Updating appstate without useraction

[SGuzel]

Hi all,
i have some card items to layout within a listview which are stored in an appstate but the ui changes do not triggered by any user. The ui should only be updated by a server which has the itemstates too. The server streams the new item states constantly.

Like

Item { ValueChanged<bool> isConnected; }

Client.isConnected.addlistener( handleChange )
handleChange(){ updateAppState () ) ---> rebuild Widgets

How can I archieve this?
Maybe a litte help or example?

Thank you .

[brianegan]

Hey hey -- in this case, you'll want to use a Middleware function! It will be responsible for connecting to the Stream of information at the correct time, and dispatching actions when new data comes in.

This article does a good job of explaining the process, using Firestore as the Streaming data source: https://medium.com/shift-studio/flutter-redux-and-firebase-cloud-firestore-in-sync-2c1accabdac4

[SGuzel]

Hi again, thank you very much. That seems to be the solution. I already have middleware but somehow I could not connect the middleware to the grpc/protobuf client which is streaming the notifications.

;)

[brianegan]

Ah, gotcha! Yah, hopefully you can just do a myGrpcClient.dataStream.listen((data) => store.dispatch(ReceivedPayloadAction(data)) inside your Middleware and you'll be all good!

Please let me know if I can help further :)

[SGuzel]

Thank you very much i will just try it out. Since the app is getting more complicated, I changed my mind and try to use redux instead of managing the state manually.

I appreciate it very much. thank you for answering so quickly.

[SGuzel]

I have now a working version of my code using redux and grpc client. Thank you @brianegan