Techniques for WCAG 2.0

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FLASH30: Specifying accessible names for image buttons


This technique relates to:

User Agent and Assistive Technology Support Notes

See User Agent Support for Flash for general information on user agent support.


For image based Button components the accessible name needs to be set to provide a functional label. This label indicates the button's function, but does not attempt to describe the image. The label is especially important if there are multiple buttons on the page that each lead to different results.

The accessible name for a button may need to be updated if the button changes during the use of the Flash movie.


Example 1: Accessible name for a simple image button

In this example, an icon based button is given an accessible name through scripting. When the button is clicked a web page is opened.

Example Code:

//provide text equivalent for image button
this.check_btn.accessibilityProperties = new AccessibilityProperties(); = "Check page validation";

//set up event listener and function to navigate to URL

this.check_btn.addEventListener(MouseEvent.CLICK, onClickHandler);

function onClickHandler(e: MouseEvent): void {
  var btn =;
  var url: String = "";
  var request: URLRequest = new URLRequest(url);
  navigateToURL(request, '_blank');

The result is demonstrated in the working version of Accessible name for a simple image button. The source of Accessible name for a simple image button is available.

Example 2: Accessible name for a dynamic image button

Example Code:

import fl.controls.Button;
import fl.accessibility.ButtonAccImpl;


var soundIsMuted = false;
var myButton: Button = new Button();
myButton.label = "";
myButton.x = myButton.y = 10;
myButton.width = myButton.height = 50;
updateAccName(myButton, "mute sound");
myButton.setStyle("icon", unmuted);
myButton.addEventListener(MouseEvent.CLICK, handleBtnClick);

function handleBtnClick(e) {
  soundIsMuted = ! soundIsMuted;
  myButton.setStyle("icon", soundIsMuted? muted: unmuted);
  updateAccName(myButton, soundIsMuted? "unmute sound": "mute sound");

function updateAccName(obj, newName: String) {
  if (! obj.accessibilityProperties)
  obj.accessibilityProperties = new AccessibilityProperties(); = newName;
  if (Capabilities.hasAccessibility)



When a Flash Movie contains image based buttons, confirm that:

  1. An accessible name is provided for the button that describes the button's action

  2. If the button's action changes (for example when it is clicked) the accessible name changes correspondingly

Expected Results

If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.