How to Remove Event Listeners Added with the bind() Method in JavaScript?

Removing Event Listeners Added with Bind()

Question:

In JavaScript, how can we effectively remove event listeners added using the bind() method?

Introduction:

The bind() method allows you to create a new function with a specified context, binding the this keyword to a particular object. This is commonly used to ensure that methods called by event listeners have access to the correct context.

Example:

Consider the following scenario:

(function () {
    // MyClass constructor
    MyClass = function () {
        this.myButton = document.getElementById("myButtonID");
        this.myButton.addEventListener(
            "click",
            this.clickListener.bind(this)
        );
    };

    MyClass.prototype.clickListener = function (event) {
        console.log(this); // Should be MyClass
    };

    // Method to disable the button
    MyClass.prototype.disableButton = function () {
        // Remove the event listener
        this.myButton.removeEventListener(
            "click",
            this.clickListener_________// Placeholder for missing argument
        );
    };
})();

Discussion:

One possible solution is to keep track of every listener added with bind(), but this approach is cumbersome and error-prone.

Optimal Solution:

A more efficient solution is to recognize that the bind() method creates a new function reference. Therefore, to remove the listener, we need to assign the reference to a variable:

const clickListenerBound = this.clickListener.bind(this);
this.myButton.addEventListener("click", clickListenerBound);

Then, when disabling the button:

this.myButton.removeEventListener("click", clickListenerBound);

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