Kamaelia.Util.FirstOnly

• component FirstOnly

• Pass on the first item only
  • Example Usage
  • Behaviour

Pass on the first item only

The first item sent to FirstOnly will be passed on. All other items are ignored.

Example Usage

Displaying the frame rate, just once, from video when it is decoded:

Pipeline( ...
          DiracDecoder(),
          FirstOnly(),
          SimpleDetupler("frame_rate"),
          ConsoleEchoer(),
        )

Behaviour

The first data item sent to FirstOnly's "inbox" inbox is immediately sent on out of its "outbox" outbox.

Any subsequent data sent to its "inbox" inbox is discarded.

If a producerFinished or shutdownMicroprocess message is received on the "control" inbox. It is immediately sent on out of the "signal" outbox and the component then immediately terminates.

---

Kamaelia.Util.FirstOnly.FirstOnly

class FirstOnly(Axon.Component.component)

FirstOnly() -> new FirstOnly component.

Passes on the first item sent to it, and discards everything else.

Inboxes

• control : Shutdown signalling
• inbox : Data items

Outboxes

• outbox : First data item received
• signal : Shutdown signalling

Methods defined here

main(self)

Main loop