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This is one point where I agree strongly with the name AJAX – remember what that first letter stands for To grasp why, its worth seeing some examples and discussing which Ive attmpted before here. In essence, when you make a synchronous call with XMLHttpRequest, everything else stops and waits for the request to complete. And that means everything – even any intervals youve set. You cant even abort() the request via the readyStateChange property (dont believe me? try and watch a [browser dependent] crash). In other words submitting a synchronous request puts you at the mercy of the...

Something I find strange about Javascript; [code lang=javascript] function Foo(){}; Foo.prototype = { bar: [], // or new Array() or new Object() set: function(val) { this.bar.push(val); }, displayBar: function() { alert (this.bar); } } var foo = new Foo(); foo.set(1); foo.set(2); // Alert displays 1,2 foo.displayBar(); // Destoy the object foo = null; // Create a new one var x = new Foo(); // What does this display? x.displayBar(); [/code] By declaring the bar property to be an Array, it seems to make it static to values assigned to the array are in effect updating the class definition –...

If youve read any of the posts Ive been dumping here, youll know Im critical of the way AJAX is frequently being used on the grounds that the network / server (and their inherant instability) arent being considered. Specifically have the feeling alot of AJAX development is happening @localhost so these problems simply arent showing up. Enter AJAX Proxy, which is meant as a tool to simulate network / server delays by sitting between your browser and your web server and delaying things. The first version is up here and currently in very hacky form. Its based on HTTP Debugging Proxy which in turn...

I think there are a lot of people like you work a lot in code instead of design mode, for those in my situation, following a little tip to hide our big div that we create. It will allow us to see the code a little clear and more easy to work, and of course, it can display the div again if you wish, here the code to add between . function hide(link){ var objet = document.getElementById(popup); // entre les deux tu mes le nom du div que tu veux faire apparatre ! if(objet.style.display == none || !objet.style.display){ objet.innerHTML = Ici le text que tu veux faire apparatre !; objet.style.disp...

Figured Id jump in on this blog, as Ive got itches to scratch. A toolkit for hooking up PHP and Javascript via XMLHttpRequest. The ideas behind JPSpan were originally conceived back in April 2004, as blogged here and the first release announced in September 2004, albeit under a different name. So while I dont have the same stomping rights as Brent Ashley, author or JSRS, figure Im a pre-Ajaxian, with mixed feelings about the hype surrounding the term, although JPSpan itself more or less fits into Jesse Rudermans definition or AJAX. Thats not to say Im going to get stuck on whether the term or ...

As I mentioned here, my concern about the buzz surrounding AJAX is not whats being said but what isnt being said. One question Ive got nagging me, which Ive yet to see serious discussion of, is the that of AJAX and sessions / state. I guess either no one is thinking about it or its got brushed under the carpet of implementation detail. The furthest Ive seen seen the discussion go in this direction is Diego blogging on ajax. That said Joshua Eichorn did a great job of hinting at the issues with his memento demo – move the pictures around then hit your browsers reload. From where I stand A...

AJAX stands for Asynchronous JavaScript And XML. Any server side technology that supports JavaScript also supports AJAX. AJAX is a browser technology, and is therefore independent of web server platforms. In this article we will learn about what AJAX is, how it works, and how can we use AJAX with PHP. Please remember, AJAX is not a programming language, so you dont have to learn any new technology. AJAX can be implemented by using existing standards (JavaScript and XML) in a different way. If we are using PHP or any server side technology and need to extract data from storage on a server (eg a...

One of the most important challenges web application developers face is the requirement for a fast and responsive user interface. AJAX was primary designed and developed with the intent of providing a fast and responsive user interface to address these challenges. According to Enrich Peterson, AJAX-enabled pages provide a slick, responsive user experience, making web-based applications function more like desktop-based ones. This article guides the reader through this new technology, its features, benefits and applicability in web application development. This is the first in the series of arti...

Please Choose a Person Choose Someone Bob Smith Janet Jones As you can see, we have a simple form with a select, from which to choose a person. Again, we are providing a fallback action for the form, in case our JavaScript cannot run. Below the form, we have a simple pre element that will be displaying the address information from the database. And now for the JavaScript. Basically, we will be commandeering the select and using its onchange event handler to trigger an XMLHttpRequest() call to obtain the address information for the selected individual. The server will be returning this info...

The start of 2005 saw the rise of a relatively new technology, dubbed Ajax by Jesse James Garrett of Adaptive Path. Ajax stands for Asynchronous JavaScript and XML. In a nutshell, it is the use of the nonstandard XMLHttpRequest() object to communicate with server-side scripts. It can send as well as receive information in a variety of formats, including XML, HTML, and even text files. Ajaxs most appealing characteristic, however, is its asynchronous nature, which means it can do all of this without having to refresh the page. This allows you to update portions of a page based upon user events ...