AJAX Buzzword Reinvigorates Javascript 541
samuel4242 writes "Javascript may have been with us since the beginning of the browser, but it's going through a renaissance as companies like Google create Javascript-enabled tools like Google Maps . There's even a nice, newly coined acronym , AJAX for "Asynchronous Javascript and XML". A nice survey article from Infoworld interviews Javascript creator, Brendan Eich, who says that this is what he and Marc Andreessen planned from the beginning. Perhaps AJAX will finally deliver what Java promised. Perhaps it will really provide a solid way to distribute software seamlessly."
DAMNIT Java != Javascript (Score:1, Informative)
Rewriting history? (Score:5, Informative)
Huh? I don't seem to remember seeing it until about '96 or '97. That's just a wee bit later than the beginning of the browser...
Re:Rewriting history? (Score:3, Informative)
Ruby on Rails and AJAX (Score:2, Informative)
this is good, and here's more material (Score:5, Informative)
For me, the crux of the usefulness and eventual adoption and finally complete embracing of AJAX lies in the article's paragraph:
I've seen what Google has done with AJAX (e.g., Google suggest), and it's stuff I never imagined could be so repsonsive in a web context. For me it starts to make programming fun again, and web programming an acceptable form of application development.
When browsers and web first emerged I could see the writing on the wall, but I wasn't happy about it. Browser application writing from the programming perspective was probably the single most giant leap backwards in technology for me (not including technologies introduced by Microsoft)....: you mean, all the years I've spent honing skills writing applications no longer apply? You mean I no longer have "state" as a tool for maintaining sanity in my application???? Hwaahhh??? I have to do what to change the web page???
While there have been some technologies (ASP, JSP, etc) to help with these issues, none have addressed the responsiveness issue with the web page round trip message loop. AJAX comes close. Now all I have to do is learn it.
For a great example of the responsive nature of this (I've referenced this before), go to Google Personal Home [google.com], set up your own home page, and play... Configure your modules by dragging them around... open and close your g-mail previews. This all starts looking alot like programs actually running locally on your own machine. (I'm assuming all are familiar with and have played similarly with Google Maps [google.com].)
Additionally, here are some very good resources to learn more about AJAX:
That's it, I'm done.
Re:DAMNIT Java != Javascript (Score:2, Informative)
Re:Correct me if i'm wrong but... (Score:4, Informative)
Re:Correct me if i'm wrong but... (Score:2, Informative)
It works beautifully in all three.
Re:Slower than Java (Score:2, Informative)
Re:AJAX Won't Deliver... (Score:4, Informative)
AJAX's fate does not rest on all browsers being in full compliance to the standards, it rests more on the implementation of AJAX components. You can read more about my view on this on my blog [64.233.167.104].
Re:Ruby on Rails and AJAX (Score:2, Informative)
Re:Rewriting history? (Score:2, Informative)
Re:Rewriting history? (Score:2, Informative)
Re:widget set (Score:4, Informative)
Ajax mistakes (Score:5, Informative)
Re:Java (Score:3, Informative)
Okay, fine.
Java applets embedded in webpages are dead.
But on the other hand, J2EE is heading towards becoming the de facto standard language for server-side web development, as is J2ME for handheld development.
On the whole, Java is alive and well.
Re:Correct me if i'm wrong but... (Score:5, Informative)
Re:Javascript? (Score:5, Informative)
Actually, Javascript is surprisingly robust. Probably you're referring the platform inconsistencies, which have long been a showstopper. But with recent versions of browsers supporting the javascript standard (ie. ECMAScript) increasingly well, a lot of the major wholes are closing, and you really can write cross-platform javascript with a minimal compatibility layer.
Javascript is not meant to be a large-scale programming language... it doesn't have strong-typing or other features that you want when developing million-line applications. However, it is still an extremely powerful language providing things like full object-orientation (everything is secretly descended from the window object), comprehensive hooks to HTML, functions as data, regular expressions, flexible data access (eg. objects as hashes), and robust event handling.
I used to think of javascript as a toy language, but when you get to down to it, it does what it needs to do very cleanly and efficiently without imposing unnecessary overhead on the programmer.
Re:Ruby on Rails and AJAX (Score:5, Informative)
Standardization: Flash, Java, AJAX (Score:4, Informative)
One way is AJAX. To make it work well, you essentially have to write a version of the page for each major browser - which is a lot of work. Of course, there are development tools that make this substantially easier. It is by far the most seamlessly integrated with the BROWSING experience, but is less suited than Flash or Java for real applications - like a game or any other datadriven mouse-interactive thing. I don't believe there is no OOP Javascript in a browser.
Another way is Java applets. Java has the advantage that lots of programmers learn it to do nonapplet Java work. The big disadvantage is that a big part of the installed userbase has broken M$ Java engines, and it's generally impossible to install a Java engine without computer-admin privs (as opposed to "browser admin" privs)
The final way is Flash MX 2004 or Flex. Like Java applets, it is a fully featured OOP programming language (Actionscript) It expects to deal with server information, and can innately request data from mostly-arbitrary SOAP Web Services. It also works innately on OSX, Windows and i386 Linux in most all browsers and on a variety of small devices. It doesn't work on more obscure platforms, however, and it's not OSS so it can't be ported by just anybody.
Summary: If you want to a supercharged browser experience, use AJAX. If you want an application that "just happens" to be projected over the web, use Flash.
Re:Ajax Q&A... the real one (Score:5, Informative)
Re:Rewriting history? (Score:5, Informative)
But in Netscape 2, there were not very many hooks from JavaScript back into the HTML. You had a document object and a window object of course, but beyond that about the only "DHTML" you could do was mostly restricted to manipulating form values and popping open new windows. Useful, to be sure, but that was about it.
In Netscape 3 they added the document.images array, and that began the whole image-swapping madness that got everyone hooked on JavaScript, for better or worse.
And then in NS4/MSIE4 they added the competing, incompatible DOMs that got us into the hell years of DHTML. DHTML as a term arrived with the version 4 browsers.
Give JavaScript some credit for surviving its own history... the language has been through some very rough years, only to now finally get some credit for being a powerful web tool.
Re:widget set - Try Konfabulator (Score:3, Informative)
Re:Wake me up when JavaScript has error handling (Score:1, Informative)
Re:AJAX will also kick your ass (Score:5, Informative)
It's worth the price just for the $() function, which does a document.getElementById() on the argument
Re:AJAX also good for... (Score:5, Informative)
Seriously, being someone who actually has quite a bit of *real* experience with Ajax (though we were doing it before the term was coined) across multiple browsers, I can say that the ratio of comments which demonstrate the author understands the full implications of Ajax to those who are just spouting nonsense is about 1:75. I've never read an article on Slashdot before where so many comments missed the target, and I feel like I've been around Slashdot for a little while.
The idea behind Ajax *does* revolutionize the web paradigm. All this nonsense about cross browser compatability issues is just that: nonsense; it works in Mozilla, Firefox, IE, Opera, and Konqueror each on their respective available platforms. I've actually heard people talking about "Ajax enabled advertisements instead of Flash." Other gems like "Ajax doesn't do anything that a well programmed web application can't do," and "It's just needlessly complex web pages" only point to users who fail to grasp the fundamental concept.
Let me tell you: Ajax is FAST. You don't realize how unresponsive web pages are until you get to play with a web app that is always waiting on you, no the other way around. When I submit information, why do I need to wait for that information to get to the server before I can begin to perform another operation if that operation isn't dependant on the previous? Click Add To Cart then *immediately* start searching for the next item. Stuff like that.
The amount of data being exchanged is far less (if you do it RIGHT, you people who are talking about using the XMLHttpRequest.responseText property, this does NOT include you). Rather than reload an entire page with all the framework, you're loading only the portion of the page that changed.
Aside from piecemeal page loading, you also get to load only the relevant data. For example, rather than load a form, and all the form formatting to make the text fields line up correctly, and all the validation code to validate that form, you load a series of XML tags that contain only the basic information needed to tell the client how to lay out the form. The client takes care of generating the HTML for the form, and your form data looks more like this:
<input name="username" label="User Name" required="yes" minlength="5" maxlength="10"/>
versus
<tr class="lightRow"><td class="labelColumn"><label for="username">User Name:</label></td><td class="inputColumn"><input id="username" name="username" maxlength="10"></td></tr>
, then later form validation code.
Often times your data fits inside a single TCP packet.
I'll make this concession: yes, this is stuff that could be done before the Ajax philosophy using Flash or Java Applets. But both require a plugin, and one of them is even proprietary. Both have potential firewall issues, and neither will run on a vanilla Fedora Core build. Both require higher resource consumption for the user, and both lend to a feeling of sluggishness on the site for the user.
That's not to say that it's not without its dangers. Like all web apps, you can't trust the data from the client. Here the client gets a bit lower level access to the data. You still have to make sure that you're protecting yourself well against data poisoning attacks.
The thing I like most about this model though is this: It's truly a MVC (Model View Controller) framework.
The model is of course your server side logic scripts. The View is the browser (the server side logic scripts send back generically formatted data, the browser does all the display). The Controller is the combination of XMLHttpRequest object, and the processing management script on the server. It's very conceivable that you could write a new front end for your application by simply
Re:AJAX will also kick your ass (Score:3, Informative)
For example, click on the first link [microsoft.com] in your example. It takes you to "DHTML Collections". It lists "all" as a collection. "all" is not a DOM collection. It is MS specific crap that break compatibility between browsers and makes your web app only work in IE.
Here is a _real_ DOM reference [mozilla.org]. This one is standards compliant and will work with the major browsers out there.
Re:AJAX also good for... (Score:3, Informative)
Don't be ridiculous. Web Applications must depend upon a client side programming language. Web pages need not depend on a client side programming language. Applications have specific target platforms and requirements. Pages however are expected to be at least viewable on a much broader range of browser platforms.
Me thinks you're out of your depth.
Re:AJAX also good for... (Score:3, Informative)
The basic overview is that you have various
Only the portion of the page that needs to change actually changes, the user never reloads anything else. Because this happens asynchronously, multiple operations can happen in parallel and the user can continue to interact with the rest of the page while their operation performs in the background.
Imagine looking at a product listing on an ecommerce site. You can click "Add To Cart" next to each item on the page in rapid succession. You don't have to wait for each adding to successfully register, you click "Add" and it immediately appears in the shopping cart, with perhaps an indicator that the add is still taking place (italicise the text of the product name, for example, and unitalicize it when the add is done).
The reason why it's a paradigm shift is that this makes the web page behave much more like a desktop application, but it can be more responsive than some desktop apps I've seen which are not capable of parallel operations like this (while processing an action, no further actions can happen). The web developer works only with individual page parts, and they don't have to worry about what else should be displayed on the page. You've already sent data to the client about the user's personal information (login name, view preferences, and such), there's no need to re-send this the next time the user clicks on a link. You get to preserve the state of previous page hits.
There's no longer a model of pages, it's a functional model. Individual layouts happen as a page hit, everything else is a function call. That function returns raw data and the client lays it out. All formatting is client side, and this combined with the fact that you're only building the portions of pages that changed leads to greatly reduced server loads.
But most importantly of all, the user never ever waits on the server to respond unless they either need confirmation that the operation has happened, or they are depending on the results of that response for their next operation (eg, when you do a search for a given product, you have to wait for the server to give you that product listing before you can add it to your cart).
Re:AJAX also good for... (Score:3, Informative)
When you talk about "the web" being the platform, you're not talking about applications, you're talking about web pages with application-like usage patterns.
Only a fraction of applications built with the browser as the platform require that the most absolute cross-platform "everyone" be able to use them without out of the box.