AutoCleared.md

AutoCleared

autoCleared is a delegate for a read/write property that clears its value when the fragment's view is destroyed.

viewLifecycleAware has the same behavior as autoCleared by default, so you can easily replace one with the other:

var adapter by viewLifecycleAware<MyAdapter>()

If you don't want to replace delegates in already written code or just want to keep the familiar name, you can write your own extension:

fun <T : Any> Fragment.autoCleared() = viewLifecycleAware<T>()

In a similar way, you can implement the autoCleared extension with support for a callback that is called in response to a property cleanup event:

@OptIn(LifecycleAwareConfigurationApi::class)
private class AutoClearedConfiguration<T : Any>(
    private val beforeClearProperty: (property: T) -> Unit = { /* no-op */ }
) : LifecycleAwareReadWriteConfiguration<T> by LifecycleAwareReadWriteConfiguration.Default() {

    override fun onClear(value: T) {
        beforeClearProperty(value)
    }
}

@OptIn(LifecycleAwareConfigurationApi::class)
fun <T : Any> Fragment.autoCleared(
    beforeClearProperty: (property: T) -> Unit = { /* no-op */ }
) = viewLifecycleAware(
    configuration = AutoClearedConfiguration(beforeClearProperty)
)