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Discussion on: Review. Event dispatcher based on the CustomEvent interface

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Replies for: What if I have multiple listeners for the same event? For instance, if five components want to listen to the USER_LOGIN event. If I remove one of...

 
shystruk profile image
Vasyl Stokolosa •

You may have multiple listeners, but when you want to remove them you will remove only the last.

TARGET.removeEventListener(eventName, EVENTS[eventName]);

Good point here. Should think about that.

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theoutlander profile image
Nick Karnik • • Edited

Don't just remove the last added. The user needs complete control.

Usually, this is how I would expect it to be used:

let listener = () => {...}
obj.addEventListener('event', listener)
obj.removeEventListener('event', listener)

Another variation is:

let listenerHandler = obj.addEventListener('event', () => {...})
obj.removeEventListener('event', listenerHandler)

Simply calling this should remove all listeners:

obj.removeEventListener('event')
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shystruk profile image
Vasyl Stokolosa •

removeEventListener required a handler
developer.mozilla.org/en-US/docs/W...
so, you have to call remove for all listeners and pass the handler function