The Current State of Ajax

Dion Hinchcliffe writes "Ajax hasn't even been big a year yet and already open source development tools by the dozen are pouring out. Not to mention big names like TIBCO and Microsoft already have previews on the way of full-fledged IDEs for developing Ajax applications. Ajax may be the biggest software development story of 2005. Dion Hinchcliffe has a detailed article about how Ajax has evolved over the last six months and assesses the current state of tools, libraries, and mindshare. He also points out that Ajax will inadvertently end up being a driving force for Service-Oriented Architecture (SOA) for many organizations since it requires high performance back-end XML services."

Comments

More than a year thanks

[buro9]

"Ajax hasn't even been around a year yet"

Which is strange, because in 1999 I was making web applications that utilised hidden frames to post information to the server and return JavaScript arrays which I would then use to modify the limited parts of the DOM I had access to at that time. It worked in Netscape 3, Netscape 4, and IE 3 and IE 4.

So the techniques in question have been around for ages, and the use of Xml and the XmlHttp objects appeared several years ago with Outlook Web Access.

The ONLY thing that has been around for approx' a year is the utterly stupid name for it, "AJAX".

I'm glad other people are picking up on it and using it, it's very powerful, but let's not credit Adaptive Path with creating a technology or method that many people have been using for a long time.

If you have to use a name, then RIA (Rich Interactive Applications) is far more suitable and doesn't restrict the developer to asynchronous work only for it to be included in that.

Since it's Slashdotted...

[tcopeland]

...here's an article by Curt Hibbs on Ajax with Rails. He's got an "Ajax in 60 seconds" history lesson at the top of the article...

Re:Wow

[TopSpin]

Slashdotted by the second comment.

Doubt it. More like they saw the "mysterious future" post themselves and the subscribers hitting their machine before the post appeared before all ./. Some admin with enough wit to handle the situation frobbed the server and saved himself a tough Friday afternoon.

Comment removed

[account_deleted]

Comment removed based on user account deletion

What is it? Its this

[razmaspaz]

http://en.wikipedia.org/wiki/AJAX

Ajax is using Javascript to fetch only part of a web page and then updating the page with DHTML and JavaScript, reducing round trip time and server load and making the application "feel " more native.

qooxdoo

[The Bungi]

http://qooxdoo.sourceforge.net/

Weird name, but very impressive. Though not an "AJAX" framework, with some effort it can be "bound" to an OOB request factory or something similar to have your cake and eat it (rich client-side stuff + backend server). Very cool. And it works with IE and FF, but obviously better with Firefox.

BTW, I love how this "AJAX" thing is just a cute name for a Microsoft technology that was first introduced with IE4. The first "AJAX" app was the Exchange OWA client.

Re:What is it?

[Metaphorically]

Ajax is a buzz-word for Asynchronous JavaScript and XML. It generally refers to web based applications that feel more responsive than traditional pages because they don't refresh the whole page every time the user does an action. There's plenty more on Wikipedia.

Once you get down to the brass tacks of writing an app, here's a good way to deal with implementation problems people run in to.

i stopped reading here:

[circletimessquare]

"Ajax hasn't even been around a year yet"

excuse me?

ajax the functionality has been around for 6 years or more

the buzzword "ajax" and the google maps implementation that skyrocketed the word to buzzword status has only been around for less than a year

i'm usually not one to champion geek snobbery

but when geek snobbery is pitted against cattle herds of phbs spouting buzzwords with little understanding of the buzzword itself, geek snobbery is more appealing

Re:What is it?

[AKAImBatman]

JavaScript. Please don't confuse Java with JavaScript. It just makes everyone's lives harder. (Especially when managers hire the new "Java" expert.) :-/

Re:High Performance Back-end Services

[Anonymous Coward]

Dion Hinchcliffe's Blog - Musings and Ruminations on Building Great Systems

Agility, Service-Orientation, Enterprise Architecture, and Software Development
State of Ajax: Progress, Challenges, and Implications for SOAs
A lot of bits have been pushed around the blogosphere on the topic of Ajax over the last few months. This includes my own post back in March, which gave a general overview of what Ajax was and what it does. A lot of exciting stuff has happened since then, and Ajax has rapidy matured into a development of major significance. Coverage has been all over the map and runs the gamut from Rasmus' been-there-done-that 30 second Ajax tutorial to Alex Bosworth's list of Ajax Mistakes to the uber-repository of Ajax knowedge, Ajax Matters.

Many of you already know that Ajax is a web client programming style which eschews traditional HTML web pages, which are only sprinkled lightly with JavaScript and reload pretty much every time they are updated or clicked on. Instead, an Ajax web client receives an Ajax JavaScript library into a hidden frame which provides run-time visuals on the main browser window that look and feel very much like a native application. Ajax web clients, once loaded, communicate with XML services on the back end (via a browser's built-in powerful XMLHttpRequest API), and then use JavaScript to manipulate what the users sees programmatically via DHTML.

All of this allows Ajax to provide a compelling user experience because 1) it doesn't reload the web page, and 2) it runs asynchronously allowing background server-side requests for information to be issued, all while the users clicks, types, and otherwise interacts with the application in the foreground. Google Maps is the pre-eminent example of a modern Ajax application: rich, interactive, easy-to-use, and predictive in that it loads the map tiles that are just offscreen in case you need them. This is all very good for web client client development, but why all the attention across the board?

Figure 1: Ajax: The first compelling new client application model since the modern web browser

Because Ajax is a sincerely compelling synthesis of the ubiquitous features found in the most popular Internet browsers is why. Practitioners of Ajax get high-intensity user interaction (end-user productivity), asynchronicity (efficient backround processing), web browser access to web services (web service access, reuse, and interoperability, as well as SOA integration), platform neutrality (browser and operating system agnosticity), and the Ajax feature set can be delivered as a framework you don't have to create yourself (developer productivity).

Individually, these items are very nice, but taken as a whole, working solution and you have something extremely special. While many folks thought the web browser story had stopped around the year 2000, Ajax takes us to a whole new place. Slashdot recently highlighted a notable new article in Wired that claims that the industry, mostly on the basis of Ajax, "has affirmed the viability of the web as a standalone software development platform."

This is no small thing, and has the potential to repave the modern application development landscape. Why? Because Ajax creates a rich and fertile new space for developing software solutions that can reach almost anyone, anywhere whatever they're browsing with. It doesn't require anything more specific than your local browser, is based on standards, and leverages all the services that most organizations have in place in their back office, especially if they have been building service-oriented architectures.

Of course, there are some problems with Ajax, as there inevitably are with any major new approach. One is testing. You not only still have to test your applications, but even more thoroughly. Given that JavaScript, DHTML, XmlHttpRequest, and DOM support all vary slightly between browsers, you need to test your Ajax applications in all supported browser versions and in multiple screen resolutions to make sure you have

Just developed 2 large AJAX-enabled apps

[mflorell]

I just finished about 4 months of work writing two AJAX apps using PHP with javascript and while the end result is what we were hoping for and the app runs beautifully, it took me a tremendous amount of time to code it as compared to a standard fat-GUI-app that runs on the client machine.

I basically did a port of the functionality I had in two Perl/TK apps, but I wanted portability and easy updates of code and I had just done a stress test of AJAX in Firefox and IE and they both seemed to handle the load OK so I started developing.

I did not use any tools aside from a text editor and the browsers to test in. The tools like SAJAX just created bloated code that crashed the browsers once things got too complex for them so I decided just to hand-code it from there on. I built in some session security and user authentication both of which ended up working rather well.

These apps are querying other pages to get updates on phone system extensions statuses(from Asterisk) and other bits of information and updating DHTML elements constantly, so they do generate a lot of HTTP requests and use at least three times of the bandwidth that the fat-client perl/Tk app used to, but the database and web server seem to take the traffic OK and we thought that both of the browsers did too until we did some time tests.

We were able to leave the AJAX app running in the same Firefox session for over 2 weeks before we had to reboot the machine for other reasons which was wonderful and much longer than we thought. But, Internet Explorer never lasted a day. It seems that in the ActiveX element that handles XML requests(IE itself doesn't do it internally like Firefox does) there is a memory leak and within 2 hours our app was chewing up over 120MB of RAM and was getting slower. We tried several fixes and the only way to get the memory back was to kill the iexplore.exe process(This was on IE5.0 through 6.1). And that is the reason we recommend only Firefox for intensive AJAX apps.

In case anyone has read this far, the apps are GPLd and available on sourceforge. They are apps that extend the functionality of Asterisk PBX phone system extensions. You need to have Asterisk and the astGUIclient suite installed in order to test them:
astGUIclient project page

MATT---

Re:Just developed 2 large AJAX-enabled apps

[Osty]

But, Internet Explorer never lasted a day. It seems that in the ActiveX element that handles XML requests(IE itself doesn't do it internally like Firefox does) there is a memory leak and within 2 hours our app was chewing up over 120MB of RAM and was getting slower. We tried several fixes and the only way to get the memory back was to kill the iexplore.exe process(This was on IE5.0 through 6.1). And that is the reason we recommend only Firefox for intensive AJAX apps.

The leak is not with the XMLHTTP object, but with Javascript itself. You have to be very careful about DOM manipulation order to avoid circular references that can't be garbage collected, and you pretty need to avoid using closures entirely (which sucks because closures are damn cool). Make sure you clean up after yourself when pages unload (detach events and such), and as long as you're careful you should be fine.

IE's problem is that the DOM is not a pure javascript implementation. Each DOM object is a COM object, and Jscript's garbage collector doesn't handle COM objects properly. Thus, if you get into a circular reference (a node has an expando property that references a jscript method that references the node), the GC can't clean it up because it can't clear COM objects. So long as the node reference stays around, the jscript can't be cleaned up and you're leaking memory.

There's a lot more to it than that, and a lot of other scenarios that can cause leaks. More information, including suggested practices to avoid leaking as much as possible.

Hopefully IE7 will fix these memory leaks, but I wouldn't hold my breath waiting.

Re:Ajax compared to Flash

[temi]

Here it is, and while it is the ONLY difference it is a HUGE difference and one that is big enough to make vendors know to switch to AJAX.

AJAX will work with nearly any major browser off the shelf. poof. No downloading plug-ins once or twice based on how many browsers you are using, no nothing. Just come to the site and begin using the application.

With FLASH, you must download a plug-in. That may not sound like a lot but it is huge. It is at least one barrier for customers (who are by and large tech-retarded) to overcome just to use a vendor's service. And if there are multiple browsers there will be multiple plug-in downloads and there are times when the plug-ins wont work.

So bottom line is, by taking out the need for customers to visit a 3rd party, the User experience is exponentially increased and brand brainwashing commences immediately and without any hiccups. Believe me, no one wants to ever expose 3rd party tools when they are trying to sell something.

Re:What is it?

[afidel]

Why do people still call it Javascript? The correct term for the modern language is ECMAScript, Javascript was the Netscape version built in colaboration with Sun and revised several times over the years. I doubt that much origional Javascript code would work well in modern browsers.

Re:Simple fix for cross-domain AJAX

[elemental23]

An even easier way would be to enable mod_proxy and add two lines to your Apache config:

ProxyPass /foo http://www.example.net/bar
ProxyPassReverse /foo http://www.example.net/bar

Where 'foo' is the apparent target URI on the current domain and 'http://www.example.net/bar' is the actual target URI.

Re:Thin Clients, Fat Pockets

[br0ck]

And doing it in an IFrame can get around one of the biggest disadvantages of XMLHTTPRequest, the broken browser back button. This is the method that Google Maps uses to be able to page back through search results. The Ajax Wikipidia article mentions this and other workarounds.

Re:Thin Clients, Fat Pockets

[yomahz]

I can speak as someone who has in fact done just that and would have killed for an XMLHttpRequest object back in 2001.

MS added XMLHttpRequest to IE4 around 1998-1999. You wouldn't have had to kill anyone.

http://en.wikipedia.org/wiki/AJAX