description

# capture method Null safety

StreamSubscription<T> capture (

1. void onData(
   1. T event
   )

)

Adds a capturing subscription to this stream.

If the target of the event is a descendant of the element from which this stream derives then `onData` is called before the event propagates down to the target. This is the opposite of bubbling behavior, where the event is first processed for the event target and then bubbles upward.

## Other resources

- Event Capture from the W3C DOM Events specification.

## Implementation

    StreamSubscription<T> capture(void onData(T event));