Change ContextSingleton retention policy to RUNTIME

[zawadz88]

Hi,
First of all thanks for the great library!
Recently, I tried updating toothpick from 1.0.3 to 1.0.5 in my Android project and got:
Error:Scope Annotation toothpick.smoothie.annotations.ContextSingleton does not have RUNTIME retention policy. during compilation.
I checked and ContextSingleton from smoothie has runtime policy CLASS currently unlike e.g. Singleton from javax.inject or the custom scope in smoothie-sample which probably causes this error. This is probably due to the changes in #191

Could you help please?

[dlemures]

Hi @zawadz88 ,

Thanks for the issue.

This class was meant to be there just as an example. However, the javadoc is not really clear and probably the class is not useful either.

Therefore, we will deprecate the class, change the retention and update the javadoc.
The class will be removed in a later release.

If you are using context singletons, please create the annotation yourself and bind it to the right scopes:
https://github.com/stephanenicolas/toothpick/wiki/Scope-Annotations#binding-a-scope-to-a-scope-annotation

[stephanenicolas]

I would add that ContextSingleton was really a RoboGuice thing. It looked really cool at that time as you could quickly inject a context. At Groupon, we used a TP ContextSingleton for our migration from RG to TP.

But, later, we just removed it. The issue is that when you @Inject Context, then you just don't know exactly which context you are injecting : an activity or the app context ?? And one can create a leak, not the other one, simply depending on where you inject your entity.

So, definitely ContextSingleton is more a simple example of a custom annotation but it should not be used in a production app. At Groupon, we use instead Singleton, ActivityScope, ServiceScope, and we never inject a context, always either the Application or an Activity or a Service, so that we have full control over what is injected. And we use the scope verification mechanism of TP to be sure we don't leak an activity or a service.

[zawadz88]

Thanks for the clarification and sorry for the misclick ;)

[HugoGresse]

I was searching how to inject the Application in a @Singleton is there any example on the documentation/demo?
I also don't find any documentation about the SmoothieApplicationmodule. I'm just a beginner with DI :/

[stephanenicolas]

If you install the smoothie application module in your app scope, then you can simply use @Inject Application app in this scope or any sub scope.

All the docs of TP is in the wiki in the repo... @HugoGresse

[dlemures]

@HugoGresse were you able to do it?

[HugoGresse]

yep, that was fine. I've still some issue where the @Inject is done after constructor call which conduce me to delay some action. For example here. I've probably made something wrong but I am inject the scope on the class AFTER is instantation that maybe be this.

[stephanenicolas]

@HugoGresse there are 2 things you can do with TP, and I believe it's the same with dagger / Roboguice:

• use a constructor with @Inject annotation, then all arguments will be created by TP (it needs to have a provider / or a binding or the classes to be annotated properly).

class Foo {
  Bar bar;

  @Inject
  public Foo(Bar bar) {
     bar.bar(); // <-- would work as long as TP knows how to create the instance of Bar 
  }

• use a @Inject annnotated method. These methods are executed after fields are initialized.

class Foo {
  @Inject Bar bar;

  @Inject
  public Foo() {
     bar.bar(); // <-- would fail because members are not initialized yet, see the factory code.
  }

 @Inject
 void init() {
     bar.bar(); // <-- would work
  }
}

[stephanenicolas]

Release 1.0.8 will solve this issue.