Compile, Provided, APK - Android dependency scope

• provided - compile-time only dependency
• package - package-time only dependency
• compile - compile-time and package-time dependency

provided is commonly used for annotation processing based libraries. Usually these libraries are separated in two artifacts - "annotation" and "compiler". "compiler" is provided dependency because you do not need to use it in application, only for compilation; and "annotation" is compile dependency - it is used in application code and therefore compiles. Or generated code may require additional dependencies while your application may not. E.g. dagger dependencies configuration:

compile 'com.squareup.dagger:dagger:1.2.2'provided 'com.squareup.dagger:dagger-compiler:1.2.2'

These properties come from maven scopes.

They simply indicate how to treat particular dependencies during each step of build process.

1. compile - a default approach, it simply means that all dependencies should be available at compile-time. Compile dependencies are available in all classpaths of a project. Furthermore, those dependencies are propagated to dependent projects. A compile-time dependency is generally required at runtime.

2. package - declares additional configuration for building an application. You can list plugins that add additional functionality to the build process.

3. provided - it means that runtime environment has these dependencies included. For example, when you look into android.jar library internals you will see java.lang.RuntimeException: Stub! in every method body.

   That has some consequences:

   • You can develop Android applications locally, without having complete Android environment.
   • Your APK you must run it on an android device or an emulator because they provide implementation of these methods.
   • Your apps that reference the SDK classes will build properly, because the jar provides the class metadata.
   • Unless you use some library that provides artifacts (e.g. Robolectric), you have to run tests on your emulator/device.

provided and package cannot be used with Android Libraries, and will generate an error.

Here is how sourceSet looks like:

More info about build system: https://www.youtube.com/watch?v=LCJAgPkpmR0

An awesome article about Gradle: http://www.sinking.in/blog/provided-scope-in-gradle/

Xavier talks here about the APK scope.

in the Android plugin, The equivalent (sort of) of runtime is called apk. You can do

dependencies { apk files('libs/foo.jar') }

and it'll only get packaged but won't be on the compile classpath.