onData method

@useResult VoidCallback onData(void listener(T data))

Registers a listener (addListener) that will only be invoked for Data results.

Use the returned VoidCallback function to unsubscribe the listener (i.e. calls removeListener).

See also:

• onResult for a more general listener.

Implementation

@useResult
VoidCallback onData(void Function(T data) listener) => onResult((result) {
      if (result case final Data<T> data) listener(data.data);
    });