Rule 1.3.6

Summary

This test consists in checking for each informative vector image (<svg> tag) are implemented correctly and checking each informative vector image have a "desc" tags or a "aria-label" attribute with relevante alternative.

Business description

Criterion

1.3

Test

1.3.6

Description

Chaque image vectorielle porteuse d'information (balise svg) et possédant une alternative vérifie-t-elle une de ces conditions (hors cas particuliers) ?

  • La balise svg possède un role="img"
  • La balise svg possède une propriété "aria-label" dont le contenu est pertinent et identique à l'attribut title s'il est présent
  • La balise svg possède une balise desc dont le contenu est pertinent et identique à l'attribut title de la balise svg s'il est présent
  • Un lien adjacent permet d'accéder à une alternative dont le contenu est pertinent et identique à l'attribut title de la balise svg s'il est présent

Level

A

Technical description

Scope

Page

Decision level

Semidecidable

Algorithm

Selection

Set1

All the <svg> tags of the page not within a link, not identified as captcha and with a not empty <desc> child tag (see Notes about captcha detection) (svg:not(a svg):has(desc:not(:matchesOwn(^\s*$)))

Set2

All the <svg> tags of the page not within a link, not identified as captcha and with a not empty "aria-label" attribute (see Notes about captcha detection) (svg[aria-label]:not([aria-label~=^\s*$]:not(a svg))

Set3

All the elements of Set1 identified as informative image by marker usage (see Notes for details about detection through marker)

Set4

All the elements of Set2 identified as informative image by marker usage (see Notes for details about detection through marker)

Set5

All the elements of Set1 identified neither as informative image, nor as decorative image by marker usage (see Notes for details about detection through marker)

Set6

All the elements of Set2 identified neither as informative image, nor as decorative image by marker usage (see Notes for details about detection through marker)

Set7

All the elements of Set3 with a "role" attribute with value "img"

Set8

All the elements of Set4 with a "role" attribute with value "img"

Set9

All the elements of Set5 with a "role" attribute with value "img"

Set10

All the elements of Set6 with a "role" attribute with value "img"

Process

Tests

Test1

For each element of Set3 and Set4, check the presence of the "role" attribute with value "img".

For each occurrence of false-result of Test1, raise a MessageA

Test2

For each element of Set4 and Set6, check the presence of the "role" attribute with value "img".

For each occurrence of false-result of Test2, raise a MessageA

Test3

For each element of Set6 and Set7, check whether the "aria-label" attribute is not empty when present.

For each occurrence of false-result of Test3, raise a MessageB.

Test4

For each element of Set8 and Set9, check whether the "aria-label" attribute is not empty when present.

For each occurrence of false-result of Test4, raise a MessageC.

Test5

For each element of Set6 and Set7, check whether the "aria-label" attribute is identical to the "title" attribute when they are both present.

For each occurrence of false-result of Test5, raise a MessageB.

Test6

For each element of Set8 and Set9, check whether the "aria-label" attribute is identical to the "title" attribute when they are both present.

For each occurrence of false-result of Test6, raise a MessageC.

Test7

For each element of Set6 and Set7, check whether the content of the <desc> child tag is not empty when present.

For each occurrence of false-result of Test7, raise a MessageB.

Test8

For each element of Set8 and Set9, check whether the content of the <desc> child tag is not empty when present.

For each occurrence of false-result of Test8, raise a MessageC.

Test9

For each element of Set6 and Set7, check whether the content of the <desc> child tag is identical to the "title" attribute when they are both present.

For each occurrence of false-result of Test9, raise a MessageB.

Test10

For each element of Set8 and Set9, check whether the content of the <desc> child tag is identical to the "title" attribute when they are both present.

For each occurrence of false-result of Test10, raise a MessageC.

Messages

For each occurrence of Set6 and Set7 that return a true on Test3, Test5, Test7 AND Test9, raise a MessageD

For each occurrence of Set8 and Set9 that return a true on Test4, Test6, Test8 AND Test10, raise a MessageE

MessageA : svg without role img attribute
  • code : SvgWithoutRoleImage
  • status: Failed
  • parameter : tag name, Snippet
  • present in source : yes
MessageB : Informative svg with not bad alternative definition
  • code : InformativeSvgWithNotPertinentAlternative
  • status: Pre-Qualified
  • parameter : "role" attribute, "aria-label" attribute, "title" attribute, tag name, Snippet
  • present in source : yes
MessageC : Check nature of svg with bad alternative
  • code : CheckNatureOfSvgWithNotPertinentAlternative
  • status: Pre-Qualified
  • parameter : "role" attribute, "aria-label" attribute, "title" attribute, tag name, Snippet
  • present in source : yes
MessageD : Check alternative pertinence of informative svg
  • code : CheckPertinenceOfAlternativeOfInformativeSvg
  • status: Pre-Qualified
  • parameter : "role" attribute, "aria-label" attribute, "title" attribute, tag name, Snippet
  • present in source : yes
MessageE : Check nature of svg and alternative pertinence
  • code : CheckNatureOfSvgAndAlternativePertinence
  • status: Pre-Qualified
  • parameter : "role" attribute, "aria-label" attribute, "title" attribute, tag name, Snippet
  • present in source : yes

Analysis

Failed

The page contains at least one <svg> without a "role" attribute equals to "img" (Test1 OR Test2 returns false for at least one element)

Not Applicable

The page has no <svg> tag (Set1 and Set2 are empty)

Pre-qualified

In all other cases

Notes

The <svg> not identified by marker, without "role" attribute equals to "img" are invalidated in this test. The test 1.2.4 asks to check that is attribute is present for decorative <svg>. We can deduce this attribute has to be present for all <svg> in any way. To avoid to invalidate a same element twice, we decided to ONLY invalid this pattern in this test.

Markers

Informative images markers are set through the INFORMATIVE_IMAGE_MARKER parameter.

Decorative images markers are set through the DECORATIVE_IMAGE_MARKER parameter.

The value(s) passed as marker(s) will be checked against the following attributes:

  • class
  • id
  • role

Captcha detection

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