The aria-roledescription attribute changes the way screen readers announce the role of an element. Intended to give authors a way to provide a localised and human-readable description for a role, it has the capacity to both enhance and seriously break accessibility for screen reader users.
The accessible SVG line graphs post explains how to use ARIA table semantics to make that form of data visualisation accessible to screen readers. This article uses the same ARIA based approach to make a screen reader accessible SVG flowchart.
The Accessibility Object Model (AOM) is an experimental JavaScript API that enables developers to modify the browser accessibility tree. The AOM has four phases, and support for phase one recently landed in Chrome Canary behind the flag.
SVG is often used for data visualisation, but because SVG lacks the semantics to express structures like bar charts, line graphs, and scatter plots, the content is difficult for screen reader users to interpret. The solution is to use the technique for creating accessible SVG tables as your starting point.
SVG has no native semantics for representing structures like tables, but ARIA1.1 introduces a number of roles that can be used to polyfill the necessary semantic information.
ARIA (Accessible Rich Internet Applications) is a suite of specifications from the W3C. Knowing which specification has the information you need isn’t always obvious, so this post briefly introduces each specification and where it fits into the overall ARIA landscape.