Passing data between Fragments in the same Activity

Question

Am working in a project with an Activity that host many fragments. Now I need to share some data (integers, strings, arraylist) between these fragments.

First time i use

Answer 1

Use a SharedViewModel proposed at the official ViewModel documentation

First implement fragment-ktx to instantiate your viewmodel more easily

dependencies {
implementation "androidx.fragment:fragment-ktx:1.2.2"
}

Then, you just need to put inside the viewmodel the data you will be sharing with the other fragment

class SharedViewModel : ViewModel() {
    val selected = MutableLiveData()

    fun select(item: Item) {
        selected.value = item
    }
}

Then, to finish up, just instantiate your viewModel in each fragment, and set the value of selected from the fragment you want to set the data

Fragment A

class MasterFragment : Fragment() {

    private val model: SharedViewModel by activityViewModels()

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        itemSelector.setOnClickListener { item ->
        model.select(item)
      }

    }
}

And then, just listen for this value at your Fragment destination

Fragment B

class DetailFragment : Fragment() {

        private val model: SharedViewModel by activityViewModels()

        override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
            super.onViewCreated(view, savedInstanceState)
            model.selected.observe(viewLifecycleOwner, Observer { item ->
                // Update the UI
            })
        }
    }

This answer can help you, https://stackoverflow.com/a/60696777/6761436