Accessible Google Charts
Date : 2008 01 09 Category : Tech & Development
AjaxianAccessibility is something most developers consider an afterthought but not Chris Heilmann, web architect at Yahoo!. As a member of the Yahoo! Accessibility Stakeholders group he takes issues concerning accessibility very seriously and makes it a top consideration in everything he builds.
Chris Heilmann recently described his technique for making Google Charts more accessible for those who cannot see pie charts. His technique allows for standard accessible data tables to be converted to charts thus ensuring that visitors using screen readers can take advantage of the data while allowing users of traditional browsers to view the actual charts:
Using this script you can take a simple, valid and accessible data table…and it gets automatically converted to a pie chart.
Simply add the script to the end of the body and it’ll convert all tables with a class called “tochart”. You can define the size (widthxheight) and the colour as a hexadecimal triplet as shown in this example. If you leave size and colour out, the script will use presets you can alter as variables in the script itself.
To verify his code, Chris enlisted the help of a blind friend, also a member of the Yahoo! Accessibility Stakeholders group, who tested it with JAWS.
The script has also been enhanced to allow the creation of accessible data tables when pulling charts via the APIs verbose mode.
As always, it’s best to see it in action in order to truly appreciate it. I commend Chris and the Yahoo! Accessibility Stakeholders group for their efforts in making the web more accessible to all.