Kotlin bundle returning null

Question

I cannot get bundle (argument) value in my destination fragment, always return null.

navigation file

Commented.

<fragment
    android:id="@+id/nav_home"
    android:name="com.my.app.ui.home.HomeFragment"
    android:label="@string/menu_home"
    tools:layout="@layout/fragment_home" >
    <argument android:name="projectSlugArgument" />
    <action
        android:id="@+id/action_nav_home_to_projectDetailsFragment"
        app:destination="@id/projectDetailsFragment" />
    <argument android:name="searchArgument" /> // <------- sending argument
    <action
        android:id="@+id/action_nav_home_to_searchFragment"
        app:destination="@id/searchFragment" />
</fragment>
<fragment
    android:id="@+id/projectDetailsFragment"
    android:name="com.my.app.ui.ProjectDetails.ProjectDetailsFragment"
    android:label="fragment_project_details"
    tools:layout="@layout/fragment_project_details">
    <argument android:name="projectSlugArgumentValue"
        app:argType="com.my.app.classes.slugArg" />
    />
</fragment>

<fragment
    android:id="@+id/searchFragment"
    android:name="com.my.app.ui.search.SearchFragment"
    android:label="fragment_search"
    tools:layout="@layout/fragment_search">
    // <------- receiving argument  --------->
    <argument android:name="searchArgumentValue"
        app:argType="com.my.app.classes.slugArg" />
</fragment>

sending argument

private fun search(input: String) {
  val bundle = bundleOf("searchArgument" to input)
  navController.navigate(R.id.action_nav_home_to_searchFragment, bundle)
  Log.d("eeet", input) // has data in Logcat
}

receiving data

lateinit var searchArgument: String

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,savedInstanceState: Bundle?): View? {
  // Inflate the layout for this fragment
  val root = inflater.inflate(R.layout.fragment_search, container, false)

  searchArgument = activity?.intent?.extras?.getString("searchArgument").toString()

  Log.d("eeee", searchArgument) // retuning null in Logcat
  return root
}

Answer 1

You're trying to access the activities arguments here. What you need to do is access the fragments arguments, which can be done with Fragment.getArguments() .

---

However I would recommend taking a deeper look into the navigation component. It isn't recommended to handle the arguments manually, but to use directions .

Answer 2

The Navigation component has a Gradle plugin called Safe Args that generates simple object and builder classes for type-safe navigation and access to any associated arguments. Safe Args is strongly recommended for navigating and passing data, because it ensures type-safety.

See the link above for information on how to add Safe Args for Kotlin. After that is done, your code would look like this:

Sending:

private fun search(input: String) {
  val action =  HomeFragmentDirections.action_nav_home_to_searchFragment(input)
  navController.navigate(action)
  Log.d("eeet", input)
}

Receiving:

private val args: SearchFragmentArgs by navArgs()

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,savedInstanceState: Bundle?): View? {
  // Inflate the layout for this fragment
  val root = inflater.inflate(R.layout.fragment_search, container, false)

  Log.d("eeee", args.searchArgumentValue)
  return root
}