AndroidX is a fairly large project with 300+ modules which makes it a very resource heavy project for local development.
Playground setup allows sub projects to have an additional settings.gradle file that can be run independent of the main project. It also allows using external resources for artifacts such that just checking out the AndroidX git repository is enough without the prebuilt repositories that are needed by the main AndroidX project.
These project setups are only meant to be used for local development and all CI tasks run using the root AndroidX project.
A playground project needs a
settings.gradle file that includes the
playground-common/playground-plugin build and applies the
playground plugin provides functionality allowing the playground project to be executed independently of the main AndroidX build, and to pull select projects from AndroidX.
To share as much common configuration as possible, it is also recommended to symlink some common files like
To do that, execute “setup-playground.sh” command in your playground directory.
cd room; ../playground-common/setup-playground.sh
This script will create symbolic links for
.idea files that are committed to the git repository. It also force adds the
.idea files to the git repository because by default any nested .idea folder is ignored from git.
playground plugin sets a pre-defined build file (
playground-build.gradle) for the root project and also provides a
playground extension for
settings.gradle with useful configuration methods.
settings.gradle file should first call
setupPlayground("..") on the
playground extension to establish the main configuration, providing the relative path of the playground project to the main AndroidX project.
setupPlayground, it can either include projects via
includeProject method or filter projects from the main AndroidX settings gradle file using the
gradle.properties file shows up under a sub project, main AndroidX build ends up reading it. For this reason, we can only keep a minimal
gradle.properties file in these sub modules that also support playground setup.
We cannot avoid creating
gradle.properties as certain properties (e.g.
useAndroidX) are read at configuration time and we cannot set it dynamically.
Properties that will be set dynamically are kept in
playground.properties file while shared properties are kept in
androidx-shared.properties file. The dynamic properties are read in the
playground plugin and set on each project.
There is a
VerifyPlaygroundGradleConfigurationTask task that validates the contents of
androidx-shared.properties file as part of the main AndroidX build.
Even though sub-projects usually declare exact coordinates for their dependencies, for tests, it is a common practice to declare
project dependencies. To avoid needing to include all of those projects to make the build file work,
AndroidXPlaygroundRootPlugin adds a
projectOrArtifact method to each sub project. This function can be used instead of
project to declare optional project dependencies. This function will return the
project if it exists or default to its latest artifact if it doesn't.
Note that range artifacts are not allowed in the main AndroidX build so when the sub project is opened as part of the main AndroidX build,
projectOrArtifact always resolves to the
project. In playground projects, it always resolves to the latest
SNAPSHOT artifact that is included in the playground build.