Coroutine issue / IllegalStateException: View ID [...] for 'view' not found

Disclaimer: Hi, I’ve been using Groupie for the past year, but it is kind of abandoned and EVERYBODY always says good things about epoxy, so I’m here trying to use it and breaking my head. One advice, your examples are really poor, there is 1 for java, 1 for kotlin, and 1 for paging. FastAdapter has like dozens of samples, Groupie itself has a very very complete sample. Wiki is really vague on a few things, like when to use withModels/epoxyController and which kind of ViewHolder is more efficient - there is a comment on KotlinModel saying it is not efficient, and another one on EpoxyModelWithHolder saying it is good. Makes a lot of confusion.

Anyway: I have this code (simplified) in Groupie:

class RowItem(val app: App) : Item(), CoroutineScope {

    private var job: Job = Job()
    override val coroutineContext: CoroutineContext = Dispatchers.Main + job

    override fun unbind(holder: ViewHolder) {
        job.cancel()
        holder.icon.setImageDrawable(null)
        holder.bottom_view.background = null
        super.unbind(holder)
    }

    private val bottomShape = createShape(app.backgroundColor.darken, true)
    private var drawable: Bitmap? = null

    override fun getLayout() = R.layout.row_navigation_item

    override fun bind(viewHolder: ViewHolder, position: Int) {

        viewHolder.label.setTextAsync(app.title)
        viewHolder.bottom_view.background = bottomShape

        job = Job()
        launch {
            cacheDrawable() // PAY ATTENTION TO THIS
            viewHolder.icon?.setImageBitmap(drawable)
        }
    }

    private suspend inline fun cacheDrawable() {
        if (drawable == null) {
            drawable = withContext(Dispatchers.IO) {
                AppManager.getIconFromId(app.packageName)?.toBitmap()
            }
        }
    }
}

So I went ahead and converted it to Epoxy, following your samples:

internal class PhotoController : TypedEpoxyController<List<App>>() {

    override fun buildModels(data: List<App>) {
        data.forEach {
            ItemDataClass(it)
                .id("data class \${app.packageName}")
                .addTo(this)
        }
    }
}

abstract class KotlinModel(
    @LayoutRes private val layoutRes: Int
) : EpoxyModel<View>(), CoroutineScope {

    private var job: Job = Job()
    override val coroutineContext: CoroutineContext = Dispatchers.Main + job

    override fun bind(view: View) {
        job = Job()
        this.view = view
        bind()
    }

    override fun unbind(view: View) {
        job.cancel()
        this.view = null
    }
	// everything else is same as the sample
}

data class ItemDataClass(
    val app: App, val sdkVersion: Int, val lastUpdateTime: String, val cornerRadius: Float
) : KotlinModel(R.layout.row_navigation_item) {

    val icon by bind<ImageView>(R.id.icon)
    val label by bind<AppCompatTextView>(R.id.label)
    val bottom_view by bind<View>(R.id.bottom_view)

    private val bottomShape = createShape(app.backgroundColor.darken, true)
    private var drawable: Bitmap? = null

    override fun bind() {
        label.setTextAsync(app.title)
        bottom_view.background = bottomShape

        launch {
            updateDrawable() // PAY ATTENTION TO THIS
            icon.setImageBitmap(drawable)
        }
    }

    private suspend inline fun updateDrawable() {
        if (drawable == null) {
            drawable = withContext(Dispatchers.IO) {
                AppManager.getIconFromId(app.packageName)?.toBitmap()
            }
        }
    }
}

Did you see the issue already? If I scroll very fast, by using the coroutines (since I don’t want to retrieve a drawable in main thread), when it is done, I believe icon might be null and it explodes with a IllegalStateException because getValue returns null for the view id.

It works perfectly with Groupie and the default RecyclerView. So, my question is, what should I do? Should I just go with viewBinding and forget this?

I am using 3.0.0-rc01.

Edit:

I just converted to DataBinding and… worked fine but first run got REALLY slow (like, from 1~2seconds to 6) since it is not parsing the images async - I don’t need to load them all, if it fetches them as the user scrolls is ok. Is there any strategies to fix this?

Edit 2: (again, almost no samples, which is bad) how are you using glide with it? 🤔

[bernaferrari]

You could link those two sections, I think would help a lot of people. I wouldn’t know if you haven’t linked it, thanks!

[bernaferrari]

Well well, at the end of the day and with a lot of effort, everything is working perfectly! Thanks for all the help!!