Creating alternatives
As there is not a consistent method of incorporating AJAX it must be weighed up to how useful it is in the performance of a website? As AJAX creates a buffer between the user interface and the website a users actions can be uploaded while the previous content was sent.
The result of well implemented AJAX can leave users with smooth transitions while interacting with a web page. As AJAX can be used to enhance the usability of a site it can be seen as a useful tool to aid accessibility. Below are some factors relating to AJAX and Accessibility in some of the common uses-:
Use of AJAX |
User Interface |
Scripting Accessibility Affects |
|
AJAX |
No AJAX |
|
|
Submitting a form |
User is updated to the form process. |
Any details checked on the server could take an extra step in the process. |
If the page is not refreshed some users will not be aware of the form being submitted and this restricts the use of the form. |
Creating suggestions for a text field |
User can be given a suggestion from a large dataset. This decreases the amount of effort required to fill in the field. |
It is impossible for this functionality to be introduced unless all the possible values are loaded when the page initially loads. This is only possible for small data sets. |
The use of suggestions can increase accessibility by reducing the amount of keystrokes to fill in a form. This aids users with reduced mobility. |
Using a tabbed plane to dynamically display the content |
User loads up only the information required. This reduces loading time. |
All data for all tabbed planes would be loaded at the start creating long loading time. Alternatively the information could be spread over several pages. Any updates to the page would require the whole page to reload. |
This can minimise scrolling on a page but needs to be implemented in a way that assistive software can understand. All dynamic content must be given an alternative method to be retrieved. |
Dynamically filling drop down fields |
Depending on previous criteria the next drop down list can be populated with relevant data. For example car type followed by car model. By using AJAX, data can be calculated from large data sets. |
Either load the information in the JavaScript or add several stages to input the data with responses from the server. |
User only has to select from relevant data. This helps users with low motor ability. The dynamic loading of fields could confuse some assistive technologies if they use a buffer to convey the information to the user. |
Displaying content on mouse over events |
Useful to add extra information to the page. |
Without AJAX this information would have to be loaded initially with the page within the structure. |
Generally unfriendly as the event is triggered by the mouse. Screen reader would also have a problem as it would be likely that the content would not be in a logical order within the page structure. |
The tutorial looks at how to implement some of these techniques and how to build them in a way that disabled users could also interact with. Overall there is little a designer can do to fully implement an accessible system without sticking to basic and static html pages. However the implementation of a link that turns off the inaccessible methods gives the user the best change of accessing the content.