Hi guys What is the recommended way to use Kotlin interface kotlinlang #android-architecture

Hi guys, What is the recommended way to use Kotlin interface delegation in Android classes? I use a Fragment and want to "delegate" some portion of logic in that fragment to separate class. This way, I can use Kotlin interface delegation to reduce code in main fragment. Basically,

Copy code

class SomeFragment(viewManager: SomeViewManager) : SomeViewInterface by viewManager {

}

Now I want to pass a

View

SomeViewManager

class. What is the best way to do it? Should I have a setter in

SomeViewManger?

Ianmedeiros

02/19/2020, 5:17 PM

It’s not possible to do that with classes that are managed by the framework: i.e. fragments / dialogfragments / activities / etc.

What you can do is to remove the fragment logic to another class and compose it instead.

And the fragment is the one that build this class. Fragments / Activities are composition roots to your classes

ghedeon

02/19/2020, 6:24 PM

maybe with a FragmentFactory tho..

Ianmedeiros

02/19/2020, 6:44 PM

Only API 28+

ghedeon

02/20/2020, 7:09 AM

aren't you talking about

AppComponentFactory

FragmentFactory

is from androidx and I can't see any restrictions.

BMG

02/20/2020, 7:33 AM

@ghedeon @Ianmedeiros Thanks for the points! I didn't know about

FragmentFactory

! With that, can I inject

SomeViewManager

and have a

setter

to set the view once

onViewCreated

is called?

ahulyk

02/20/2020, 10:37 AM

with

FragmentFactory

you can inject

SomeViewManager

Ianmedeiros

02/20/2020, 2:05 PM

FragmentFactory only works on devices with API28+

are you willing to set your minimum target as api 28 and have no user base?

hehe

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