Gradle templates

Gradle templates configure how to build an Android application using GradleAn Android build system that automates several build processes. This automation means that many common build errors are less likely to occur. More info
See in Glossary. Each Gradle template represents a single Gradle project. Gradle projects can include, and depend on, other Gradle projects.

Gradle template files

A Gradle template consists of the following files:

Using a custom Gradle template

There are two .gradle files that control the Gradle build process for the unityLibrary module:

• build.gradle: Specifies build instructions.
• settings.gradle: Contains the names of modules that the Gradle build system should include when it builds the project.project components that the instructions in the build.gradle file use in the build process.

build.gradle

The build.gradle file contains template variables that specify build instructions.

By default, Unity uses the mainTemplate.gradle file from the Unity install directory to create the build.gradle file for the unityLibrary module. To create your own mainTemplate.gradle file:

1. Open the Project Settings window (menu: Edit > Project Settings).
2. Select the Player tab then open Android Player Settings:
   
3. In the Publishing Settings section, enable Custom Main Gradle Template. This creates a Gradle template file called mainTemplate.gradle and displays the path to the file. Unity now uses this mainTemplate.gradle file to create the build.gradle file. For a list of template variables and a description of what each does, see Template variables.

Template variables

The mainTemplate.gradle file can contain the following variables:

settings.gradle

The settings.gradle file contains project components used in the build process.

By default, Unity uses the settingsTemplate.gradle file from the Unity install directory to create the settings.gradle file for your build. To create your own settingsTemplate.gradle file, create a settingsTemplate.gradle file in your project’s Assets/Plugins/Android/ folder. This overrides the default template.

If you create a custom settings.gradle file, be aware of the following:

• Unity creates the launcher and unityLibrary components by default and you must include them in your settingsTemplate.gradle file. To do this, add include ':launcher', ':unityLibrary' as an entry to your settingsTemplate.gradle.
• If you use Android Library plug-ins, Unity includes them in the final settings.gradle file by replacing the **INCLUDES** entry. This means you must add **INCLUDES** as an entry to your settingsTemplate.gradle.

Modifying the exported Gradle project using C#

To modify the Gradle project after Unity assembles it, create a class that inherits from IPostGenerateGradleAndroidProject and override the OnPostGenerateGradleAndroidProject function. This function receives the path to the unityLibrary module as a parameter and you can use it to reach the application’s manifest and resources through C# scripting.

Warning: Unity now uses an incremental build pipeline which means Unity reuses the same Gradle project for consecutive builds. This means that any modifications you do using this API accumulate since Unity no longer creates a new Gradle project for every build. For example, if you use this API to add an additional file to the Gradle project, the first build works as expected, but during the second build the file already exists. A second example is if you use this API to add a permission to a particular file. Each successive build adds another entry for the permission. It is crucial to make sure that modifications you want to make aren’t already present in the build.