What is Ajax?

[Andy]

I just discovered what Ajax is.

It is a way to combine PHP and Javascript so you can serve up dynamic content to your webpage that comes from your web server. Normally, you ask a visitor to enter information into a form and click on a submit button. Then you display a complete new page with the new information. But Ajax allows you to update content without refreshing the whole page content and avoiding the use of the submit button.

To implement Ajax you just need a php enabled web host and your visitors need to be using a modern browser that supports the client-side functionality. But that should not be a problem since the latest browsers are but a free click away.

At least, this is my basic understanding after a quick read of this tutorial: http://www.tizag.com/ajaxTutorial/index.php

After I cut and pasted their example code it worked as stated on the tin, so no complaints from me 

[Andy]

Wow this is incredible technology! I am really into the concept of sharing resources between a web server and the client (your) browser.

You let people run complex sofware by simply browsing your site with no need for any browser plugins and they interact with your server-based data. The page does not completely reload like it does with the traditional submit button.

Here is a webcast showing off this technology: http://media.tibco.com/gi/gi32_webcast/index.html - this is over my head even though I am an experienced programmer but it does demonstrate how quickly a professional-looking web-based application can be developed when you are used to the tools at hand.

Luckily, the tutorial in the download is very easy to follow. It implements a form for looking up somebodies location in the US from their zip code.

I downloaded the software and worked through the first tutorial in Firefox. Post here if you have any problems getting it working. I missed a few things that you may get stuck with too such as using a local path to the starting web page and needing to download some plugin to support the debugging feature.

Get the software from: http://www.tibco.com/devnet/gi/product_resources33.jsp?tab=downloads - it's a free download as long as you don't need support.

[Andy]

I spent a few hours today working with the Tibco tool and learnt alot. But I don't see myself using it much since it makes heavy use of JavaScript which is hard to code with since you don't get the power of modern offline Integrated Development Environments (IDEs). This is important if you are designing/developing applications since you want to nail bugs as quickly as possible and have lightning fast development tools at you disposal.

The Tibco software is cool but when you have to type in Javascript code mostly by hand it is a bit off putting. However, they do have pre-written solutions to work from. So if you want to present web pages containing charts such as graphs and pie charts plus spreadsheet like information that your users can interact with, it is a very good solution. And you can interact with other web services such as post code look-up and maybe maps etc. The buzz word behind this is SOAP.

I also found out about DOM which is a way to interact with all the elements on a web page via JavaScript. What I really wanted to do was open an XML data file, get some user input and save the modified data back to the server. Unfortunately, I don't think it's possible to do this without using php or another server-side scripting language. I only managed to open data files. Not save them.