Android architectural components
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The document discusses Android architecture components, outlining their purpose and differences from design, popular patterns like MVC, MVP, MVVM, and VIPER, and Google's guidelines for efficient application architecture. It emphasizes the importance of lifecycle management, with components like ViewModel and LiveData for improved UI data management and responsiveness to configuration changes. Additionally, the Room persistence library is introduced as a means to manage app data effectively, mitigating boilerplate code and enhancing maintainability.
Android architectural components
- 1. Android Architecture Components Muhammad Ali Software Architect VentureDive
- 2. Architecture • What is architecture • Why is architecture required? • How architecture is different from design? • Popular architectural patterns • MVC • MVP • MVVM • VIPER
- 3. Android Architecture Components • Google’s official guidelines to architect your Android applications • Reduce boilerplate • Separation of concerns • Testability • Maintainability • Ease of Implementation
- 4. Android Architecture Components • Activities/Fragments • Represents View Layer • Handle UI events • ViewModel • Observes View lifecycle events • Bring data from Repository and update Views • Uses LiveData to observe changes to the data in repository • Repository • Brings data from sqlite using Room • Brings data from services
- 5. Lifecycle • Problems without lifecycle • Sometimes services starts after activity stops, for example a long running code is being executed in onStart and after that a particular component/service is started • In that case component/service is alive when it shouldn’t be • Lifecycle solves this problem with events and states • Component can be made lifecycle aware with the help of following • LifeCycleObserver • LifeCycleOwner
- 6. ViewModel • View Model is designed to store and manage UI related data in lifecycle conscious way • Idea is same, keep Views free from fetching and managing any data • ViewModel survives configuration changes such as screen resolutions • ViewModel must not reference a view • If you need context in a ViewModel, use AndroidViewModel class
- 7. ViewModel
- 8. LiveData • LiveData is an observable data holder class • LiveData is lifecycle aware • Lifecycle awareness ensures LiveData only update app components observers that are in active lifecycle state • Ensure UI is consistent with data • Sharing resources • Enduring configuration changes
- 9. Room • Room persistence library provides an abstraction layer over sqlite • It helps you create a cache of your app’s data on a device running your app • This cache acts as a system of record or single source of truth • Provides an ORM capability with annotations and compile time code generation • Remove boilerplate code for creating DAO