CODEWITHSUNDEEP
flutterfirebasedartgoogle-cloud-firestore
cueless
cueless

Reputation: 121

How to handle statemanagment in flutter to listen to document changes in firestore?

Im building an app with a backend on firestore.

Architecture:

This is the relevant route of screens the user can take in my app:

Home-> myOrdersList(FutureBuilder)-> OrderInfo(FutureBuilder)-> HandleOrder.

to get the futures and handle my order I have this class:

class FirestoreService 

functions:
Future List GetOrders;
Future Order getOrder;

Future void changeOrderInfo;

Order class:

class Order

parameters:
String info;

This is the problem:

When the calls FirestoreService().changeOrderInfo on HandleOrder-screen the screen pops to OrderInfo-screen. The SpecificOrder-screen automaticly rebuilds with setState so thats works fine and the changed info is up to date here. But when the user navigates one screen backwards in the stack to myOrdersList (where all current orders are listed) that screen still holds the old data that was fetched before the order was handled. So not before the user manually updates the screen you can se the current state and the changed info on that screen.

My question:

So I wonder if there is a simple stateManagement technique to solve this problem in a simple way. One way I have thought of is to use changenotifier in FirestoreService, and notifyallisteners when the function changeOrderInfo is called to then notify all relevant screens and get them up to date but I dont really know if thats correct. Since there are many orders and new ones are continuously created I cant simply listen on one document and provide those changes.

One solution could also be to use a streambuilder in myOrdersList but i dont like that solotion since it would mean that data would be fetched everytime any order was changed

Upvotes: 0

Views: 46

Answers (1)

john
john

Reputation: 1998

if you are after real-time updates stream builder is the only way to go. unless you want to refresh your future builder again and again every time there is an update which will kill your wallet because that means you are refetching all the documents again and again. Unlike stream builder, you only fetch the collection once and if there is an update, it will only refetch the document changed/updated not the whole collection. check this out for more explanation https://firebase.google.com/docs/firestore/query-data/listen

Upvotes: 1

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