each{ resDir->
            def filterOutput = "${buildDir}/res-filter"
            if (resDir.toString().contains(filterOutput)) {
                return
            }

            // remove all the add-resource nodes
            filterTask.from fileTree(dir: resDir, include: 'values*/*.xml')
            filterTask.filter { String line ->
                line.contains('<add-resource') ? '' : line
            }


            // @workaround https://code.google.com/p/android/issues/detail?id=64957
            filterTask.from fileTree(dir: resDir, exclude: 'values*/*.xml')
            filterTask.into "${filterOutput}/${variantToFilter}"
            variantRes.srcDirs = [] << "${filterOutput}/${variantToFilter}"

            // proper way shall be this, google is still working on it
//            filterTask.from fileTree(dir: resDir, include: 'values*/*.xml')
//            filterTask.into "${filterOutput}/${variantToFilter}"
//            variantRes.exclude "${resDir}/values*/*.xml"
//            variantRes.srcDirs = variantRes.srcDirs << "${filterOutput}/${variantToFilter}"
        }
    }
    project.task('filterMainResources', type: Copy) {
        filterVariant 'main', it
    }
    android.libraryVariants.all{ variant ->
        project.task("filter${variant.name}Resources", type: Copy) { filterTask ->
            filterVariant "${variant.name}", filterTask
            filterTask.dependsOn "filterMainResources"
        }
        variant.mergeResources.dependsOn("filter${variant.name}Resources")
    }