A java enabled website on a disk
Original article date: February 2001
Last week I received a CD across my desk. I haven’t really played with it yet, but if it contains what it says it contains, it deserves a serious mention. At first glance it looked like just another in a long line of catalogue CDs (or coasters, as I tend to refer to them), but this one was different because, quite simply, the company had put a java enabled website on a disk.
Why is that so cool? Well, a basic web site can consist of simply text files, pictures and perhaps sound, and the files that make up this website are created and simply placed on a webserver in the appropriate location and directory structure. But for more interactive sites, there are three different levels of ‘programming’ that can add functionality to a page.
Firstly, there is scripting, such as Javascript. This typically allows a single page to handle data input in a sophisticated fashion before the next page is loaded. You might, for example, have an address filling form which says ‘Select country’, and if you choose ‘US’ then the next question will read ‘Select State’, whereas if you select ‘UK’ for the first question, the next will read ‘Select county’ instead. Scripts are interpreted by the browser on the user’s computer as the page is displayed.
The next level of sophistication is the Java applet. These load at the same time as the web page but they are actual programs which your browser starts executing after the page is loaded. These can be very sophisticated, offering a high level of interaction. The downside with one of these is that it may take a bit of time to download in the first place, although many successful applets are not much bigger (in file size) than a typical web picture so it shouldn’t be a huge ordeal. You know when a web page includes an applet because before the applet is loaded you see a grey rectangle in the space where the applet will run when it loads. Big complex applets are not really all that widely used because of the download penalty – First Direct’s first stab at online banking involved downloading upwards of 500K of applet before anything happened, and I for one lost patience!
But like all Java, applets are platform independent. So whether you’re using Internet Explorer or Netscape Navigator, using Windows, Linux, Unix or a Mac, the same applets work fine.
The third level of sophistication is server side programming. This means that programs run on the machine that is serving the web pages, creating the pages you see on the fly. For example, you fill in a form, and when you submit the form the server runs a program using the form as input and creates a results page from the program’s output, which is the page you see next on your browser. It is irrelevant to you, the user, what platform these server side programs run on, or what language they are written in, because they don’t run on your computer. You submit a question, the next page you see is the answer, and the bit in between happens elsewhere.
Now, why is this CD I was talking about so cool? Well, it basically contains a website full of applets. And because I’ll be ’surfing’ my CD drive rather than the internet, they can be quite large sophisticated applets, that do whatever is needed to help me specify and select products. Pulling applet files off a CD is a lot faster than getting them by modem! All the hard work is done by my web browser. And there is no need to install anything on my computer – and I hate clogging my PC with rubbish. It is ready to use instantly. And what is more, the CD works whatever my platform. The manufacturer who sent it could even (if it so desired) copy the whole CD to a basic webserver and make the same thing available over the web, although admittedly the applets might make it a slow site.
So, suppliers, if you’re thinking of making a CD-Rom, and you wonder if your customers are Mac, Win or Unix users, try this route. On the other hand, if you instead want to produce something I’ll slag off incessantly, I suggest you make a Windows program that installs 20 MB of buggy rubbish onto my precious hard disk.
February 2001