JavaScript and JQuery: Interactive Front-End Web Development

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AJAX & JSON

Ajax is a technique for loading data into part of a page without having to refresh the entire page. The data is often sent in a format called JavaScript Object Notation (or JSON).

The ability to load new content into part of a page improves the user experience because the user does not have to wait for an entire page to load if only part of it is being updated. This has led to a rise in so-called single page web applications (web-based tools that feel more like software applications, even though they run in the browser). This chapter covers:

WHAT AJAX IS

Ajax allows you to request data from a server and load it without having to refresh the entire page.

DATA FORMATS

Servers typically send back HTML, XML, or JSON, so you will learn about these formats.

JQUERY & AJAX

jQuery makes it easier to create Ajax requests and process the data the server returns.

WHAT IS AJAX?

You may have seen Ajax used on many websites, even if you were not aware that it was being used.

Live search (or autocomplete) commonly uses Ajax. You may have seen it used on the Google website. When you type into the search bar on the home page, sometimes you will see results coming up before you have finished typing.

Sometimes when you are shopping online and add items to your shopping cart, it is updated ...