onLoading method

@useResult VoidCallback onLoading(void listener(T? data))

Registers a listener (addListener) that will only be invoked for Loading 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 onLoading(void Function(T? data) listener) => onResult((result) {
      if (result case final Loading<T> loading) listener(loading.data);
    });