This test consists in detecting captcha images and thus defining the applicability of the test.
Human check will be then needed to determine whether the alternative is pertinent.
Does each image (img tag) used as a CAPTCHA or test image, with an alt attribute, meet the following conditions? The content of the alt attribute describes the nature and purpose of the image
<img> tags of the page with an
"alt" attribute not within a link (css selector :
All the elements of Set1 identified as a CAPTCHA (see Notes for details about CAPTCHA characterisation).
For each element of Set2, raise a MessageA
MessageA : Check captcha alternative
- code : CheckCaptchaAlternative
- status: Pre-Qualified
- parameter :
"src"attribute, tag name, snippet
- present in source : yes
The page has no
<img> tag with an
"alt" attribute identified as a captcha (Set2 is empty)
In all other cases
An element is identified as a CAPTCHA when the “captcha” occurrence is found :
- on one attribute of the element
- or within the text of the element
- or on one attribute of one parent of the element
- or within the text of one parent of the element
- or on one attribute of a sibling of the element
- or within the text of a sibling of the element