Summary
This test consists in checking whether each button associated with an image that handles information has a relevant alternative.
Business description
Criterion
Test
Description
For each button associated with an image (input tag with the attribute type=“image”), and with an alt attribute, is the content of this attribute relevant (except in particular cases)?
Level
A
Technical description
Scope
Page
Decision level
Semi-Decidable
Algorithm
Selection
Set1
All the <input> tags with a "type" attribute equals to “image” and an "alt" attribute (css selector : input[type=image][alt])
Process
Test1
For all elements of Set1, check whether the content of the "alt" attribute is not relevant (see Notes for details about relevancy test).
For each occurrence of true-result of Test1, raise a MessageA.
For each occurrence of false-result of Test1, raise a MessageB
MessageA
- code : NotPertinentAlt
- status: Failed
- parameter :
"alt"attribute,"src"attribute, tag name - present in source : yes
MessageB
- code : CheckPertinenceOfAltAttributeOfInformativeImage
- status: Pre-Qualified
- parameter :
"alt"attribute,"src"attribute, tag name - present in source : yes
Analysis
Failed
At least one <input> tag with a "type" attribute equals to “image” has an irrelevant "alt" attribute (Test1 returns true for at least one element)
Pre-qualified
The alternatives of all the <input> tags with a "type" attribute equals to “image” need to be manually checked (Test1 returns false for all the elements of Set1)
Not Applicable
The page has no <input> tag with a "type" attribute equals to “image” tag and an "alt" attribute (Set1 is empty)
Notes
The content of the "alt" attribute is seen as not relevant if :
- empty
- only composed of non-alphanumerical characters
- identical to the
"src"attribute - it has an extension of image type (loaded by the nomenclature named ImageFileExtensions composed of : jpg, gif, jpeg, png, bmp)