Removing the event listener using JavaScript
Removing the event listener from a specific HTML element can be so important in some cases as you don’t want the event to get triggered multiple times without any reason. JavaScript can be very helpful to achieve this functionality so let’s see how we can easily get this job done.
RemoveEventListener() method
RemoveEventListener() is a built-in function in JavaScript that can be used to remove event listeners from HTML elements.Assume you have the following event listener attached to a <button> element:
<center>
<button id="click">Click me</button>
</center>
<script>
let btn = document.getElementById('click');
const clicked = (e) => {
alert('this button was clicked');
}
btn.addEventListener('click', clicked)
</script>
</body
Now suppose you want to remove the click event from the button, you’ll need a reference to both the element containing the listener and the callback function reference to remove an event listener effectively. To remove the “click” event, the code will go like this:
However, it’s not a good idea to pass an event listener an unnamed callback function like this:
alert('this button was clicked');
})
You won’t be able to remove the event listener without the callback function name, as seen in the example above.
Removing the event listener after clicking the button
Sometimes you may don’t want the button to be clicked twice as if its going to be clicked, the event will trigger and cause the processing issues under the event. So to handle this issue instantly we need to attach a removeEventListener() inside the addEvenetListener() method. Let’s see how we can achieve this functionality in the code below:
<center>
<button id="click">Click me</button>
</center>
<script>
let btn = document.getElementById('click');
const clicked = (e) => {
alert('this button was clicked');
btn.disabled=true; // this line is disabling the button
btn.removeEventListener('click', clicked) // this line removes the event listener right after clicking the button
}
btn.addEventListener('click', clicked)
</script>
</body>
Output:
So with the above example, once the button was clicked, it’s going to trigger the event attached to it and remove that event after disabling the button to avoid multiple clicks at the same time from the user.
That’s how you get rid of JavaScript event listeners from HTML elements. For removing an event listener from an HTML element, you need to take care of the two things, you have to define the type of the event and the second thing is that you need to provide the reference function that is attached to the event listener.
Conclusion
The removeEventListener() method is used whenever you are required to remove the event from a particular HTML element. This method requires two arguments,the first argument will be the event name while the second argument will be the function that is attached to the event listener. In this article, we have seen the example where we have discussed how we can simply remove an event attached to an HTML element.
from https://ift.tt/3F1yUk1
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