How to add a Gradle task to an Android build

Question

I would like to add a gradle task to my Android build under Android Studio. Various on-line documentation shows clearly how to create a task, but not where to place it in a build.gradle file and which one of them.

A simple, complete example would be perfect.

BTW, I'd like to add a pre-build task to prepare some data, and maybe a post-build task to do some verification/validation.

Answer 1

By trial-and-error and input from Martin Zeitler, I successfuly added pre- and post-build tasks to my build.gradle (app module) as shown below:

This works perfectly.

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    buildToolsVersion "27.0.3"

    defaultConfig {
        applicationId "MyPackage"
        minSdkVersion 11
        targetSdkVersion 26
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }

    dependencies {
      // My libraries here
    }

    // MY PREBUILD TASK
    task PreBuild {
        println "MY PRE-BUILD TASK"
    }

    // MY POSTBUILD TASK
    gradle.buildFinished {
        println "MY POST_BUILD TASK"
    }
}