gistfile1.groovy

// need to create a signing task for all possible output
variant.outputs.each { output ->
    // create a signing task for this
    SignApk signTask = project.tasks.create("sign${output.name.capitalize()}MyApk", SignApk)

    // setup task info
    signTask.conventionMapping.inputFile = { output.packageApplication.outputFile }
    signTask.outputFile = project.file("$project.buildDir/outputs/apk/${project.archivesBaseName}-${output.baseName}-unaligned.apk")
    // other configuration of the signing task go here.

    // setup task dependencies
    signTask.dependsOn output.packageApplication

    if (variant.buildType.isZipAlign()) {
        // Because the variant is originally not signed, there is no zipAlign task.
        // This will update the output.getOutputFile() result to match the output of this.
        Task zipAlignTask = output.createZipAlignTask("zipAlign${output.name.capitalize()}",
                signTask.outputFile,
                project.file("$project.buildDir/outputs/apk/${project.archivesBaseName}-${output.baseName}.apk"))

        // have to make it depend on the signing task. All other dependencies have been setup automatically.
        zipAlignTask.dependsOn signTask
    } else {
        // reset the output of the output object.
        output.setOutputFile(signTask.outputFile)

        output.assemble.dependsOn signTask
    }
}

// record in the model that the variant outputs are signed.
// This lets Studio knows that the apks can be deployed to a device
variant.outputsAreSigned = true