description

# 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 element of the stream after this function is called. If `handleData` is `null`, further elements 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)?);