How to implement sharedPreferences with dagger 2 in presenter layer without context?

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Closed. This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 3 years ago. Improve this question How to implement sharedpreferences with dagger and MVP, most of the tutorials are writing the sharedpreferences in the Activity or providing the context to presenter. what i need is to see example: what should i write into my presenter to get the sharedPreference without using the Context. how the module will look like. Do i need to call the Component from Application or with every activity to provide the context. ===Update=== As PPartisan mentioned in his answer that i should't include the sharedPreference in the Presenter. So how can i abstract the SharedPreferences behind an API ===Update 2=== Thanks for your answer PPartisan it really worked very good, could you please check my code if its perfectly written, or need any adjustments. MainActivity @Inject MainPresenter presenter; AppComponent component; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); component = DaggerAppComponent .builder() .contextModule(new ContextModule(this)) .build(); component.inject(this); } AppModule @Module public abstract class AppModule { @Binds abstract Repository bindRepository(SharedPrefsRepository prefs); @Binds abstract MainPresenterListener listener(MainPresenterListener mListener); @Provides static SharedPreferences prefs(Context context) { return PreferenceManager.getDefaultSharedPreferences(context); } } ContextModule @Module public class ContextModule { private Context context; public ContextModule(Context context) { this.context = context; } @Provides Context getContext() { return context; } } AppComponent @Component (modules = {AppModule.class, ContextModule.class}) public interface AppComponent { void inject(MainActivity activity); } JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

In its simplest form (and assuming Context is already part of your dependency graph), then in your module: @Provides static SharedPreferences prefs(Context context) { return PreferenceManager.getDefaultSharedPreferences(context); } And in your Presenter: class Presenter { private final SharedPreferences prefs; @Inject Presenter(SharedPreferences prefs) { this.prefs = prefs; } } There's more you can do with this however. For instance, you can scope the Presenter to the lifecycle of the View (i.e. an Activity or Fragment). Also, a "Presenter" in its purest form should know nothing of Android components, so you may want to abstract the SharedPreferences behind an API of your own. Edit: Here's an example of how you might abstract your data persistence so you Presenter can remain unaware of Android components: Create a suitable interface (this just persists and returns Strings, so modify it accordingly): interface Repository { String read(); void write(String value); } Create an instance of this interface that delegates to SharedPreferences: class SharedPrefsRespository implements Repository { private static final String KEY = "a_key"; private final SharedPreferences prefs; @Inject SharedPrefsRepository(SharedPreferences prefs) { this.prefs = prefs; } @Override String read() { return prefs.getString(KEY, ""); } @Override void write(String value) { prefs.edit() .putString(KEY, value == null ? "" : value) .apply(); } } Tell Dagger that this implementation of Repository is the one you want to use by adding the following to your module (ensure your module is abstract): @Binds abstract Repository repository(SharedPrefsRepository prefs); In your Presenter, inject Repository rather than SharedPreferences: class Presenter { private final Repository repo; private View view; @Inject Presenter(Repository repo) { this.repo = repo; } void attach(View view) { this.view = view; showUserName(); } //Example of how you might use this repo on something you want to persist //Imagine a user has entered their username and clicked save... void onSaveUserName(String username) { repo.write(username); } private void showUserName() { view.showUsername(repo.read()); } }