JavaScript and JQuery: Interactive Front-End Web Development

6

EVENTS

When you browse the web, your browser registers different types of events. It's the browser's way of saying, “Hey, this just happened.” Your script can then respond to these events.

Scripts often respond to these events by updating the content of the web page (via the Document Object Model) which makes the page feel more interactive. In this chapter, you will learn how:

INTERACTIONS CREATE EVENTS

Events occur when users click or tap on a link, hover or swipe over an element, type on the keyboard, resize the window, or when the page they requested has loaded.

EVENTS TRIGGER CODE

When an event occurs, or fires, it can be used to trigger a particular function. Different code can be triggered when users interact with different parts of the page.

CODE RESPONDS TO USERS

In the last chapter, you saw how the DOM can be used to update a page. The events can trigger the kinds of changes the DOM is capable of. This is how a web page reacts to users.

DIFFERENT EVENT TYPES

Here is a selection of the events that occur in the browser while you are browsing the web. Any of these events can be used to trigger a function in your JavaScript code.

UI EVENTS          Occur when a user interacts with the browser's user interface (UI) rather than the web page

EVENT	DESCRIPTION
load	Web page has finished loading
unload	Web page is unloading (usually because a new page was requested)
error ...