accessibility-checker-engine
Version:
An automated accessibility checking engine for use by other tools
99 lines (84 loc) • 4.22 kB
HTML
<html lang="en-US">
<head>
<title>img_longdesc_misuse - Accessibility Checker Help</title>
<script>
RULE_MESSAGES = {"en-US":{"Pass_0":"Rule Passed","Potential_1":"Verify that the file designated by the 'longdesc' attribute contains valid HTML content (file extension not recognized)","group":" The 'longdesc' attribute must reference HTML content"}};
RULE_ID = "img_longdesc_misuse"
</script>
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-->
<!-- Title and messages generated at build time -->
<link rel="icon" href="https://ibm.com/able/favicon-32x32.png" type="image/png">
<link rel="icon" href="https://ibm.com/able/favicon.svg" type="image/svg+xml">
<link rel="stylesheet" href="../common/help.css" />
<script type="module">
import "https://1.www.s81c.com/common/carbon/web-components/version/v1.35.0/code-snippet.min.js";
import "https://1.www.s81c.com/common/carbon/web-components/version/v1.35.0/list.min.js";
</script>
<script src="https://cdn.jsdelivr.net/npm/marked/marked.min.js"></script>
<script src="../common/help.js"></script>
</head>
<body>
<div class="bx--grid toolHelp">
<div class="bx--row">
<div class="bx--col-sm-4 bx--col-md-8 bx--col-lg-16 toolHead">
<!-- Group message injected here -->
<h3 id="ruleMessage"></h3>
<!-- Severity level injected here -->
<div id="locLevel"></div>
<!-- Rule specific message injected here -->
<p id="groupLabel"></p>
</div>
</div>
<div class="bx--row">
<div class="bx--col-sm-4 bx--col-md-5 bx--col-lg-8 toolMain">
<!-- Start main panel -->
<mark-down><script type="text/plain">
### Why is this important?
Text alternatives provide important information that some people cannot be visually perceive.
When a short description is insufficient, the `longdesc` attribute can link to a URL containing a longer image description.
<!-- This is where the code snippet is injected -->
<div id="locSnippet"></div>
### What to do
* The `longdesc` attribute is inconsistently implemented across browsers. Where possible, it is preferable to provide a longer image description [using the `aria-describedby` attribute](https://www.w3.org/WAI/WCAG22/Techniques/aria/ARIA15)
* **Or**, verify the `longdesc` attribute value is a valid URL of an HTML page with a text description of the image
For example:
```
<img src="table.gif" alt="a complex table" longdesc="tabledescription.html" />
```
</script></mark-down>
<!-- End main panel -->
<!-- This is where the rule id is injected -->
<div id="ruleInfo"></div>
</div>
<div class="bx--col-sm-4 bx--col-md-3 bx--col-lg-4 toolSide">
<!-- Start side panel -->
<mark-down><script type="text/plain">
### About this requirement
* [IBM 1.1.1 Non-text content](https://www.ibm.com/able/requirements/requirements/#1_1_1)
* [H45: Using longdesc](https://www.w3.org/WAI/WCAG22/Techniques/html/H45)
### Who does this affect?
* People using a screen reader, including blind, low vision, and neurodivergent people
* People using text-only, monochrome, or Braille displays
* People using text-based browsers (e.g., Lynx) or audio interfaces
* People who turn off image-loading on their web browsers
</script></mark-down>
<!-- End side panel -->
</div>
</div>
</div>
</body>
</html>