Some code snippet to handle your messy API call states. ;) #EndSARS

omni_state.dart

class ApiState<T> {
  String message;
  T data;
  ApiStates state;

  ApiState(this.state, this.data, this.message);

  static ApiState<T> loading<T>() {
    return ApiState<T>(ApiStates.Loading, null, null);
  }

  static ApiState<T> success<T>(T data) {
    return ApiState<T>(ApiStates.Success, data, null);
  }

  static ApiState<T> error<T>(String error) {
    return ApiState<T>(ApiStates.Failed, null, error);
  }
}

enum ApiStates { Loading, Success, Failed }


// Usage in Model/Bloc class
final _intStreamController = StreamController<ApiState<int>>();
final get intStream => _intStreamController.stream;
_intStreamController.sink.add(ApiStatus.success(200)); // This is called when the API call is successful
_intStreamController.sink.add(ApiStatus.error("Some crazy error message")); //Called when an error occurs in the API
_intStreamController.sink.add(ApiStatus.loading()); //Data is currently loading

//Usage in your UI
YourBloc _yourBloc = new YourBloc();

//This should be added to the base class of your UI
extension<T> on AsyncSnapshot<ApiState<T>> {
  bool get isSuccess =>
      this.data != null && this.data.state == ApiStates.Success;
  bool get isLoading =>
      this.data != null && this.data.state == ApiStates.Loading;
  bool get hasFailed =>
      this.data != null && this.data.state == ApiStates.Failed;
  //This should be call only if `hasFailed` is true
  String get errorMessage => this.data.message;
  T get value => this.data.data;
}

//Now you can check the state in your stream builder.
    new StreamBuilder<ApiState<int>>(
    stream: _yourBloc.intStream
      builder: (context, snapshot) {
        return snapshot.isLoading
            ? Text("Its loading")
            : snapshot.hasFailed
                ? Text(snapshot.errorMessage ??
                    "It has failed like the Nigerian govt.")
                : Text("It's successful ${snapshot.value}");
      },
    );