Model View Presenter(MVP) is similar to other structural patterns for implementing separation of concerns, such as Model-View-Controller and Model-View-ViewModel. In MVP on Android, your activities and fragments typically act as the view objects by implementing a view interface, and handle interaction of the app with the user.
The view passes on user actions to the presenter, which handles the business logic and interaction with data repositories, such as a server API or database. The model layer consists of the objects that make up the content of the app.
This is the part 4 of the article series. In part 3 we learnt what a
Component is, how it wires with the
Module. We also implemented the DemoApplication Activity lifecycle & the respective layout.
In this article we would learn how
DaggerApplicationComponent generates the DAG(Directed Acyclic Graph) when we provide the
ApplicationModule class to it. Further, we would learn how
@inject is used to get the object instance to finish our learning about Dagger2. Let's get started!
This is the part 3 of the article series. In part 2 we implemented the
SharedPrefsHelper and we modeled the class so that we can retrieve the value from the database.
We will learn next what is a
Component, how we can create a
Component & how it wire itself in the DemoApplication to generate the dependent acyclic grap of objects.
Using Dependency Injection in Android.
This is the part 2 of the article series. In part 1 we understood the need and advantages of dependency injection. We also got an overview of Dagger2. In this part, we will focus on implementing the DI using Dagger2 in an android app.For the sake of this tutorial, we will break the process in steps and analyze each step one by one. Remember Dagger2 requires a concentrated approach. So actively follow the below tutorial, asking a lot of questions.
Posted on 29th Oct 2017 00:38:52 in Java
In the Java world, there are a number of frameworks that have been created to simplify the application of dependency injection. The frameworks remove a lot of the boilerplate code that can occur, and also provide a systematic way to apply dependency injection across a software system.
While a fantastic accomplishment, the initial Dagger framework had a few downsides. For example, performance issues due to runtime reflection and difficulty working with ProGuard.
As a result, the updated Dagger 2 framework was born, which produces simpler generated code and solves the performance issues by having injection occur at compile time.
The name “Dagger” is inspired in part by the nature of dependencies in software development. The web of dependencies that occur between objects such as
C, …, create a structure called a Directed Acyclic Graph. Dagger and Dagger 2 are used to simplify the creation of such graphs in your Java and Android projects.
For the remainder of the tutorial, the term Dagger will refer to Dagger 2.