ViewModel object creation - use Dagger 2 about androidviewmodel

[FrantisekGazo]

@dozd You can also try Blade mvp module - it allows you to inject Presenters via Dagger2.

[dominikmicuta]

@dozd what about change of dependencies in component? If you inject them to ViewModel during creation through constructor, they can be no longer valid when activity subcomponent is recreated.
You load ViewModel with old dependencies from previous Subcomponent.
What about creating ViewModel without dependencies and reinject it when he is loaded from ViewModelProvider?

[dozd]

@micutad I can't imagine that dependencies have "shorter life" than ViewModel. One ViewModel cannot be shared through various Subcomponents as it's bound to the specific fragment that is in specific subcomponent.

Creating class without dependencies and injecting them during life-time of the class is anti-pattern in terms of mutability of the class. Dependency injection is about creating class with their dependencies easily not about managing them during the time of the class.

[dominikmicuta]

@dozd
If you have activity subcomponent than this subcomponent is recreated on config change because old activity is destroyed with current subcomponent, and new activity is created with new subcomponent.

If ViewModel is injected with this subcomponent and saved on config change then all dependencies are invalid after loading retained ViewModel because new activity have new subcomponent with new dependencies.

Not sure if Im explaining this clearly but in my case I have dependencies in ViewModel that are from Activity subcomponent and not from Application component.

[dozd]

How's your ViewModel living longer than activity? That sounds weird.

[dominikmicuta]

isnt it the one of main purpouses of this library? saving ViewModel during recreation?

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On Fri, Feb 3, 2017, 10:47 dozd ***@***.***> wrote: How's your ViewModel living longer than activity? That sounds weird. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#17 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ARhKA-EL9CjeC_lE4AboxOQCEfRATVMlks5rYvfCgaJpZM4JJhO0> .

[dozd]

But for one fragment. And fragment does not live longer than activity as well.

[dominikmicuta]

it saves ViewModels for all fragments inside activity. than activity is recreated and also fragments are recreated and saved ViewModels are delivered to fragments. new Activity subcomponent is created and its dependencies are different that dependencies in saved ViewModel.

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On Fri, Feb 3, 2017, 11:20 dozd ***@***.***> wrote: But for one fragment. And fragment does not live longer than activity as well. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#17 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ARhKA_2Ph8rJ0QIGEjK2zfQfdMfWbjfUks5rYv9SgaJpZM4JJhO0> .