Is it possible to inject presenter using Dagger instead of @InjectPresenter?

[MasoudFallahpour]

Is it possible to inject the presenter using Dagger and @Inject instead of provided @InjectPresenter? From my experiments that's not possible.

[senneco]

@MasoodFallahpoor yes, it's. But then you should manually attach/detach view from prersenter and manage lifecycle of presenters.

Also, you can use both Moxy and Dagger =) Then you should write some like this:

@Inject
Presenter daggerPresenter;

@InjectPresenter
Presenter moxyPresenter;

@ProvidePresenter
Presenter providePresenter() {
    return daggerPresetner;
}

@Override
public void onCreate(Bundle saveState) {
    Component.get().inject(this);
    super.onCreate();
    ....

Or

@Inject
@InjectPresenter
Presenter presenter;

@ProvidePresenter
Presenter providePresenter() {
    return presetner;
}

@Override
public void onCreate(Bundle saveState) {
    Component.get().inject(this);
    super.onCreate();
    ....

[MasoudFallahpour]

Thanks for your super quick response!

[alaershov]

@senneco In your second code sample, won't the presenter be injected by Dagger every time you call Component.get().inject(this); in onCreate()?

[A-Zaiats]

@alaershov you can move Component.get().inject(this) into the providePresenter() method.

[alaershov]

@A-Zaiats But then I won't be able to inject other dependencies into my activity, if it depends on something besides presenter.

Maybe it would be better to do this:

@InjectPresenter
MyPresenter mPresenter;

@ProvidePresenter
MyPresenter providePresenter() {
    return mComponent.providePresenter();
}

@Override
public void onCreate(Bundle saveState) {
    mComponent = getComponent();
    mComponent.inject(this);
    super.onCreate();
    ...

It allows me to inject other dependencies to the activity, and does not reinject presenter on each recreate.

[bejibx]

I'm doing it like this:

@InjectPresenter
MyPresenter mPresenter;

@Inject
Provider<MyPresenter> presenterProvider;

@ProvidePresenter
MyPresenter providePresenter() {
    return presenterProvider.get();
}

@Override
public void onCreate(Bundle saveState) {
    mComponent = getComponent();
    mComponent.inject(this);
    super.onCreate();
    ...

[matzuk]

@alaershov about this example:

@Inject
@InjectPresenter
Presenter presenter;

@ProvidePresenter
Presenter providePresenter() {
    return presetner;
}

@Override
public void onCreate(Bundle saveState) {
    Component.get().inject(this);
    super.onCreate();
    ....

If your Presenter was provided from Dagger with concrete Scope than there is only one instance of your Presenter and there is no cause for concern I think.

[alaershov]

@matzuk That's true, it's only a matter of taste. I find this example a bit confusing for beginners, but it's a nice puzzle for those who want to thoroughly understand the order of injections in Moxy+DI combo, as well as the essence of DI scopes.

[xanderblinov]

@alaershov with another DI framevork it looks more sweetly:

    @InjectPresenter
    internal lateinit var presenter: ProfilePresenter

    @ProvidePresenter
    fun providePresenter(): ProfilePresenter {
        return Toothpick.openScopes(DI.USER_SCOPE).getInstance(ProfilePresenter::class.java)
    }

[alaershov]

@xanderblinov Toothpick is definitely more user-friendly than Dagger :) However, your example does not inject the Activity/Fragment itself, and the more complete example could look like this:

private val scope: Scope by lazy { Toothpick.openScopes(DI.USER_SCOPE) }

@Inject
internal lateinit var someStuff: SomeStuff

@InjectPresenter
internal lateinit var presenter: ProfilePresenter

@ProvidePresenter
fun providePresenter(): ProfilePresenter {
    return scope.getInstance(ProfilePresenter::class.java)
}

@Override
fun onCreate(...) {
    Toothpick.inject(this, scope);
    super.onCreate();
}

[matzuk]

@alaershov @xanderblinov
Oh God, it's amazing!

[Yazon2006]

Possible way of injection with Dagger (where Lazy is from dagger package import dagger.Lazy). Initialization of presenter happening only when providePresenter() calls.

	@Inject
	lateinit var daggerPresenter: Lazy<SomePresenter>
	
	@InjectPresenter
	lateinit var presenter: SomePresenter
	
	@ProvidePresenter()
	fun providePresenter(): SomePresenter = daggerPresenter.get()

[danilNikolaenko1990]

@MasoodFallahpoor yes, it's. But then you should manually attach/detach view from prersenter and manage lifecycle of presenters.

Also, you can use both Moxy and Dagger =) Then you should write some like this:

@Inject
Presenter daggerPresenter;

@InjectPresenter
Presenter moxyPresenter;

@ProvidePresenter
Presenter providePresenter() {
    return daggerPresetner;
}

@Override
public void onCreate(Bundle saveState) {
    Component.get().inject(this);
    super.onCreate();
    ....

Or

@Inject
@InjectPresenter
Presenter presenter;

@ProvidePresenter
Presenter providePresenter() {
    return presetner;
}

@Override
public void onCreate(Bundle saveState) {
    Component.get().inject(this);
    super.onCreate();
    ....

I'm doing it like this:

@InjectPresenter
MyPresenter mPresenter;

@Inject
Provider<MyPresenter> presenterProvider;

@ProvidePresenter
MyPresenter providePresenter() {
    return presenterProvider.get();
}

@Override
public void onCreate(Bundle saveState) {
    mComponent = getComponent();
    mComponent.inject(this);
    super.onCreate();
    ...

in my case it doesn't worked out. I see in debugger, that dagger presenter was injected, but when calls providePresenter daggerPresetner is null. It seems like ProvidePresenter fulfills BEFORE @Inject fulfils. What could be cause of problem? thanks. Sorry for my english

[alaershov]

@danilNikolaenko1990 Hi there! Moxy has migrated to a new repository. This repository is deprecated and no longer maintained. You're welcome to open a new issue in the new repository, but if you only need some advice - welcome to our Telegram group! Feel free to ask any questions about Moxy there.

[danilNikolaenko1990]

@danilNikolaenko1990 Hi there! Moxy has migrated to a new repository. This repository is deprecated and no longer maintained. You're welcome to open a new issue in the new repository, but if you only need some advice - welcome to our Telegram group! Feel free to ask any questions about Moxy there.

thanks!