[feature request] once handler

[Andarist]

would u consider adding this or is it out of scope? Ive tried implementing it myself so I could send a PR, but my minifications skill are not that great ;)

best result i got was 214B which is exceeding ur goal

[tunnckoCore]

A lot of things and implementations were declined because that strict limit, so probably no.

You might be interested in https://github.com/tunnckocore/dush, which is around ~300-400b, with all needed things, and can have micro plugins. I needed .once and such things (like #12 "chaining" which you can remove with plugin), that's why it exists.

[rangermeier]

As reference for anyone looking for this functionality: It's possible to add a once method at runtime:

const emitter = mitt()
emitter.once = (type, handler) => {
    const wrappedHandler = (evt) => {
        handler(evt)
        emitter.off(type, wrappedHandler)
    }
    emitter.on(type, wrappedHandler)
}

[plehnen]

@rangermeier this will not work when you try to unregister the handler via .off() before it was called at least "once".
(e.g. if you open a dialogue and register the once handler, close it and unregister with off, and re-open and again register with once. Once the event is emitted, the handler will now be called twice!)