The Anvil sample consists of 3 modules:

• :sample-anvil: The actual application that demonstrates an example features.
• :sample-anvilcodegen: The anvil-compiler code generator that allows @ContributesViewModel to setup all of the wiring necessary for constructor dependency injection.
• :sample-anvilannotations: Shared annotations between the sample and codegen.

The Anvil sample demonstrates how to setup a @ContributesViewModel annotation that allows you to do constructor injection from Dagger without any additional wiring such as the creation of a Dagger module. The setup requires a bit of infrastructure which is all included in these three modules. However, once it is set up, it dramatically simplifies the usage of ViewModels and Dagger.

A good starting point is ExampleFeatureFragment. ExampleFeatureFragment and the other classes in that folder demonstrate:

• How to use @ContributesViewModel to do constructor injection.
• How to create feature/Fragment scoped Dagger Components that are supported by @ContributesViewModel.
• How to set up App/User/Feature Dagger component hierarchies that are commonly used in real world apps.