Model-View-Presenter Architecture Pattern in Android

These slides are from my session over "Model-View-Presenter Architecture Pattern in Android" at GDG DevFest 2016, Jaipur

Transcript

1. Model-View-Presenter Architecture Pattern in Android by Vishwajeet Srivastava
2. ➢ Android Developer by Profession Google Summer of Code Intern @Mifos Initiative Founder and Director @LNMHacks Coordinator @Cybros FOSS Guy About Me Twitter - @vishwajeets3 GitHub - @vjs3 Blog - vishwajeetsrivastava.com
3. How many Android Devs out there?
4. What is Architecture (of an app or software)? • Refers to the fundamental structures of a software system, the discipline of creating such structures, and the documentation of these structures. • Each structure comprises software elements, relations among them, and properties of both elements and relations. • In general terms, the architecture of a system is its 'skeleton'. It's the highest level of abstraction of a system.
5. Why should we care about Architecture? • Like any other complex structure, software must be built on a solid foundation. • Tools help you to develop software easily but they doesn’t replace need of careful design of software. • Architecture ensures quality. • Keeps developer focussed on the business logic of the application. • Helps writing a clean code. • High code coverage.
6. Android Dev without any architecture • Inherited Model-View Concept is present. • All the business logic is written in the View portion (i.e Activity, fragments etc). • Works fine with smaller apps with a small team or individual purpose. • Will have many problems if you want to have high code coverage for your source code. • What does it look like?
7. Diagrammatic view of an app without any architecture
8. That seems pretty clean to me? Basically everything is connected to everything else
9. Importance of MVP in android dev: • Clean code. • Business logic will not get cluttered with Android Code. • Easy testing (Mocking android elements get easier) • Happy life :D
10. Commonly used architectures in android • Model-View-Presenter (MVP) • Model-View-ViewModel (MVVM) • Uncle BoB’s Clean Architecture • And Many more
11. • You can use whatever seems best in your use case. • Every Architecture has its own pros and cons • Many people uses more than one architecture at a time • How is that possible? Which one should I choose?
12. Model-View-Presenter Architecture Pattern What is MVP? View is a layer that displays data and reacts to user actions. On Android, this could be an Activity, a Fragment, an android.view.View or a Dialog. Model is a data access layer such as database API or remote server API. Presenter is a layer that provides View with data from Model. Presenter also handles background tasks.
13. What MVP? Keep It Stupid Simple (KISS)
14. • Complex tasks are split into simpler tasks and are easier to solve. • Smaller objects, less bugs, easier to debug. • Testable
15. Shall we move to the real world? • Sample Codes • Apps using MVP? ◦ Ribot ◦ Mifos-Self-Service App ◦ Google Sample Apps
16. I understood what M and V, what the hell is P? • Presenter is the core of application • It contains our business logic • Should be written in a way that this logic can be used in another app • Presenter should do all the talking with Views as well as Model • View and Model Should only interact with each other via Presenter • Presenter should only send the data which is required by the View (nothing less or more).
17. Third Party Libraries commonly used with MVP • Dagger 2 (Injection) • Retrofit (generic) • RxJava (dicy :p)
18. Who has time for all this? It's all so complex so we shall use an MVP library! ………………..
19. - it's all talk until the code runs Shall we dive in? ~ Ward Cunningham
20. Some Awesome Resources to begin learning MVP • Google Sample Apps • Ribot Blog • Ribot Boiler Plate code
21. Thanks! Vishwajeet Srivastava (vjs3)
22. Bonus Slide: • Awesome Resources ◦ GitHub ◦ Android Developer’s channel ◦ Twitter ◦ And many more…….. • Good Practices