<@UHAJKUSTU> how can i trigger the back intercepto...

# decompose

[Vaibhav Jaiswal]

@Arkadii Ivanov how can i trigger the back interceptor when i navigate back manually by calling navigator.pop() from the app bar button or so
When the BackHandler is added by some specific component in the stack nav

Eg:

--- Root Component (Stack Nav) (Has the app bar with back button)
------- Screen 1 (Adds back handler)

[Arkadii Ivanov]

It's not possible. BackHandler is not used when you navigate manually.

There are two alternatives.

1. You can bubble your Back request up to the root level and call the back dispatcher. E.g. call OnBackPressedDispatcher#onBackPressed on Android, or BackDispatcher on all other platforms.

2. You can try creating a custom ComponentContext that would have a back() method in it, and that would call the root back dispatcher for you. I never tried this option, but I guess it should be possible.

[Vaibhav Jaiswal]

Any possible way to get all the back handlers attached to the root context based on tag or some field?

[Arkadii Ivanov]

I'm not sure I understand what you mean.

[Arkadii Ivanov]

All BackHandlers are somewhat attached to the root.

[Vaibhav Jaiswal]

Anyway to get a list of all?

[Vaibhav Jaiswal]

Or find a back handler?

[Vaibhav Jaiswal]

What i was thinking was to keep a back handler inside the "BaseComponent" class i have and invoke the back handler when app bar back button is pressed instead of just navigator.pop()
Would this work?

[Arkadii Ivanov]

I don't think it would work. Each child ComponentContext has its own BackHandler, attached to the parent ComponentContext. So there is a tree of BackHandlers.

[Vaibhav Jaiswal]

It did work

childStack.value.active.instance.component.backCallback?.onBack() ?: navigation.pop()

Calling this on app bar back press
If any component in stack nav has a custom back handler, it will be invoked

[Arkadii Ivanov]

This assumes that the backCallback is the only callback in the child component. There could be another BackCallback somewhere in the sub-tree.

[Arkadii Ivanov]

But glad if it works for your case.

[Vaibhav Jaiswal]

yeah, if there is any more back callbacks, deeper in the tree
It wont work