accessibility-developer-tools
Version:
This is a library of accessibility-related testing and utility code.
42 lines (39 loc) • 1.7 kB
JavaScript
// Copyright 2012 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
goog.require('axs.AuditRules');
goog.require('axs.browserUtils');
goog.require('axs.constants.Severity');
goog.require('axs.properties');
goog.require('axs.utils');
axs.AuditRules.addRule({
name: 'imagesWithoutAltText',
heading: 'Images should have a text alternative or presentational role',
url: 'https://github.com/GoogleChrome/accessibility-developer-tools/wiki/Audit-Rules#ax_text_02',
severity: axs.constants.Severity.WARNING,
relevantElementMatcher: function(element, flags) {
return axs.browserUtils.matchSelector(element, 'img') && !flags.hidden;
},
test: function(image) {
var imageIsPresentational = (image.hasAttribute('alt') && image.alt == '') || image.getAttribute('role') == 'presentation';
if (imageIsPresentational)
return false;
var textAlternatives = {};
axs.properties.findTextAlternatives(image, textAlternatives);
var numTextAlternatives = Object.keys(textAlternatives).length;
if (numTextAlternatives == 0)
return true;
return false;
},
code: 'AX_TEXT_02'
});