Android Navigation Component - Implementing Listener

Question

so I'm using the navigation component and something I'm trying to do right now is implement a listener for when the user clicks a button in a dialog. In another fragment, I want to detect when that happens.

In the past, I would just create an interface within the dialog and call the interface's function in the button's onClick. Then in the fragment, I'd set the listener by having a variable for the dialog and calling the set function, with the interface function implemented in the fragment. So like:

dialogFrag.setListener(this)

But with navigation component, I'm not sure how to do this since I've been handling navigation like:

findNavController().navigate(R.id.dialogName)

Any idea how to do this?

There's documentation specifically around [returning a result](https://developer.android.com/guide/navigation/navigation-programmatic#returning_a_result) and even additional documentation [specifically about dialog destinations](https://developer.android.com/guide/navigation/navigation-programmatic#additional_considerations). — ianhanniballake, Jan 03 '21 at 23:04
One way would be using [NavArgs](https://developer.android.com/guide/navigation/navigation-pass-data) and passing a high order function to your dialog where you need to implement it, and you can call it in your dialog. — Khaled Ahmed, Jan 04 '21 at 11:27

score 1 · Answer 1 · answered Apr 21 '21 at 12:11

as mentioned here I will duplicate his solution

Android navigation architecture component

eg:

Suppose you open Fragment B from Fragment A using navController.

and you want some data from fragment B to Fragment A.

class B :BottomSheetDialogFragment() {

override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val root = inflater.inflate(R.layout.your_layout, container, false)

        root.sampleButton.setOnClickListener {
            val navController = findNavController()
            navController.previousBackStackEntry?.savedStateHandle?.set("your_key", "your_value")
            dismiss()

        }
}

and in your Fragment A:

findNavController().currentBackStackEntry?.savedStateHandle?.getLiveData<String>("your_key")
                ?.observe(viewLifecycleOwner) {
    
                    if (it == "your_value") {
                        //your code
    
                    }
    
                }

Android Navigation Component - Implementing Listener

1 Answers1