dagger-2

I saw the following example on the Dagger 2 website : class Thermosiphon implements Pump { private final Heater heater; @Inject Thermosiphon(Heater heater) { this.heater = heater; } ... } and the documentation: When a new instance is requested, Dagger will obtain the required parameters values and invoke this constructor. When I write a Module to provide a Thermosiphon like @Module public class ThermosiphonModule { @Provides @Singleton Thermosiphon provideThermosiphon() { return new Thermosiphon(???); } } the Thermosiphon constructor still requires a Heater as an argument, rendering the whole

Say I have a class Util that takes in a object - an instance of class Validator . Since I want to avoid instantiating the Validator class within Util, I pass it in via a constructor: public class Util { @Inject public Util(Validator validator) { } } I have a module that provides the Validator instance: @Provides @Singleton Validator provideValidator() { return Validator.getInstance(); } and an instance of the Util class: @Provides Util provideUtil(Validator validator) { return new Util(validator); } I have a component wired up that would give me an instance of Util: Util getUtil() so within my

Do you have a specific package where you put all the Dagger related classes? Or do you put them next to the relevant class they inject, e.g. if you have an MainActivityModule and MainActivityComponent , you put them in the same package as your MainActivity . Also, I've seen quite a few people defining components as inner classes, e.g. an ApplicationComponent that is defined inside the Application class. Do you think this is a good practice? EDIT: Let me start out with the fact that this is close to the truth here, but this is an antipattern as described by Martin Fowler's Data Domain

I am using Dagger 2 and have it working however I now need access to the Android Application Context. Its not clear to me how to inject and get access to the context. I have tried to do this as follows: @Module public class MainActivityModule { private final Context context; MainActivityModule(Context context) { this.context = context; } @Provides @Singleton Context provideContext() { return context; } However this results in the following exception: java.lang.RuntimeException: Unable to create application : java.lang.IllegalStateException: mainActivityModule must be set If I inspect the

PROBLEM I need to call API from domains entered by USER and I need to edit my Retrofit singleton before the call accordingly to the inserted data. Is there a way to "reset" my singleton, forcing it to recreate? or Is there a way to update my baseUrl with my data (maybe in Interceptor?) just before call? CODE Singletons @Provides @Singleton Retrofit provideRetrofit(SharedPreferences prefs) { String apiUrl = "https://%1s%2s"; apiUrl = String.format(apiUrl, prefs.getString(ACCOUNT_SUBDOMAIN, null), prefs.getString(ACCOUNT_DOMAIN, null)); OkHttpClient httpClient = new OkHttpClient.Builder()

From the User's Guide : Sometimes you want to limit the number of times an @Inject-constructed class is instantiated or a @Provides method is called, but you don’t need to guarantee that the exact same instance is used during the lifetime of any particular component or subcomponent. Why would I use that instead of @Singleton ? Use @Singleton if you rely on singleton behavior and guarantees. Use @Reusable if an object would only be a @Singleton for performance reasons. @Reusable bindings have much more in common with unscoped bindings than @Singleton bindings: You're telling Dagger that you'd