flutter: Unhandled Exception: Bad state: Cannot add new events after calling close

Question

I am trying to use the bloc pattern to manage data from an API and show them in my widget. I am able to fetch data from API and process it and show it, but I am using a bott

Answer 1

Use StreamController.isClosed to check if the controller is closed or not, if not closed add data to it.

if (!_controller.isClosed) 
  _controller.sink.add(...); // safe to add data as _controller isn't closed yet

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From Docs:

Whether the stream controller is closed for adding more events.

The controller becomes closed by calling the close method. New events cannot be added, by calling add or addError, to a closed controller.

If the controller is closed, the "done" event might not have been delivered yet, but it has been scheduled, and it is too late to add more events.