Android Jetpack Navigation in multi modular apps

I will be demonstrating about the following topic in Jetpack Navigation

• Using navigation in multi-modular apps
• Using nested fragments in jetpack navigation
  helpful when creating bottom navigation view, or having common action bar in some section of app or many more
• Source code for the demonstrated project ,
  This is a multi-modular single activity project that uses dagger2, clean architecture, room db, Jetpack Navigation

Demo

Nested graph Preview

nav_graph_app_module is the app module’s graph
We will reference this graph in our activity_main.xml , fragment container
We include nav_graph_home_host here as it is another module and to navigate to that module we simply navigate to nav_graph_home_host graph

Navigate from splash to home
findNavController().navigate(R.id.nav_graph_home_host)

From splash we will navigate to nav_graph_home_host graph,
this graph contains a fragment HomeHostFragment
HomeHostFragment contains an bottom nav view and a fragment container
as we are dealing with nested fragment so to avoid stack overflow issue
and also to keep things simple
we will create another graph nav_graph_home containing all other fragments we need in this module

nav_graph_home includes multiple graph from different modules
Each graph is associated with menu click of bottom nav view
To achieve navigation we will keep bottom navigation id same as graph’s id
check the Github source code for complete insight

Code to set up bottom navigation with navigation graph

bottonNavView.setupWithNavController(navController)

Now stack is like ::
splash → home
(home will not maintain any stack as navHost is set to default i.e., false)

Now if we want to navigate from home to other fragment
but wanted to host from our root nav controller, then can use the below function

/*
  `R.id.fragment_container_root` is id of our root fragment 
   which we inflated in Main Activity
*/
val Fragment.findRootNavHost: NavController?
get() = this.activity?.let { 
    Navigation.findNavController(it, R.id.fragment_container_root) 
}

In fragment from where we want to navigate

findRootNavHost?.navigate(`your_destination_fragment`)

I’d like to end this post by saying thank you 🙏 for reading
If have any query we can connect, links in my profile or you can comment it down