Non-auto disposed provider vs auto disposed with maintainState = true

[wujek-srujek]

What is the difference between a non-'auto disposed' provider vs an 'auto disposed' one with maintainState set to true? It seems to me that they do pretty much the same thing. When debugging, the callback passed to ref.onDispose is never called when maintainState = true, i.e. the same as simply not making the provider 'auto disposed'. What am I missing?

[rrousselGit]

In terms of behaviour, they are similar.

The real difference is in terms of debugging.

It is purposefully not allowed to read an auto-dispose provider from a non-auto-disposed to avoid mistakes.
Whereas an auto-dispose provider with maintainState = true does not prevent those mistakes.

[iamarnas]

maintainState you can use for all types of providers.

I meant Provider.autoDispose(), StateProvider.autoDispose(), StateNotifierProvider.autoDispose() and...

[rrousselGit]

In general, use maintainState only if you want to dynamically prevent dispose. Like the doc mentions with https://riverpod.dev/docs/concepts/modifiers/auto_dispose#refmaintainstate

This example maintains the state only if a network requests succeeds.

[wujek-srujek]

I also don't think Flutter will dispose a non-autoDipsosed provider.

Have you tried to debug it and compare?

@iamarnas just for completeness, I have just checked with the latest riverpod version - PageA sets a state in a non-auto-disposed provider and pushes PageB; when PageB is popped, the state in the provider is still there and not disposed. This is exactly the use case for auto-disposing and I don't understand why you said Flutter would dispose it anyway; if it did, what would be the added value of auto-disposed?

[iamarnas]

@wujek-srujek It not dispose because ProviderScope is on the top widget three and keep the all providers state.

[wujek-srujek]

Yes, this is what I meant by this:

I also don't think Flutter will dispose a non-autoDipsosed provider as you say - once added to the riverpod container, it will stay there, right? That's because the container is not going out of scope as it is one of the topmost widgets most of the time. And once in the container, such provider will be available to whoever has access to the provider variable, and in my case re-entering the page would show the previous state, as mentioned above.

to which you said that I should test it, so I did. Many misunderstandings, we have.