Detect if fragment is truly visible in OnResume when being popped from backstack

Question

Imagine the following scenario:

1. Push Fragment A onto BackStack
2. Push Fragment B onto BackStack
3. Push Fragment C onto BackStack

Fragment B tries to make a async web request when its onResume is method is called.

Fragment C has a button called "Clear Backstack" that clears the backstack by calling popBackStackImmediate(null, FragmentManager.POP_BACK_STACK_INCLUSIVE).

When PopBackStackImmediate is called it pops the Fragments off one by one until the stack is cleared. As each fragment is popped the fragment's onResume method is called. For Fragment B, I don't want the async web request to trigger since its going to be immediately destroyed/removed after its popped (because the entire backstack is being cleared).

In this case how can I detect if the entire backstack is being collapsed and skip the async web request on Fragment B in the OnResume method? Note: I'd still want the async web request to execute if Fragment B is popped/displayed by using the Back button.

Note: I'm using the latest compatibility/support library.

Answer 1

Option 1:

Have you determined what other lifecycle methods are being called - if it's only on resume, then move the async call further down in the lifecyle (onCreateView or onAttach for example) so that it's only called when moving through it in the normal manner.

Option 2:

When onResume is called you could do a getFragmentByTag on the fragment which has already been destroyed. If this is null you could then assume that the operation in action is the destruction.

This one seems pretty ugly to me.

Option 3:

Have C pass some flag up to the controlling activity (we'll call it Main), move the async call up, and when B wants to do the web request, have it call up to main to do so. If C has set the "I'm Destroying" flag, then don't perform the request.