London Ajax Training Workshop
Javascript & DHTML
The workshop is ideal for intermediate and experienced web developers who have a good knowledge of HTML, CSS and JavaScript.
This workshop will explain the hows and whys of Ajax, illustrated with straightforward examples. Don't let the code put you off: the most important lessons to be learned are about concepts, not syntax.
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This workshop will explain the hows and whys of Ajax, illustrated with straightforward examples. Don't let the code put you off: the most important lessons to be learned are about concepts, not syntax.
- A quick refresher in JavaScript syntax
- Introducing the Document Object Model
- Explaining the XMLHttpRequest Object
- Using Hijax to ensure graceful degradation
DOM Scripting
JavaScript is the language through which Ajax works its magic. Using JavaScript to update the contents of a document, even after it has loaded, is central to the Ajax methodology. This kind of dynamic manipulation is made possible by the Document Object Model. Together, JavaScript and the DOM form the foundations upon which Ajax applications are built.
The workshop begins with an overview of DOM Scripting. You will learn how JavaScript can tap into the power of the DOM to create and update markup on the fly.
XMLHttpRequest
While DOM Scripting is a powerful technology in itself, its combination with the XMLHttpRequest object makes for a sea-change in our traditional view of websites.
Most interactivity on the Web involves sending data to a server, receiving a response and displaying that result to the user. This back-and-forth exchange invariably involves page refreshes within the browser. The XMLHttpRequest object removes this requirement. This remarkable object sits between the client and the server, passing requests between without the need for page refreshes.
Hijax
There s a right way and a wrong way to enhance web pages. The wrong way is to make a technology a requirement for using a website. The right way is to ensure that any enhancements degrade gracefully.
Just as with accessibility and usability, a little planning can go a long way when it comes to graceful degradation. Instead of creating a fully-fledged Ajax application and then attempting to retrofit it, it makes more sense to create a traditional series of page refreshes and then intercept, or hijack, those requests using Ajax.
