What is HTML5 ARIA? I do not understand how to implement it.
What is ARIA?
ARIA emerged as a way to address the accessibility problem of using a markup language intended for documents, HTML, to build user interfaces (UI). HTML includes a great many features to deal with documents (P, h3,UL,TABLE) but only basic UI elements such as A, INPUT and BUTTON. Windows and other operating systems support APIs that allow (Assistive Technology) AT to access the functionality of UI controls. Internet Explorer and other browsers map the native HTML elements to the accessibility API, but the html controls are not as rich as the controls common on desktop operating systems, and are not enough for modern web applications Custom controls can extend html elements to provide the rich UI needed for modern web applications. Before ARIA, the browser had no way to expose this extra richness to the accessibility API or AT. The classic example of this issue is adding a click handler to an image. It creates what appears to be a clickable button to a mouse user, but is still just an image to a keyboard or AT user.
The solution was to create a set of attributes that allow developers to extend HTML with UI semantics. The ARIA term for a group of HTML elements that have custom functionality and use ARIA attributes to map these functions to accessibility APIs is a “Widget. ARIA also provides a means for authors to document the role of content itself, which in turn, allows AT to construct alternate navigation mechanisms for the content that are much easier to use than reading the full text or only iterating over a list of the links.
It is important to remember that in simple cases, it is much preferred to use native HTML controls and style them rather than using ARIA. That is don’t reinvent wheels, or checkboxes, if you don’t have to.
Fortunately, ARIA markup can be added to existing sites without changing the behavior for mainstream users. This greatly reduces the cost of modifying and testing the website or application.