Risks of AJAX

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Advanced Topic Presentation

By David Frank

What is AJAX

AJAX is a JavaScript object allowing to use XMLHttpRequest object easier and speeding up development of AJAX based projects.

It consists of a bound of methods which help to create queries, error handling, usage with HTML forms as well as connection timeouts and reconnecting.

The Best feature of AJAX is that it makes changes to the page without having to refresh it.

Risks of AJAX

TechnologyCulturalMarketing

Marketing Risk

Cultural Risk

Technology Risk

Technology Risk Reach Risk

All Browsers are different. Compatibility with ALL the available browsers is impossible. A feature considered to be very good in one browser will not even work in another. Every feature is thus designed to reach only the target browser. So, not all browsers can get the advantages of AJAX.

Technology Risk Maintenance Risk

Ajax code is difficult to maintain because it is complex. A lot of optimization techniques in the script are needed to improve performance. These lead to spaghetti code resulting in higher long term maintenance costs than the applications that are written in a traditional architecture that rely more on server side processing.

Technology Risk Forwards Compatibility Risk

Ajax applications have to continuously be rewritten as new browsers and operating systems are introduced in the technology industry. This is to accommodate changes in the layout engine, CSS interpreter, and the underlying mechanisms of JavaScript itself. Developers need to be one step ahead of all possible changes that would affect the user experience.

Cultural Risk Heterogenous culture and expectations

Ajax has a way of making things happen really quickly on a page and so without enough visual cues there will be bad usability. If an item on the web page is usually clicked rather than dragged (because of AJAX), then the user will not be comfortable with the interface, though the drag object might be easier to use. The problem of the Back button in web pages due to AJAX is one of the frequent usability issues encountered, since the Back button cannot undo the changes made by AJAX.

Cultural Risk Users are not very trainable

Not all users are fast learners. Most of the users will not feel comfortable with such an advanced technology. The users learn gradually and by the time they get acclimatized to the interface, the technology has changed, thus leading to a newer and higher technology interface.

Cultural Risk Short attention span

AJAX takes a lot of time to load. Making AJAX scripting to be supported in many browsers leads to huge file sizes for client side Ajax code. With almost half of the web users having dial-up internet connection, the risk here is that with short attention spans, users can become frustrated or bored by high latency or download times and abandon the session.

Ways to reduce RisksTechnology Risks

Usage of 3rd party frameworkThere are several well optimized third party AJAX frameworks that are available. These have already solved many of the cross browser issues. There are also constantly upgraded to support the latest updates of the browsers. By using these third party frameworks, a lot of time and money can be saved.

Ways to reduce RisksTechnology Risks

More processing on the serverThe size and complexity of a client side code can be reduced by moving as much processing as possible to the server. If the client has less code, it is easier to maintain and debug. A very good example of this is calling the server for raw HTML code instead of data, thereby eliminating the need to perform JavaScript transformations on the client.

Ways to reduce RisksTechnology Risks

Perform regular testingAJAX applications need to be tested continuously to ensure that long term success is achieved with the various browsers. The target browsers must also be reviewed from time to time so that the latest versions of the browsers, including the BETA versions, are taken into consideration while designing the pages.

Ways to reduce RisksCultural Risks

Affordance testing Affordance testing can be done in order to understand how user’s interact to web pages. Before using a functionality, another application with a similar functionality can be tried so that known pitfalls of AJAX can be avoided.

Ways to reduce RisksCultural Risks

Keep it lightweight

The amount of AJAX code should be reduced to as minimum as possible. The AJAX codes can be written by keeping the download speeds of a 56K modem. The page can be designed in such a way as to download within 15 seconds while using a dial-up connection.

Ways to reduce RisksCultural Risks

AJAX used only to increase functionalityAJAX should be used only where it’s necessary. For example, when trying to decide between a ‘clickable’ and a ‘draggable’ object, a draggable object can be used when there is a necessity to reorder items in a list. Otherwise, the ‘clickable’ object can be used. This will enhance user functionality and reduce any required user training.

Ways to reduce RisksCultural Risks

Liberal use of visual cuesVisual cues help in making interacting accessible to a more diverse audience. The user should be given enough visual cues to indicate that AJAX is working. These visual cues assist in the rapid training of users. One very good example of a visual cue is the red ‘loading’ box in Gmail. Gmail gives a red box with the words ‘loading’ inside it, when the browser has done loading the page and AJAX is now working on the page.

Conclusion Though there are several open standards like CSS

and HTML, the websites are being made to support advanced AJAXian techniques. Developers who want to improve their interfaces can use AJAX but will have to follow the examples of good interfaces such as Gmail. Gmail is an example of terrific innovation - but at the same time has designed the interface after understanding its users. Thus the best interface that uses AJAX comes only after taking considerably the various technological and cultural risks in today’s world.