3.2 Provide text links to emulate client-side image maps
Contents
WAI Checkpoint 1.5
Full WAI text: "If you use images and image maps: until user agents render text equivalents for client-side image map links, provide redundant text links for each active region of a client-side image map." Image maps are images which are made up of many parts, each of which is a separate graphical button or link. The parts with the link are the "active regions".
With client-side image maps, the user clicks on a point on the image map and the coordinates of the point they click on are collected and processed by their browser. The browser then sends a request to the server where the site is hosted, to activate a command.
A user agent is a piece of software for accessing Web content. User agents could be desktop graphical browsers, text browsers, voice browsers, mobile phones, multimedia players, plug-ins, and some software assistive technologies used in conjunction with browsers such as screen readers, screen magnifiers, and voice recognition software.
Redundant text links correspond to the links contained in the active regions of the image map but are presented in text format, in addition to the links in the image map itself.
Not all user agents are capable of automatically providing users with a list of redundant text links. Until such time as they do so, you must provide a redundant set of links.
Rationale
Because image maps tend to rely on the "point and click" style of interaction, they can be inherently unusable for anyone not using a mouse. The user may not work with a mouse if they are working with a laptop, a mobile device, a screen reader or if they have limited manual dexterity and can't control the mouse accurately. Providing redundant text links allows these users to access the controls or pages behind the image map.
Directions and Techniques
Use the "A" element to provide redundant text links
See WAI recommended techniques on providing redundant text links with the "A" element
How you could check for this:
Test the site with a text only browser
A text only browser cannot recognise images and will present the text only. Pages with server-side image maps will be unusable unless redundant text links are provided.
Guidelines for Web Accessibility - Priority 3- 3.1 Ensure that text and background have sufficient contrast for people with colour deficient vision
- 3.2 Provide text links to emulate client-side image maps
- 3.3 Expand the first occurrence of any abbreviation or acronym
- 3.4 Identify the primary language of the document text
- 3.5 Place distinguishing information at the beginning of headings, paragraphs, lists, etc.
- 3.6 Supplement text with graphic or auditory presentations where they will facilitate comprehension
- 3.7 Provide summaries for tables
- 3.8 Provide abbreviations for table header labels
- 3.9 Identify groups of related links and provide a way to bypass them
- 3.10 Provide a linear alternative for parallel, word-wrapped columns of text
- 3.11 Create a logical tab order through links, form controls, and objects
- 3.12 Provide keyboard shortcuts to important links, form controls, and groups of form controls
- 3.13 Separate adjacent links with non-link, printable characters surrounded by spaces
- 3.14 Provide navigation bars
- 3.15 If search functions are provided, enable different types of searches for different skill levels and preferences
- 3.16 Provide information about documents comprising multiple pages
- 3.17 Provide a means to skip over multi-line ASCII art
- 3.18 Create a style of presentation that is consistent across pages
- 3.19 Include default text in form text boxes
- 3.20 Provide information to enable users to receive documents according to their preferences
