Ability to remove listeners in UDP

[tanishqmanuja]

Component name

udp

Link to component documentation on our website

https://esphome.io/components/udp/

Describe the enhancement

Reverse method for any of the below would do this trick.

  void set_should_listen() { this->should_listen_ = true; }
  void add_listener(std::function<void(std::vector<uint8_t> &)> &&listener) {
    this->packet_listeners_.add(std::move(listener));
  }

Use cases

I am using udp compoenent to listen for DDP packet in an effect but when i stop the effect there should be an option to unlisten to save extra function calls when effect is not active but ddp packets are being sent from the ddp server.

Anything else?

Minimal Code: esphome/esphome@dev...tanishqmanuja:esphome:poc/ddp

[github-actions[bot]]

🏷️ I've automatically added the component: udp label to help categorize this feature request.

[clydebarrow]

Sure thing, wanna raise a PR?

[tanishqmanuja]

Reversing should_listen should be easy but i dont know about the other one since there needs to be key/hash/id in order to remove a listener this would mean breaking the signature add listener has. Any idea how to achieve this properly?

[clydebarrow]

Yes, it would require some jiggery-pokery to actually remove a listener, and that wouldn't stop the component itself listening.

I'd suggest just reworking the should_listen() setter to take a bool argument (default to true will be non-breaking).

The loop() code already checks that flag, but if off it should disable the loop. The setter should re-enable the loop if setting true.

[clydebarrow]

It still won't close the socket, but that's probably better than closing and reopening.

[clydebarrow]

I made the changes in a related PR so set_should_listen() takes a bool. It should do what you want.

esphome/esphome#13537

[tanishqmanuja]

Thanks, this will work fine for my use case 😁

[clydebarrow]

It will move to a different PR at some point, and then eventually get merged, but you can keep using it with the referenced PR as an external component for now.