<@U0BLRBFMM> I have: ``` bind&lt;ProgressNotifier&gt;() with factory { id: Int, iconRes: Int, tit...

# kodein

[dave08]

@salomonbrys I have:

bind<ProgressNotifier>() with factory { id: Int, iconRes: Int, title: String ->
        ProgressNotifierImpl(instance(), id, iconRes, title)
    }

    bind() from singleton { InstallationNotifier(factory() as ((Int,Int,String) -> ProgressNotifier)) }

But idea tells me that type inference failed for A on factory() call in the InstallationNotifier constructor... how could I acheive this? the constructor takes: val progressNotifierFactory: (id: Int, iconRes: Int, title: String) -> ProgressNotifier

[Andreas Sinz]

@dave08 you need to tell factory what type of Factory you want, try InstallationNotifier(factory<(Int, Int, String) -> ProgressNotifier>())

[Andreas Sinz]

or maybe it could work without any type annotations InstallationNotifier(factory())

[dave08]

I tried that 🤒

[Andreas Sinz]

both ways?

[dave08]

Yup

[Andreas Sinz]

neither of them worked?

[dave08]

nope

[Andreas Sinz]

what are the error messages? still unresolved type?

[dave08]

Type inference failed. Expected type mismatch:
required: (Int, Int, String) -> ProgressNotifier
found: (???) -> ???

[dave08]

That's for factory() by itself

[dave08]

For factory<((Int, Int, String) -> ProgressNotifier)>()

[dave08]

I get:

[Andreas Sinz]

wait a second

[dave08]

that it needs two type arguments like inline fun <reified A, reified T : Any> DKodein.factory(tag: Any? = null)

[Andreas Sinz]

a Factory binding requires you to have a single argument: "This binds a type to a factory function, which is a function that takes an argument of a defined type and that returns an object of the bound type (eg. (A) → T)" http://kodein.org/Kodein-DI/?5.0/core#_factory_binding

[dave08]

But a factory can have many arguments... I think the first one is Multi3 type in my case, but when I tried that, I had even more problems...

[dave08]

Kodein...

[dave08]

inline fun <C, reified A1, reified A2, reified A3, reified T: Any> Kodein.BindBuilder.WithContext<C>.factory(noinline creator: BindingKodein<C>.(A1, A2, A3) -> T)

[Andreas Sinz]

alright, one thing you could try is factory<Multi3<Int, Int, String>, ProgressNotifier>()

[dave08]

Thanks for hanging in there! But no go... I got Multi3<Int, Int, String>(...) expected.
Type mismatch.
Required: (Int, Int, String) -> ProgressNotifier
Found Multi3<Int, Int, String>

[Andreas Sinz]

hm, then I'm out of guesses

[Andreas Sinz]

As a workaround you could use a data class instead of 3 arguments

[dave08]

Funny no? Thanks anyways for all the help 😉! Maybe @salomonbrys might know, or maybe this is a bug...

[salomonbrys]

OK, so multi-argument factories are in fact... a scam 😉

[dave08]

🤔

[salomonbrys]

A multi-argument factory is in fact a factory that takes a MultiX argument

[salomonbrys]

So, you should try factory() as (Multi3<Int,Int,String>) -> ProgressNotifier

[salomonbrys]

Or, if you want to set the factory function parameters, you need to give all parameters (the argument and the return type) : `factory<Multi3<Int,Int,String>,ProgressNotifier>()

[dave08]

Still no go, since my constructor takes (Int, Int, String) -> ProgressNotifier, and you're passing it a Multi... meaning I'd have to define the constructor to depend on Kodein... pretty big no no...

[salomonbrys]

OK, give me a second 😉

[salomonbrys]

@dave08 You're using generic or erased ?

[dave08]

generic

[salomonbrys]

Add this to your project :

[salomonbrys]

import org.kodein.di.*

inline fun <reified A1, reified A2, reified A3, reified T : Any> DKodein.factory3(tag: Any? = null): ((A1, A2, A3) -> T) {
    val f = Factory<Multi3<A1, A2, A3>, T>(generic(), generic(), tag)
    return { a1, a2, a3 -> f(Multi3(a1, a2, a3, generic())) }
}

[salomonbrys]

Then this should work :
bind() from singleton { InstallationNotifier(factory3()) }

[salomonbrys]

I'll add these function for Kodein as well as DKodein and for 2 to 5 parameters in next release 😉

[salomonbrys]

I hadn't thought of this use case

[dave08]

Nope:

Process: com.lomdaat.coreservices.kosherstore, PID: 27116
    java.lang.ClassCastException: libcore.reflect.TypeVariableImpl cannot be cast to java.lang.Class
        at org.kodein.di.ParameterizedTypeToken.getRawType(types.kt:177)
        at org.kodein.di.ParameterizedTypeToken.getRaw(types.kt:202)
        at org.kodein.di.TypeToken$DefaultImpls.isAssignableFrom(typeToken.kt:82)
        at org.kodein.di.JVMTypeToken.isAssignableFrom(types.kt:143)
        at org.kodein.di.ClassTypeToken.isAssignableFrom(types.kt:302)
        at org.kodein.di.TypeToken$DefaultImpls.isAssignableFrom(typeToken.kt:89)
        at org.kodein.di.JVMTypeToken.isAssignableFrom(types.kt:143)
        at org.kodein.di.internal.TypeChecker$Down.check(KodeinTreeImpl.kt:12)
        at org.kodein.di.internal.KodeinTreeImpl$findBySpecs$3.invoke(KodeinTreeImpl.kt:71)
        at org.kodein.di.internal.KodeinTreeImpl$findBySpecs$3.invoke(KodeinTreeImpl.kt:28)
        at kotlin.sequences.FilteringSequence$iterator$1.calcNext(Sequences.kt:110)
        at kotlin.sequences.FilteringSequence$iterator$1.hasNext(Sequences.kt:133)
        at kotlin.sequences.FlatteningSequence$iterator$1.ensureItemIterator(Sequences.kt:249)
        at kotlin.sequences.FlatteningSequence$iterator$1.hasNext(Sequences.kt:241)
        at kotlin.sequences.FilteringSequence$iterator$1.calcNext(Sequences.kt:108)
        at kotlin.sequences.FilteringSequence$iterator$1.hasNext(Sequences.kt:133)
        at kotlin.sequences.TransformingSequence$iterator$1.hasNext(Sequences.kt:153)
        at kotlin.sequences.SequencesKt___SequencesKt.toCollection(_Sequences.kt:654)
        at kotlin.sequences.SequencesKt___SequencesKt.toMutableList(_Sequences.kt:684)
        at kotlin.sequences.SequencesKt___SequencesKt.toList(_Sequences.kt:675)
        at org.kodein.di.internal.KodeinTreeImpl.findBySpecs(KodeinTreeImpl.kt:81)
        at org.kodein.di.internal.KodeinTreeImpl.find(KodeinTreeImpl.kt:99)
        at org.kodein.di.KodeinTree$DefaultImpls.find$default(KodeinTree.kt:32)
        at org.kodein.di.internal.KodeinContainerImpl.factory(KodeinContainerImpl.kt:146)
        at org.kodein.di.KodeinContainer$DefaultImpls.factory$default(KodeinContainer.kt:33)
        at org.kodein.di.internal.DKodeinBaseImpl.Factory(DKodeinImpl.kt:21)
        at org.kodein.di.internal.BindingKodeinImpl.Factory(KodeinImpl.kt)
        at org.kodein.di.bindings.BindingKodeinContextWrap.Factory(standardBindings.kt)
        at org.kodein.di.bindings.NoArgBindingKodeinWrap.Factory(BindingKodein.kt)

[dave08]

It compiles, but crashes on Android device...

[salomonbrys]

OK, I'm at a conf, I'll handle this as soon as I can 😉

[dave08]

Thanks! Let me know.. simple smile

[dave08]

@salomonbrys Any news on this?

[salomonbrys]

This is a limitation of reified generics:

[salomonbrys]

inline fun <reified A1, reified A2, reified A3> multi3Generic() = generic<Multi3<A1, A2, A3>>()

fun main(args: Array<String>) {

    println(generic<Multi3<String, String, Int>>().simpleDispString())
    // Multi3<String, String, Int>
    
    println(multi3Generic<String, String, Int>().simpleDispString())
    // Multi3<A1, A2, A3>
}

[salomonbrys]

So, this is looks quite complicated to fix, if fixable at all.

[salomonbrys]

Right now, I would advise you to use a data class

[salomonbrys]

I'll investigate more when I have time 😉

[dave08]

So with one param it'll work? I guess I'll have to do that, thanks for looking into this anyways. 👍🏼