I am having 4 fragments in Navigation Graph, Named A, B, C, D, On which i am getting some data from the user.
When i an in a normal flow (A->B->C->D) and press back button everything(back-stack) working fine.
But i have a case in which i have and edit information flow, Suppose user left the form on Fragment D so when user come again on the screen, i have to navigate the user on the same screen i.e. Fragment D. I achieved it via Deep-link.
Now the problem is in the above case there will be no fragment in the Stack other than fragment D. But i need when user press back button it should navigate to Fragment C to Fragment B to Fragment A .
Means i want other Fragments(A,B,C) to add in the back-stack. Can we do the same, if yes, how?
===Here is the code===
my_navigation_graph.xml.
<fragment
android:id="@+id/aFragment"
android:name="in.demo.project.AFragment"
android:label="AFragment"
tools:layout="@layout/fragment_a_layout">
<deepLink
android:id="@+id/deepLink"
android:autoVerify="true"
app:uri="demo://editflow?is_for_edit={is_for_edit}&step={step}" />
<argument
android:name="is_for_edit"
android:defaultValue="false"
app:argType="boolean" />
<argument
android:name="step"
android:defaultValue="2"
app:argType="string" />
<action
android:id="@+id/action_aFragment_to_bFragment"
app:destination="@id/bFragment"/>
<action
android:id="@+id/action_aFragment_to_cFragment"
app:destination="@id/cFragment"/>
<action
android:id="@+id/action_aFragment_to_dFragment"
app:destination="@id/dFragment"/>
<fragment
android:id="@+id/bFragment"
android:name="in.demo.project.BFragment"
android:label="BFragment"
tools:layout="@layout/fragment_b_layout">
<action
android:id="@+id/action_bFragment_to_cFragment"
app:destination="@id/cFragment" />
</fragment>
<fragment
android:id="@+id/cFragment"
android:name="in.demo.project.CFragment"
android:label="CFragment"
tools:layout="@layout/fragment_c_layout">
<action
android:id="@+id/action_cFragment_to_dFragment"
app:destination="@id/dFragment" />
</fragment>
<fragment
android:id="@+id/dFragment"
android:name="in.demo.project.DFragment"
android:label="DFragment"
tools:layout="@layout/fragment_d_layout">
</fragment>
Navigating through.
findNavController().navigate(AFragmentDirections.actionAFragmentToBFragment())
Inside AFragment i am redirecting to other fragment, assuming that creating deep-link to every fragment is not good practice.
This code is in onCreate()
Method of AFragment
arguments?.let {
if (AFragmentArgs.fromBundle(it).isForEdit) {
redirectionForEdit(AFragmentArgs.fromBundle(it).step)
}
}
and a function for redirection
private fun redirectionForEdit(step: String) {
when (step) {
"2" ->
findNavController().navigate(AFragmentDirections.actionAFragmentToBFragment())
"3" ->
findNavController().navigate(AFragmentDirections.actionAFragmentToCFragment())
"4" ->
findNavController().navigate(AFragmentDirections.actionAFragmentToDFragment())
}
}
Now if i get 4 in the step it'll redirect to DFragment, so the stack would be A->D, but i want B & D into the stack too (A->B->C->D).
For this please refer handling custom back navigation under navigation components
OnBackPressedCallback callback = new OnBackPressedCallback(true /* enabled by default */) {
@Override
public void handleOnBackPressed() {
// Handle the back button event
}
};
requireActivity().getOnBackPressedDispatcher().addCallback(this, callback);