Forgetting Android
Jorge J. Barroso!
Tech Lead Android Core!
jbarroso@tuenti.com!
@flipper83

Any fool can write code that a computer can understand. Good
programmers write code that humans can understand.!
Martin Fowler

1 Solid

Single responsibility principle
Open/closed principle
Liskov substitution principle
Interface segregation principle
Dependency inversion principle

Clean Architecture2

A good architecture allows you to defer framework decisions. A
good architecture allows frameworks to act as plugins to the app.!
Robert Martin
“The database is a detail, a hardware detail. We would not
use one at all if all our data could fit in memory for ever”

UI
External!
Interfaces
Db
Push
Network
Storage
Interfaces
Interfaces
Business
Model
Interactors
Interactors

UI!
Layer
UI!
Layer
UI!
Data Model
Data
Mapper
Boundary
Interactor
Bussines!
Data Model
Data!
Storage
Test!
Storage
Data
Mapper
Data
Mapper
Storage!
Data Model
Test!
Data Model

FeedViewModel
FeedBoundary
FeedListFragment
FeedProvider
GetFeed GetFeedImp
List<Hipster>
User!
DataSource!
Net
UserDataSourceLikeDataSource
Like!
DataSource!
Parse
API
UserApi
API
Retrofit!
api
Parse!
api

Conclusion3
http://www.flickr.com/photos/inf3ktion/

Good Layer Responsabilites

Easy to test and mock

Easy to add or modify code

Easy to hide implementations

Easy to find smells

Async code

Duplicate data model

Change your mind

Not silver bullets

http://jobs.tuenti.com!
jbarroso@tuenti.com!
@flipper83