Add (not replace) fragment with navigation architecture component

Question

I have an activity with a product list fragment and many other fragments and I am trying to use architecture component navigation controller.

The problem is: it replaces

Answer 1

You have to override NavHostFragment's createFragmentNavigator method and return YourFragmentNavigator.

YourFragmentNavigator must override FragmentNavigator's navigate method.

Copy and paste FragmentNavigator's navigate method to your YourFragmentNavigator.

In navigate method, change the line ft.replace(mContainerId, frag); with

if (fragmentManager.fragments.size <= 0) {
    ft.replace(containerId, frag)
} else {
    ft.hide(fragmentManager.fragments[fragmentManager.fragments.size - 1])
    ft.add(containerId, frag)
}

The solution will look like this:

class YourNavHostFragment : NavHostFragment() {
override fun createFragmentNavigator(): Navigator<...> {
    return YourFragmentNavigator(...)
}}

....

class YourFragmentNavigator(...) : FragmentNavigator(...) {

override fun navigate(...){
    ....
    if (fragmentManager.fragments.size <= 0) {
        ft.replace(containerId, frag)
    } else {
        ft.hide(fragmentManager.fragments[fragmentManager.fragments.size - 1])
        ft.add(containerId, frag)
     }
     ....
}}

in your xml use YourNavHostFragment.