How does emitter work

The subscribe function takes the event name, in our example that will be event:name-changed and the function to call when someone emits or screaming the event. If no one already registers the event we need to do this at the first time by setting the key as the event name and initialize it with an empty array, then we push to this array the function that we want to execute when someone emits the event. If the event exists in our events map, we are looping over the functions that we register in the subscribe method and call them with the data.

But we still have one problem. So now we can call the unsubscribe function like this:. No spam, ever. Unsubscribe anytime. User Authentication is one of the common workflow in web applications.

In this t This Article explains everything about how to build Nodejs Microservices in clou One of the tragic accident in my job turned out to be good learning for me in re How does it work? Example: EventEmitter. EventEmitter Methods Description emitter. No checks are made to see if the listener has already been added. It can also be called as an alias of emitter. This listener is invoked only the next time the event is fired, after which it is removed.

Caution: changes array indices in the listener array behind the listener. Example: Return EventEmitter from a function. Example: Extend EventEmitter Class. Want to check how much you know Node. This event is emitted any time a listener is added.

When this event is triggered, the listener may not yet have been added to the array of listeners for the event. This event is emitted any time someone removes a listener. When this event is triggered, the listener may not yet have been removed from the array of listeners for the event.

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