Android Architecture Blueprints

The Android framework offers a lot of flexibility when it comes to defining how to organize and architect an Android app. This freedom, whilst very valuable, can also result in apps with large classes, inconsistent naming and architectures (or lack of) that can make testing, maintaining and extending difficult.

Android Architecture Blueprints is meant to demonstrate possible ways to help with these common problems. In this project we offer the same application implemented using different architectural concepts and tools.

You can use these samples as a reference or as a starting point for creating your own apps. The focus here is on code structure, architecture, testing and maintainability. However, bear in mind that there are many ways to build apps with these architectures and tools, depending on your priorities, so these shouldn't be considered canonical examples. The UI is deliberately kept simple.

Samples

All projects are released in their own branch. Check each project's README for more information.

Stable samples

Project	Description
todo-mvp	Basic Model-View-Presenter architecture
todo-mvp-loaders	Based on todo-mvp, fetches data using Loaders
todo-databinding	Based on todo-mvp, uses the Data Binding Library
todo-mvp-clean	Based on todo-mvp, uses concepts from Clean Architecture
todo-mvp-dagger	Based on todo-mvp, uses Dagger2 for Dependency Injection
todo-mvp-contentproviders	Based on todo-mvp-loaders, fetches data using Loaders and
todo-mvp-rxjava	Based on todo-mvp, uses RxJava for concurrency and data layer abstraction

Samples in progress

Project	Description
dev-todo-mvp-tablet	Based on todo-mvp, adds a master/detail view for tablets
dev-todo-mvvm-databinding	Based on todo-databinding, uses Model-View-ViewModel architecture

Also, see "New sample" issues for planned samples.

External samples

External samples are variants that may not be in sync with the rest of the branches.

Project	Description
todo-mvp-fragmentless	Based on todo-mvp, uses Android views instead of Fragments
todo-mvp-conductor	Based on todo-mvp, uses the Conductor framework to refactor to a single Activity architecture

Why a to-do application?

The aim of the app is to be simple enough that it's understood quickly, but complex enough to showcase difficult design decisions and testing scenarios. Check out the app's specification.

Also, a similar project exists to compare JavaScript frameworks, called TodoMVC.

Which sample should I choose for my app?

That's for you to decide: each sample has a README where you'll find metrics and subjective assessments. Your mileage may vary depending on the size of the app, the size and experience of your team, the amount of maintenance that you foresee, whether you need a tablet layout or support multiple platforms, how compact you like your codebase, etc.

See also:

• Samples at a glance
• How to compare samples

Opening a sample in Android Studio

First check out one of the sample branches (master won't compile), and then choose to open the todoapp/ directory. Example:

• git clone git@github.com:googlesamples/android-architecture.git
• git checkout todo-mvp (or replace todo-mvp with the project you want to check out)
• In Android Studio open the todoapp/ directory.

Who is behind this project?

This project is built by the community and curated by Google and core maintainers.

External contributors

David González - Core developer (Content Providers sample)

Karumi - Developers (MVP Clean architecture sample)

Natalie Masse - Core developer

Erik Hellman - Developer (MVP RxJava sample)

Saúl Molinero - Developer (MVP Dagger sample)

Florina Muntenescu - Developer (MVP RxJava sample)

Googlers

Jose Alcérreca - Lead/Core developer

Stephan Linzner - Core developer

Mustafa Kurtuldu - UX/design

Want to be part of it? Read how to become a contributor and the contributor's guide