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dagger

mattinger

10/20/2022, 11:06 PM

I’m generally having issues with IntoMap as a whole. Even if i have a type defined

interface SomeTypeFactory: Function0<SomeType>

And use that instead, i get the same sort of error

10/20/2022, 11:07 PM

Yes the wildcards will cause issues.

10/20/2022, 11:07 PM

Dagger needs updated to use the declared type from the Kotlin metadata and not the bytecode type in general

10/20/2022, 11:08 PM

For normal types you can work around it with @JvmSuppressWildards. Don't think you can do anything with function types, but I haven't tried.

mattinger

10/20/2022, 11:12 PM

Thanks @jw I just tried that, and it seems to work for function types. I remember having to do this for @IntoSet before, but that was a while ago and forgot about it.

mattinger

10/20/2022, 11:13 PM

factories: Map<@JvmSuppressWildards Class<*>, @JvmSuppressWildards () -> SomeType>

mattinger

10/20/2022, 11:14 PM

My main use case for this is going to end up creating a ViewModel factory. I want to inject that into my activity to pass off to the higher level composables that need to create composable scoped view models. It definitely seems cleaner to me than injecting all the services i would need to create those view models and having to pass them down the line. This does have one limitation in that you can’t have one view model take another as a constructor argument, since you don’t have the ViewModelStoreOwner inside of the factory.

agrosner

10/21/2022, 2:15 AM

+ 1 that dagger should use the kotlin metadata declared type. Dagger needs work to support kotlin better on that front. Having to provide functions just to cast away their generics … 🙃

Sushobh

11/01/2022, 2:48 AM

I am working on a new app and I am planning to use dagger. I am specifically interested to know your thoughts on dagger components. 1. Should I create components based on the lifecycle of their use case. For example, a component for all objects when the user is logged in? I am confused about how to structure my components. 2. Where should components be stored? For example, for the user logged in component, where do I store the component? 3. How do I dispose of components? Is setting it to null enough? Online posts do not go into the details of how to structure components for large projects. So I am having a hard time, how many components to create and for what use cases. Please assist. If there is a better channel for this question let me know.

Sergio C.

11/01/2022, 11:11 PM

Hi, Any ideas on how to make this work? I need to observe the API URL change from shared preferences in the APIModule but Hilt doesn't like the idea of injecting constructor here... Modules that need to be instantiated by Hilt must have a visible, empty constructor.

@Module
@InstallIn(SingletonComponent::class)
class ApiModule @Inject constructor(
    localPrefs: SharedPreferences,
    app: Application,
) {

    init {
        localPrefs.registerOnSharedPreferenceChangeListener { prefs: SharedPreferences?, key: String? ->
            if (key == app.getString(R.string.pref_key_api_url)) {
                val newApiUrl = prefs?.getString(key, defaultApiUrl) ?: defaultApiUrl
                Logger.w("API URL CHANGED!!! $newApiUrl")
            }
        }
    }

}

Preetham Ivan Dsouza

11/07/2022, 12:35 PM

Hi, How can we update a singleton component if we have any param changes to be applied to any given @provides method using Hilt dependency injection? Since Singleton components are initialised initially itself and if we have to update any keys to the

certificatePinner

etc (if we are setting keys dynamically and not locally) how do we achieve the same with Hilt? Ref: Similar use case to this issue

Kshitij Patil

11/28/2022, 6:47 AM

I am currently writing a ksp processor which generates

FooImpl

for an interface

Foo

when annotated. Now I want dagger to know binding

Foo

with

FooImpl

from my generated code. Adding simple

@Inject

to the constructor of generated class doesn’t work, I guess because the code is not available at compile time. How can I achieve this?

Christoph Wiesner

12/14/2022, 7:12 AM

i have the problem of injecting different implementations of an interface depending on a config:

@Provides
fun provideManager(config, managerImplA, managerImplB): Manager {
	return if (config.shouldUseA) {
		managerImplA
	} else {
		managerImplB
	}
}

doing this means i have to instantiate both implementation but only one gets used in the end. problem is that all the dependencies of the implementation also will get wired up and kick off some processes that i do not want to be instantiated if that version is not gonna be used. is there a way to achieve this without having the instances already?

dimsuz

12/16/2022, 11:37 AM

Hi! If I have

interface A
interface B

class AB : A, B

And I want to have a single intance of

AB

provided as

and

separately:

@Provides fun providesA(): A
@Provides fun providesB(): B

How is this normally done in dagger? Do I do it like this:

@Provides fun providesAB(): AB
@Provides fun providesA(ab: AB): A = ab
@Provides fun providesB(ab: AB): B = ab

Feels like there could be a way to avoid manually writing such basic methods. Also don't like the fact that I have to provide

AB

too, although I'd prefer it to be an implemenation detail

nuhkoca

12/27/2022, 2:46 PM

Hello, I am trying to create a baseline profile for our project but

benchmark

module throws the exception below when executing

./gradlew connectedBenchmarkAndroidTest -Pandroid.testInstrumentationRunnerArguments.androidx.benchmark.enabledRules=BaselineProfile

task

symbol: class DeveloperSettingsModule
error: ComponentProcessingStep was unable to process 'path.to.package.core.di.ApplicationComponent' because '<error>' could not be resolved.

Can somebody please help me figure out what’s wrong with Dagger? I am confused.

mattinger

01/13/2023, 1:52 PM

Has anyone tried using dagger along with dynamic feature modules? Specifically anvil based dagger? Since the code is not actually downloaded with the app, i suspect it would be hard to include things in a feature module that contribute to the application/singleton scope. Also, i was under the impression that it was essentially a 2 way dependency, since you add the app project as a dependency in your gradle file. However, I seem to be unable to resolve classes from my app module.

01/13/2023, 1:54 PM

It will not work. You would have to use separate components for each feature and component dependencies to access things in the app module

01/13/2023, 1:54 PM

By definition your feature module scope is going to be smaller than your app/singleton scope because it can be loaded after the fact

mattinger

01/13/2023, 1:57 PM

That’s what i thought. I do have a feature module scope, but it contributes a factory creation function to the main AppScope, since the feature module scope is a sub component of the main one.

Emirhan Emmez

01/18/2023, 7:39 PM

Hi all, is there any good example repo for custom component usage in hilt? (especially for clean arch)

Susheel

01/19/2023, 5:24 PM

I have a class A that takes AppCompatActivity as a parameter. I want to be able to inject A using dagger. Is there a way to do that? (I'm also wondering if this is an anti-pattern)

Constantin Cezar Begu

01/23/2023, 3:30 PM

Hey I have a interesting problem. I am using hilt right now and found a limitation. Basically I want to. scope a class to a viewmodel store owner. Generally people would say to scope it to @ActivityRetainedScope but this is not good for my use case. Example: You have fragment 1 inside of fragment 2 and fragment 3 inside of fragment 2. fragment 1 and 3 can be destroyed at any point. the items created for fragment 1 (which is a viewmodel store owner) I don't want to share with fragment 2 or 3 (which are other viewmodel store owners). Injected items are shared for viewmodels (for fragment 1). Looks like @ActivityRetained scope does not do the trick since it would share for viewmodels but also for viewmodels used in fragment 1,2,3 (they use the same activity). @ViewmodelScoped scoped the item to a specific viewmodel (does not share with other viewmodels in fragment 1) Is there a elegant way to solve a problem like this?

Colton Idle

01/27/2023, 7:26 AM

I feel like I'm getting some conflicting info with hilt and assisted injection. I currently have this

class GetTeamsUseCase @Inject constructor(
  val apiService: ApiService, <---- provided by a @Provides method
  val accessToken: String <---- I'd like to "inject" this at runtime since I get it once I login
) {

Is this possible to do or do I need some other lirbary?

Philip Dukhov

02/06/2023, 2:53 PM

Hey, is there a way to know when object is no longer available so subscriptions, coroutine scope, etc, can be cancelled? Like with

ActivityScoped

, when activity is destroyed - in this particular case I could've get an activity with

ActivityContext

and listen to the lifecycle, but this won't work generally, e.g. with

ActivityRetainedScoped

. The only idea that come to my mind is using

finalize

but it seems to be a bad practice and doesn't seems to be reliable - as I understand there's no guarantee it'll be called on time. Usually

Closeable

is used in such situations, I've tried implementing it but Dagger doesn't seems to be checking it.

Colton Idle

02/08/2023, 7:20 PM

I've never used dagger/hilt in a multi-module setup. Lets say I have

app

gradle module which depends on

service

. And

service

inside has

SomeServiceClass

. Would

service

gradle module have a @Module and @Provides, providing the

SomeServiceClass

app

gradle module? Or is it more customary for the

service

gradle module to declare what it provides?

Colton Idle

02/09/2023, 10:20 PM

I did it! 😂

Colton Idle

02/10/2023, 4:15 PM

I have an

:app

module and then a

network

module. I want the network module to expose services like BooksService and LibraryService. Those two services require a OkHttpClient. I can also add a provider for the http client, but then okhttpClient provider is exposed to the app. Anyway to hide that "internal" dependency with dagger?

networkModule's provider declaration:

@Provides
fun provideBooksService(okHttpClient: OkHttpClient): BooksService {
  return NetworkBackedBooksService(okHttpClient)
}

@Provides
fun provideLibraryService(okHttpClient: OkHttpClient): LibraryService {
  return NetworkBackedLibraryService(okHttpClient)
}

@Provides
fun providesHttpClient(): OkHttpClient {
  return //...
}

Dave Scheck

02/14/2023, 9:29 PM

I understand that you can use

Assisted Injection

to pass runtime parameters into objects being injected. What I haven't been able to figure out is how to use that (or another mechanism) to choose the type of object being injected based on a runtime parameter. For example, without using DI I might do something like this

class RepoDataSourceScreenViewModel: ViewModel() {
    var isSimulated = lookupIsSimulated()

    val repository = ComponentRepository(isSimulated)
    
    // This would be backed by a DB/sharedPref lookup
    private fun lookupIsSimulated(): Boolean  = false
    
}

class ComponentRepository(val isSimulated: Boolean) {
    val dataSource = if(isSimulated) RealComponentDataSource() else SimComponentDataSource()
}

abstract class ComponentDataSource()
class RealComponentDataSource() {}
class SimComponentDataSource() {}

Is there an equivalent be in a Dagger/Hilt environment?

ursus

02/19/2023, 2:26 AM

When dagger moves to KSP, is it then KMM ready by default? or more work is needed

Colton Idle

02/23/2023, 10:20 PM

If I'm using dagger/hilt and I have a bunch of gradle modules. And each gradle module provides their own OkhttpInterceptor for example, is it possible to grab all available objects of that type and add them all to okhttps interceptor list?

Title

Colton Idle

02/23/2023, 10:20 PM

ralf

02/23/2023, 10:20 PM

https://dagger.dev/dev-guide/multibindings.html

Note that the order for interceptors matters. Multibindings does not provide any order guarantees.

Colton Idle

02/23/2023, 10:23 PM

Oof. I wonder if there's any way around that.

Thanks though. I forgot that multibindings were the name for that. lets see if that actually helps me out in my situation. cheers

Maybe I can provide

Interceptor

types, but I can maybe check to see what concrete type it actually is... and if it's something important where ordering matters, then I can re-order it by hand before i pass it into my okhttp client in the app module.

ephemient

02/23/2023, 10:38 PM

you could always add some decoration around it, e.g.

data class PrioritizedInterceptor(
    val priority: Int,
    val interceptor: Interceptor,
)
@[Provides IntoSet] fun first() = PrioritizedInterceptor(0, OuterInterceptor)
@[Provides IntoSet] fun last() = PrioritizedInterceptor(Int.MAX_VALUE, InnerInterceptor)
@Inject constructor(interceptors: Set<@JvmSuppressWildcards PrioritizedInterceptor>) {
    for ((_, interceptor) in interceptors.sortedBy { it.priority }) {
        addInterceptor(interceptor)

Colton Idle

02/23/2023, 10:39 PM

My current solution kinda defeats the purpose maybe of having these interceptors in separate modules, but just using @Named("blah") Interceptor seems to get the job done for my scenario here. multi modules, dependency graph, etc makes my head hurt

@ephemient very nice little wrapper

FWIW. My use case right now is actually that for whatever reason I have two http clients in two separate modules. and i want to share one interceptor from module1 to module2, but i dont want module2 to depend on module1. I feel like my solutions are: 1. create a seperate module with these interceptors, and module1 and module2 depend on that new intercept-module 2. Provide the module 1 interceptor (either by multi binding or a @Named) and grab the interceptor from module2 that way

ephemient

02/23/2023, 10:43 PM

usually creating multiple OkHttpClients is a bad thing

https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/ hmm, the formatting was nicer in the old javadocs…

Colton Idle

02/23/2023, 10:52 PM

Yeah. We know the multiple okhttp clients is "bad" but we're in the midst of killing 1. For the time being we just need this as a temporary layer. I guess I can revisit sharing a single okhttp client as then I wouldn't have to repeat interceptors and such.

Actually. I don't think we can share okhttp clients since the new http client needs an additional header.

ephemient

02/23/2023, 10:55 PM

use

newBuilder()

from the shared client, it'll let you build a new instance while sharing the executor etc. (as the docs say)

Colton Idle

02/23/2023, 11:03 PM

ooooh.

lazy meme. replace the text with "is this my solution?" lmaoo

@ephemient i think that pretty much works perfect. So I'm just going to share my http client from module1 to 2 using a named qualifier. then just add my one extra intercept/header via newBuilder() CLUTCH

Daniel Perez

02/24/2023, 7:22 PM

That's what we do. We have a single OkHttpClient in our app that every other client ultimately creates itself from using newBuilder(). It works really nicely and it recycles the thread pool under the hood. Here's the talk I learned it from: https://m.youtube.com/watch?v=t34AQlblSeE

Colton Idle

02/25/2023, 7:03 PM

@Daniel Perez thanks for the link and @jw thanks for the presentation. that was awesome. so many cool little tricks i wanna implement now. cheers both

Daniel Perez

02/25/2023, 7:04 PM

It's a fire talk that holds up pretty well

Colton Idle

02/25/2023, 7:04 PM

pretty much expalined my use case directly. a "base" okhttp client, and then i can add a few more interceptors for whichever service i need.

holds up very well! And I still agree that jake should update u2020 even 6 years later. lmao and i guess the whole retrofit interceptor thing never came to be. lol

ursus

03/04/2023, 9:04 PM

Yea I was about to say what others did, built the priority into the registered type i.e.

Priority(1, FooInterceptor())

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