Discuss: Minimize Observable interface into...

[matanlurey]

/// Represents an object with observable state or properties.
///
/// The interface does not require any specific technique to implement
/// observability. You may implement it in the following ways:
///
/// - Extend or mixin [ObservableChangeNotifier] or [ObservableStateNotifier]
/// - Implement the interface yourself and provide your own implementation
abstract class Observable<C extends ChangeRecord> {
  /// Emits a list of changes when the state of the object changes.
  ///
  /// Changes should produced in order, if significant.
  Stream<List<C>> get changes;
}

[natebosch]

+1 on having an interface designed for consumers rather than implementors. My first exposure to Observable (on both sides) had a steep learning curve because of the large surface area.

I'm less sure about the consequences of making it generic. Should we separate those discussions?

[jmesserly]

love it!

[matanlurey]

Sure we can split into sub-issues.

Intended generic use:

abstract class ObservableList<T> implements List<T>, Observable<ListChangeRecord<T>>> {}

Instead of the current:

abstract class ObservableList<T> implements Observable {
  // Let us be honest, if you are listening to an observable list, you want this one.
  Stream<List<ListChangeRecord<T>> get listChanges;
}

[natebosch]

You've convinced me on the generic argument as well 😃

[matanlurey]

I'm closing based on this already being underway.

[jmesserly]

YAY!

[jonaird]

I'm closing based on this already being underway.

Underway?

[markegli]

Reopening and assigning to myself since these changes were reverted in 0.21.0 when the package was migrated to Dart 2.