AJAX is real easy

[DaveSawers]

After listening to all the hype, I decided to sit down the other day and learn how to use AJAX. Really, there's almost nothing to it. It's very easy to learn how to use although it's not always so obvious how to use it appropriately.

Anyway, from nowhere it took less than three hours for me to complete my first AJAX using application. I have some further details in my blog and my first AJAX application can be compared with the non AJAX implementation of the same application.

If you've been hesitating before diving in, don't be afraid, it's easy.

[speed]

But what about accessibility?

Last time I checked WAI-A asked that sites function without client side scripting, therefore the application needs to degrade gracefully when JS is not available.

For a simple application such as your units tool this isn't a real problem as you just need to add submit buttons, but for a more complex application it potentially increases the code you have to write as you have to support input with and without AJAX.

Even if we assume all browsers have JS on, then a dynamic update of text doesn't necessarily cause a screen reader to read the changed text again, leaving the user guessing as to what happened.

So while I agree AJAX can add to usability and isn't particularly hard to work with, I do think it needs to be used with care.

[kgun]

In reality, AJAX (Asynchronous JAvascrip + Xml), also called webapplications, is not a new technology. It can be misused as all other technologies. If you program for older browsers, you have to use feature and / or browser sniffing to go around the problem and it shall as said above, degrade gracefully if JS is not activated.

I have a post in the hidden part of my forum (ForumNorway.com) how you shall test for different browsers.

Note: There are a lot of technologies related to AJAX e.g. all Xtechnologies like XPath, XLink etc. It is not easy to get an overview (of the best). The place to search is W3C and follow what is being published there.

I see that you use math in your AJAX application. There is of course an Xtechnology, XMath.

KW searh: XMath

74800 hits.

[DaveSawers]

Originally Posted by speed

But what about accessibility?

...

Even if we assume all browsers have JS on, then a dynamic update of text doesn't necessarily cause a screen reader to read the changed text again, leaving the user guessing as to what happened...

The standards perhaps need to catch up with reality on this kind of technology so that producers of screen readers are encouraged to take dynamic features into account.

Like kgun, I believe more dynamism in web sites is the way things are going.

JavaScript is perhaps the least dangerous client side scripting available and there really is no reason why it shouldn't always be turned on in browsers. Conesquently, I have no intention of producing a JavaScript free version of my little app.

[kgun]

Accessibility and usability, not least for mobile devices:

Next step, make your AJAX (web) application ready for mobile devices. Web applications for mobile devices are for the future, and you learn how to make websites for those tools as soon as possible in 2007.

Related links:
HTML and CSS for Mobiles

.NET Mobile Devices

CSS Mobile Profile 2.0

The Mobile Web, Simplified

Getting Started with the XHTML Mobile Profile

Mobile Web Site Guidelines

Want to write CSS for a handheld?

"Abstract Web applications, often referred to as AJAX, are increasing in number and capabilities. Application developers now routinely target the Web instead of operating systems. A core set of Web Standards – HTML, CSS, JavaScript and DOM -- form the foundation for most Web applications.

One guiding principle of the Web is that there is only one; the same Web standards and the same Web content should be usable on all Web devices. As such, Web applications are challenging for mobile devices. For example, they often demand certain screen sizes.

This paper discusses how web applications relate to other web content. The notion of "dynamicity" is introduced to measure how dynamic the content is. Finally, web applications for mobile devices are described".
Source:Håkon Wium Lie, CTO, Opera Software:
Mobile Web Applications

[DaveSawers]

Mobile devices are changing to support larger screen sizes such that special small screen designs should not be necessary much longer. The Apple iPhone is a good example and a new device unveiled in Italy yesterday with a flexible liquid crystal screen that can be unrolled to increase the viewing area gives us a clue to the way ahead.

BUT. Mobile devices are very expensive for web surfing because of the impact of all that traffic on cell phone networks. Using technologies like AJAX to reduce the amount of downloaded bytes will be important for quite a while yet.

If the internet continues to be clogged with spam, botnets and the like, the cost of internet usage may become linked with bandwidth again and efficient low bandwidth web design is again attractive.

[kgun]

Originally Posted by DaveSawers

BUT. Mobile devices are very expensive for web surfing because of the impact of all that traffic on cell phone networks. Using technologies like AJAX to reduce the amount of downloaded bytes will be important for quite a while yet.

This is february 2007. Costs will decrease and capacity increase. You have your mobile phone in your pocket from which you can

• Read and send eposts directly.
• Surf simple pages.
• Use web applications made for mobile devices.

There will always be small screens. It is about efficiency, entertainment, staying informed etc.

Example: You are on a holiday in a remote place (e. g. Canadian Wilderness) with only wireless connection to the internet. You get an important sound message on your mobile phone and you can respond at once.

This is for VIP persons in VIP companies (and young people of course).

There is a large market, not at least in Asia, where wireless communication increases most. So, also implement Babel fish translation on your site like I have done on OopSchool (se link in my sig), that is far from perfect, but good enough to understand the main message. It will be better in the future.

I can not see that this domain:

http://www.mobile4u.com/

is taken. What about

http://www.allr8.com/ Everything correct, browsing along the right edge etc :-)

Redirects to the following Italian site:
http://www.greenlinemobility.it/