Hey guys, I'm using Butterknife in a mixed Java/Ko...

# android

[Mathbl]

Hey guys, I'm using Butterknife in a mixed Java/Kotlin project. I'm used to declare views as lateinit var ex.:
@BindView(R.id.swipe_refresh_layout) lateinit var swipeRefreshLayout: SwipeRefreshLayout, that's fine right?

To be able to show the loading animation of SwipeRefreshLayout programmatically, I use this method:

fun showLoading() {
        <http://swipeRefreshLayout.post|swipeRefreshLayout.post>({ 
            swipeRefreshLayout.isRefreshing = true 
        })
    }

This is inside a fragment, inside a viewpager/tabs. Thing is, I have a case (I supposed that it's because I unbind in onDestroyView) where sometimes the swipeRefreshLayout variable is null once inside the post block. It seems it has to do with the tab/fragment not being visible so I thought I'd check inside post if (isAdded) but no luck there. Any idea?

[gildor]

Doesn’t look related to Kotlin.
Maybe your function called before injection of views in some case

[Mathbl]

Yeah, one could argue it's semi related but at the same time, it is: It's more of a general question about the use of lateinit for views and if it's the right way in this case.

[Mathbl]

The thing is, even if I explicitly check for null here, the fact that the variable is lateinit, it will still throw an exception.

[gildor]

you can use prop::isInitilized
https://kotlinlang.org/docs/reference/properties.html#checking-whether-a-lateinit-var-is-initialized-since-12

[gildor]

Also if some property can be null just use nullable type instead of lateinit

[Mathbl]

Interesting, I'll check the isInitialized method, thanks.

[gildor]

Actually in this case nullable is completely fine:

swipeRefreshLayout?.isRefreshing = true

much better than isInitilized check.

[gildor]

what is your case here? Maybe easier to inject views onCreate to avoid such situation