javascript - resolving a promise with EventListener

Question

I am working on a popup div and I would like to have a promise attached to the animation so I can do something after the popup ended.

My approach does not work because I could not find a way to pass the promise to the function on the event handler. Seems you cannot use bind here. I have tried and although I can resolve the promise, I cannot remove the event handler

What would be a different solution here?

function EventListenerForPopUp() {
    this.removeEventListener("animationend", EventListenerForPopUp );
    this.Show.resolve();
}   

function ShowHideDiv() {        
    this.Show = function () { 
        return new Promise(function(resolve, reject) {
            this.Div.addEventListener("animationend", EventListenerForPopUp, false);
        }.bind(this));
    }
}

Answer 1

You do not need to pass the promise to the event handler, you need to pass the resolve callback:

function EventListenerForPopUp(resolve) {
            this.removeEventListener("animationend", EventListenerForPopUp );
            resolve();
}   

// [...]

        return new Promise(function(resolve, reject) {
            this.Div.addEventListener("animationend", function() {
                EventListenerForPopUp.call(this, resolve);
            }, false);

This looks a bit ugly to me, maybe you can look at something like this:

var div = this.Div;
return new Promise(function (resolve) {
    div.addEventListener("animationend", function animationendListener() {
        div.removeEventListener("animationend", animationendListener);
        //call any handler you want here, if needed
        resolve();
    });
});