Mind.random()

This is a site hosted by Google for educators.  As of today, Ajax and Distributed computing tutorials are available.

This year and the last saw a lot of the so-called proprietary  companies open sourcing a huge chunk of code, either as GPL, BSD or their own EULA.  Sun had the most impressive stats on this.  Fine.

I have been developing J2EE web applications for quite a number of years now and last year, like everybody, i was caught up with this Ajax fever. In a couple of projects, I “created” certain places for plugging in Ajax.  I am not a Javascript expert but I was really amazed at how some of the Ajax frameworks made my job so easy. DOJO nearly killed me last December. Ajax is good. But then delving deeper, it is still Javascript.  Security is an issue but the issue that bugged me was the scope for a lot of bugs. Cross-browser compatibility issues. And certain things dont work at all in IE. Or Firefox.

But then Adobe Flex came up and caught everyone’s attention.  I really used to feel jealous about those Flash based sites. It took a little time to download the application but post-download,  it was just magic.  And the idea of “programming” flash made me really happy.  I eventually joined the “Flex is the future” bandwagon.

I am still a fan of Flex. But then there was something else that was conflicting in my Flex interest. Its NOT open source. It is free. Fine. But it is still proprietory.  Just like a few states in the US and those Russian schools which shunned Microsoft, it is not at all good for the future to get bound to a bunch of coders. I can see from the flexibility and the power of Flex that Adobe has invested a huge sum towards this project. But then, what is the guarantee that Adobe wouldnt be closing down this entire project just because it didnt pay off well?  And in a few months, comes the Mozilla 3.0 (I really like the “Who needs a server when you have a browser” concept). You will have the power to run interactive web applications offline.  And if you really intend to stick on to the “Flash” part of Flex, try Open Laszlo and the wonderful demo page it gives.  Flex can do more. But Laszlo is open source. People at Laszlo say that their “current output format” is Flash. And they are planning DHTML too. (Next GWT?). And then what other format? (the power of community there !!!)

Adobe should realise that making a software free isnt going to gain wide acceptance and community support.  Developers are more and more conscious and careful in their selection of technologies. I have, a few times, convinced my manager into adopting open source alternatives than going for proprietory software (Not for the cost it involves)/free software. Free software sounds “Free suspicion” too. GPL is just too hot to refuse. If not GPL, BSD is fine. Adobe can market that “premium Flex” if they wanted to.  Java was hot. But GPL gave a “second life” to Java. Why did Sun open source its most secure Unix Operating system? Why are more and more giants looking for community support?

Its not that Adobe needs to be taught on this. They already know this. The question is “Are they reaching the right ears?”

Most of you must be knowing this site. But I really dont know how I missed this site till today.  If you are a “reader” of feeds and a Web 2.0 addict, you will find this site crazy to the core.

http://www.netvibes.com/

When it comes to Ajax what are the most common things you do?

1)  Avoid browser cache for GET requests.  

2) Hit the server wit that ’special’ javascript and populate single/multiple div tags.

3)  Get data as XML/JSON and parse the data  to populate the html page

4) Populate the data in a new Tab instead of a div.

If you really want to know the top 5 patterns that any AJAX user would be falling under (along with code snippets), here is the page from ibm.com.

Internet Explorer and a few other browsers cache GET requests for faster browsing.  Good for normal pages. Bad for AJAX. So, for repeated AJAX requests, you will get a cached data instead of the actual response from the server-side.  (Firefox, the prince of browsers does not seem to have this problem).

Two Options come up for this problem.

1) Use POST method for AJAX requests or

2) Just append some dummy parameter which has a different value for different GET requests. Just gives the browser an impression that its a fresh request.

So, Instead of this

var url = ‘getProducts.jsp?productId=123′

use this:

var url = ‘getProducts.jsp?productId=123′  + “&dummy=” + new Date().getTime();

This is one awesome site I recently bumped into. Has so much of handly DHTML scripts that is ready to use. Most of them are AJAX based. Just download and plugin to your project.

As we all know, Java applets were just like the lightning, came in a flash, filled us with amazement and disappeared in the same speed it came in.  Just like Steve Jobs, people were thinking about Java as “the heavyweight ball and chain”.  Java, on the client side was heavy, with the need to download the entire applet before running it.  And you will be needing a JRE and a browser plugin to run that applet both of which are not lightweight. That was thought of as the end of Java UI in the internet when the JEE framework came up. And the applets were soon forgotten. Still lot of web applications across the internet use applets but they are a countable number.  The death of applets also saw the death of feature Rich Internet Applications (RIAs).

Then came AJAX two years back. (AJAX, the name,  saw its second birthday last week). Same hype as applets.  Everybody were talking AJAX. AJAX is now seen as the future of the web. People have already drawn graphs showing AJAX as the only technology that is going to dominate the web for the next 5 years. But then digging deep, what is AJAX?  Just javascript with those bells and whistles.  And theoretically, everybody knows that AJAX was there for the Internet Explorer long before it came for other browsers in the form of ActiveXObject.  Till now, AJAX browser requests is done differently for different browsers, specifically Internet Explorer and others. Though lots of frameworks like the Prototype, DOJO and scriptaculous are already in the market which hides the cross-scripting mechanism, the weaknesses and the limitations of Javascript could not be hidden for long.  If you are a regular user of any of the AJAX based web-applications you would easily realise that the page is not foolproof. Only thing is that you are starting to live with it.  Initially, I used to have problems using Gmail with Internet Explorer. I can never click on any of those “links”  in Gmail after I download a mail-attached file. Only a browser refresh would help and you know pretty well that a browser refresh in Gmail would take me to the first page in my inbox and not the page i was working on.  And AJAX based web applications can never do all the things than an Applet can do.

But, as Bruce Eckel, author of Thinking in Java, rightly quotes, “Java has been around for 10 years and applets are not the primary way that we interact with the web”.  Applets is not the future.  I had to meekly accept that Java, even after 10 years, didnt have anything that could revolutionize the UI.  IBM came up with SWT for Desktop applications.  Eclipse rocks with SWT. True. But that is definitely not cross-platform. Netbeans is based on Swing. Cross-platform but heavy as hell.

So, what holds for the future. No Applets. No AJAX. What else?

http://www.youbackitup.com/

This site really drove me crazy. AJAX based drag and drop and then upload is completely taken care by Java. The centre “Drop your files here” is nothing but an Java applet. Just View source it to see this….

<object type="application/x-java-applet;version=1.4.1"
                    width= "200" height= "200"  id="rup" name="rup">  <param name="archive" value="dndplus.jar">

             <param name="code" value="com.radinks.dnd.DNDAppletPlus">

After uploading you get a link for download. Just pass the URL to your friends and enjoy.

Here is a link of cool AJAX driven dictionary.  Sure you’ll love it.

http://www.123dictionar.ro/