2.0 Migration Problem..

[Patrick386]

I am working on a 2.0 migration.
I used the Riverpod StreamProvider, and I have a problem.

final CollectionReference<ServiceProductModel> serviceProductCollectionRef = firebaseFirestore .collection(SERVICE_PRODUCT_COLLECTION) .withConverter<ServiceProductModel>( fromFirestore: (DocumentSnapshot<Map<String, dynamic>> snapshot, _) => ServiceProductModel.formJson(snapshot.data()!), toFirestore: (ServiceProductModel model, _) => model.toJson());

final AutoDisposeStreamProvider serviceProductStreamProvider =
    AutoDisposeStreamProvider((AutoDisposeProviderReference ref) {
  return serviceProductCollectionRef.snapshots(); //.map((QuerySnapshot<ServiceProductModel> snapshot) => snapshot.docs); //.map((event) => event.docs);
});

 Widget build(BuildContext context) {
     AsyncValue _svrProdStream =
        useProvider(serviceProductStreamProvider); 

return _svrProdStream.when(
      **data: (serviceProduct) {** <<-- **I don't know what type it is, so it makes me confusing.**
       .....
      }

1. Is it possible to get'List' via stream?
2. I need an example for StreamProvider.
   Thank you.

[stargazing-dino]

When writing code snippets, make sure they're legible for others to better help you.

Please use highlighting and proper formatting. Darts language code is dart.

As for a way you can create a stream of product docs (if this is what you want) you can creating a stream of the snapshots and then consume that stream in another provider that exposes just the docs (This helps you separate concerns, the mapping of docs from the source stream).

final serviceProductSnapshotsProvider =
    StreamProvider.autoDispose<QuerySnapshot<ServiceProduct>>(
  (ref) => serviceProductCollectionRef.snapshots(),
);

final serviceProductDocsProvider =
    Provider.autoDispose<AsyncValue<List<DocumentSnapshot<ServiceProduct>>>>(
  (ref) {
    return ref.watch(serviceProductSnapshotsProvider).whenData((snapshot) {
      return snapshot.docs;
    });
  },
);

Or, if you prefer to just get the docs, you can do

final serviceProductDocsProvider =
    StreamProvider.autoDispose<List<QueryDocumentSnapshot<ServiceProduct>>>(
  (ref) => serviceProductCollectionRef.snapshots().map((snapshot) => snapshot.docs),
);

[Patrick386]

final serviceProductDocsProvider =
    StreamProvider.autoDispose<List<QueryDocumentSnapshot<ServiceProduct>>>(
  (ref) => serviceProductCollectionRef.snapshots().map((snapshot) => snapshot.docs),
);

The length of docs and the documentation could not be read.
How should I read it?
It's rather confusing as the Type isn't clear.

Error
Another exception was thrown: NoSuchMethodError: 'name'

Widget build(BuildContext context) {
  
    AsyncValue _svrProdDocs = useProvider(serviceProductDocsProvider);

    return _svrProdDocs.when(
      loading: ...
      error:  ...
      data: (prodDoc) {  //<< dynamic prodDoc ?
   
      **How do you read the data here?**
      print('serviceProduct: ${prodDoc[0].name}');
    
...
}
}

[stargazing-dino]

The length of docs can be read by snapshot.size if i remember or you can just get the call len on the returned list value of serviceProductDocsProvider .

In your code you override the type of _svrProdDocs as AsyncValue

// Now becomes AsyncValue<dynamic>
AsyncValue _svrProdDocs = useProvider(serviceProductDocsProvider);

Therefore you lose type information. You can either use final or type it fully as what it is

final _svrProdDocs = useProvider(serviceProductDocsProvider);
// or
AsyncValue<List<QueryDocumentSnapshot<ServiceProduct>>> _svrProdDocs = useProvider(serviceProductDocsProvider);

When you do that, prodDoc will no longer be dynamic

To get that data, you can just call .data() on the snapshot

final ServiceProduct product = prodDoc.data();

If all you wanted was your list of ServiceProducts from the start, you can just change your provider like this

final serviceProductDocsProvider =
    StreamProvider.autoDispose<List<ServiceProduct>>(
  (ref) => serviceProductCollectionRef.snapshots().map((snapshot) => snapshot.docs.map((doc) => doc.data())),
);

[Patrick386]

I fully understood the method presented, but did not get the desired result. I've tried several methods, but I can't.
All packages prior to migration were up to date and worked fine.
I followed the migration documentation, but I can't read the data from the server.
I tested it again using the sample StreamBuilder from the documentation.
There is an error in the sample and I cannot get the desired result again.

final AutoDisposeStreamProvider serviceProductDocsProvider =
    StreamProvider.autoDispose<List<ServiceProductModel>>(
        (AutoDisposeProviderReference ref) => serviceProductCollectionRef
            .snapshots()
            .map((QuerySnapshot<ServiceProductModel> snapshot) => snapshot.docs
                .map((QueryDocumentSnapshot<ServiceProductModel> doc) =>
                    doc.data())
                .toList()));

══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
The following assertion was thrown building Text("Error Expected a value of type 'String', but got
one of type 'Null'", dependencies: [DefaultTextStyle, MediaQuery]):

cloud_firestore: ^ 2.0.0
flutter_hooks: ^ 0.16.0
hooks_riverpod: ^ 0.14.0 + 3
freezed_annotation: ^ 0.14.1
json_annotation: ^ 4.0.1

[Patrick386]

It has been determined that the word for an unused field in the model is incorrect. I found that what was ignored before 2.0 works very strict. I went through all of the sources one by one and I ended up with a 2.0 migration success.
Thank you.