onData method Null safety

void onData (
  1. void handleData(
    1. T data
    )
)

Replaces the data event handler of this subscription.

The handleData function is called for each data event of the stream after this function is called. If handleData is null, data events are ignored.

This method replaces the current handler set by the invocation of Stream.listen or by a previous call to onData.

Implementation

void onData(void handleData(T data)?);