Refresh fragment when dialogfragment is dismissed

Question

Is there any way I can detect when a DialogFragment is dismissed, so that i can update its parent fragment?

Answer 1

The top rated answers here have issues.

You cannot hold listeners as instance variables in a DialogFragment, as they will not survive recreation, and you will left wondering why your callbacks 'magically' stop working.

You can read more about this here:

https://medium.com/@lukeneedham/listeners-in-dialogfragments-be636bd7f480

This article offers a couple of real solutions, of which my favourite is to use targetFragment with a custom interface. For intercepting the dismiss, that looks like:

class MainFragment : Fragment(R.layout.fragment_main), DummyDialogCallback {
    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        openDialogButton.setOnClickListener {
            val dialog = DummyDialog()
            dialog.setTargetFragment(this, DIALOG_DUMMY)
            dialog.show(requireFragmentManager(), "DummyDialog")
        }
    }

    override fun onDummyDialogClick() {
        Toast.makeText(requireContext(), "Dummy click", Toast.LENGTH_SHORT).show()
    }

    companion object {
        const val DIALOG_DUMMY = 1
    }
}

class DummyDialog : DialogFragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ) = inflater.inflate(R.layout.dialog_dummy, container, false)

    override fun onDismiss(dialog: DialogInterface) {
        super.onDismiss(dialog)
        val callback = targetFragment as? DummyDialogCallback
        callback?.onDummyDialogClick()
    }
}

interface DummyDialogCallback {
    fun onDummyDialogClick()
}