@instructure/canvas-rce
Version:
A component wrapping Canvas's usage of Tinymce
60 lines (59 loc) • 2.11 kB
JavaScript
/*
* Copyright (C) 2018 - present Instructure, Inc.
*
* This file is part of Canvas.
*
* Canvas is free software: you can redistribute it and/or modify it under
* the terms of the GNU Affero General Public License as published by the Free
* Software Foundation, version 3 of the License.
*
* Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
* details.
*
* You should have received a copy of the GNU Affero General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import formatMessage from '../../../../format-message';
export default {
id: 'img-alt',
test: elem => {
if (elem.tagName !== 'IMG') {
return true;
}
const alt = elem.hasAttribute('alt') ? elem.getAttribute('alt') : null;
return alt !== null;
},
data: elem => {
const alt = elem.hasAttribute('alt') ? elem.getAttribute('alt') : null;
const decorative = alt !== null && alt.replace(/\s/g, '') === '';
return {
alt: alt || '',
decorative
};
},
form: () => [{
label: formatMessage('Add alt text for the image'),
dataKey: 'alt',
disabledIf: data => data.decorative
}, {
label: formatMessage('Decorative image'),
dataKey: 'decorative',
checkbox: true
}],
update: (elem, data) => {
if (data.decorative) {
elem.setAttribute('alt', '');
elem.setAttribute('role', 'presentation');
} else {
elem.setAttribute('alt', data.alt);
elem.removeAttribute('role');
}
return elem;
},
message: () => formatMessage('Images should include an alt attribute describing the image content.'),
why: () => formatMessage('Screen readers cannot determine what is displayed in an image without alternative text, which describes the content and meaning of the image.'),
link: 'https://www.w3.org/TR/WCAG20-TECHS/H37.html',
linkText: () => formatMessage('Learn more about using alt text for images')
};