Best practices for returning a provider from a provider?

[oodavid]

final userProvider = StreamProvider.autoDispose.family<User, String>((ref, userId) {
  // ...Returns the User stream
});

final companyProvider = StreamProvider.autoDispose.family<Company, String>((ref, companyId) {
  // ...Returns the Company stream
});

final userCompanyProvider = StreamProvider.autoDispose.family<Company?, String>((ref, userId) {
  String? companyId = ref.watch(userProvider(userId).select((user) => user.value?.company!.id));
  // ...What do I do here?
});

In the last provider, I want to return data from the first provider conditionally. Is the following reasonable?:

final userCompanyProvider = Provider.autoDispose.family<Company?, String>((ref, userId) {
  String? companyId = ref.watch(userProvider(userId).select((user) => user.value?.company!.id));
  if (companyId != null) {
    return ref.watch(companyProvider(companyId)).asData?.value;
  }
});

I expected to create another StreamProvider (ie: returning the AsyncData). Provider seems to work, but not sure if I've missed something here?

[rrousselGit]

I do not understand what this is about. But conditionally watching a provider is fine

[oodavid]

I'd like the conditional provider userCompanyProvider to return an AsyncValue just like the userProvider that it watches.

// We can use user.when(...)
AsyncValue<User> user = ref.watch(userProvider);
// But not here 😔
User? userCompany = ref.watch(userCompanyProvider);

[rrousselGit]

Oh, that's because you unwrapped it.

You can do:

final userCompanyProvider = Provider.autoDispose.family<AsyncValue<Company>?, String>((ref, userId) {
  String? companyId = ref.watch(userProvider(userId).select((user) => user.value?.company!.id));
  if (companyId != null) {
    return ref.watch(companyProvider(companyId));
  }
});