Hello, and welcome to our exciting exploration of JavaScript's advanced event handling! Today, we'll discover how to manage webpage events proficiently. Specifically, we will look at Event Bubbling
, stopPropagation
, Event Delegation
, and how to create and dispatch custom events.
Before we dive into these advanced topics, let's begin with a basic understanding of event handling in JavaScript.
In JavaScript, an event signals that something has happened on the webpage. This 'something' could be various user actions like a mouse click, movement of the mouse, pressing a key, etc., or it might be browser actions like page loading or a form submission.
Event handling
refers to the process of setting up a function (an event handler) that runs when an event occurs. Here is a simple example for illustration:
In this example, clicking the button element triggers the onclick
event, which runs the function to display an alert message.
Just like popping balloons at a 'party', Event Bubbling happens when an event propagates from an element up to its parent elements. Here's an example using a button nested inside a div:
