<@UHAJKUSTU> I’m curious if you’ve ever considered...

# mvikotlin

[Seth Madison]

@Arkadii Ivanov I’m curious if you’ve ever considered adding an analog to redux’s middleware?

I have a few use-cases where it would be convenient to compare old state to new state and then do something outside the store (or fire a label).

[Seth Madison]

Right now I can hack this functionality into a ViewRenderer, but that feels wrong.

[Seth Madison]

I guess the other option is to do it outside the framework by listening to store.states but it would be nice to be able to fire label from this code.

[Arkadii Ivanov]

You can try wrapping your store with another one, that would compare both states and emit labels. You can write a custom StoreFactory that wraps another StoreFactory and does the trick. E.g. LoggingStoreFactory work this way, it adds logging to every store being created.

[Arkadii Ivanov]

For your specific case, perhaps you can just wrap the store, no need to also wrap StoreFactory.

[Seth Madison]

hmm, that makes sense. I’ll take a stab at it.

[Arkadii Ivanov]

However, I find it easier to just observe state changes and perform whatever actions required, instead of sending a Label. By receiving the state change, you can assume you received the Label.

[Arkadii Ivanov]

Or maybe just emit the Label directly from the store, when needed.