The blur
event fires when an element has lost focus. The main difference between this event and focusout
is that focusout
bubbles while blur
does not.
The opposite of blur
is focus
.
HTML
<form id="form">
<input type="text" placeholder="text input">
<input type="password" placeholder="password">
</form>
JavaScript
const password = document.querySelector('input[type="password"]');
password.addEventListener('focus', (event) => {
event.target.style.background = 'pink';
});
password.addEventListener('blur', (event) => {
event.target.style.background = '';
});
Result
There are two ways of implementing event delegation for this event: by using the focusout
event, or by setting the useCapture
parameter of addEventListener()
to true
.
HTML
<form id="form">
<input type="text" placeholder="text input">
<input type="password" placeholder="password">
</form>
JavaScript
const form = document.getElementById('form');
form.addEventListener('focus', (event) => {
event.target.style.background = 'pink';
}, true);
form.addEventListener('blur', (event) => {
event.target.style.background = '';
}, true);
Result
The value of Document.activeElement
varies across browsers while this event is being handled (bug 452307): IE10 sets it to the element that the focus will move to, while Firefox and Chrome often set it to the body
of the document.