Business rules manual
RGAA v4.0.0
Theme 8: Mandatory elements
Rule 8.4.1

Rule 8.4.1

Summary

We check whether the language specified for each textual element of the page is correct (regarding the code list given in the following page http://www.loc.gov/standards/iso639-2/php/code_list.php) and relevant.

Business description

Criterion

8.4

Test

8.4.1

Description

Pour chaque page web ayant une langue par défaut, le code de langue vérifie-t-il ces conditions ?

  • Le code de langue est valide.
  • Le code de langue est pertinent.

Level

A

Technical description

Scope

Page

Decision level

Semi-Decidable

Algorithm

Selection

Set1

The <html> tag with a lang or xml:lang attribute.

Set2

The textual tags (tags with a title attribute, an alt attribute or some content) without lang or xml:lang attribute. These attributes can be set to the current tag or to one of its ascendants.

Set3

All the textual elements of the page which are not overidden by a lang attribute.

Set4

All the textual elements of the page which are overidden by a lang attribute.

Process

Test 1

We extract the language code from the lang or the xml:lang attributes from elements of Set2. If these attributes are both set and different, we keep the xml:lang attribute if the doctype of the page is found within the “XhtmlDoctypeDeclarations” whitelist, and we keep the lang attribute instead.

For each extracted lang attribute, we check its validity regarding the “ValidLanguageCode” whitelist

MessageA : Wrong Language Declaration (test 1)
  • code: WrongLanguageDeclaration
  • status: Failed
  • parameter: none
  • present in source: yes

Test 2

We extract the language code from the lang or the xml:lang attributes from elements of Set2. If these attributes are both set and different, we keep the xml:lang attribute if the doctype of the page is found within the “XhtmlDoctypeDeclarations” whitelist, and we keep the lang attribute instead

For each extracted lang attribute, we check its validity regarding the “ValidLanguageCode” whitelist

MessageA : Wrong Language Declaration (test 2)
  • code: WrongLanguageDeclaration
  • status: Failed
  • parameter: none
  • present in source: yes

Test3

We detect the language of the textual elements of the page which are not overidden by a lang attribute (Set3).

IF the detected language corresponds to the specified language AND the detection is seen as unreliable

THEN raise Message A and return Pre-Qualified

ELSE IF the detected language doesn’t corresponds to the specified language AND the detection is seen as reliable

THEN raise Message B and return FAILED

ELSE IF the detected language doesn’t corresponds to the specified language AND the detection is seen as unreliable

THEN raise Message Cand return Pre-Qualified

ELSE return PASSED

Test4

We detect the language of the textual elements of the page which are overidden by a lang attribute (Set4).

IF the detected language corresponds to the specified language AND the detection is seen as unreliable

THEN raise MessageA and return Pre-Qualified

ELSE IF the detected language doesn’t corresponds to the specified language AND the detection is seen as reliable

THEN raise MessageB and return FAILED

ELSE IF the detected language doesn’t corresponds to the specified language AND the detection is seen as unreliable

THEN raise MessageC and return Pre-Qualified

ELSE return PASSED

MessageA : Suspected Relevant Language Declaration
  • code: SuspectedRelevantLanguageDeclaration
  • status: Pre-Qualified
  • parameter: the extracted language, the detected language, and an extraction of the text (limited to 200 charachters) from which the detection has been applied
  • present in source: yes
MessageB : Unrelevant Language Declaration
  • code: UnrelevantLanguageDeclaration
  • status: Failed
  • parameter: the extracted language, the detected language, and an extraction of the text (limited to 200 charachters) from which the detection has been applied
  • present in source: yes
MessageC : Suspected Unrelevant Language Declaration
  • code: SuspectedUnrelevantLanguageDeclaration
  • status: Pre-Qualified
  • parameter: the extracted language, the detected language, and an extraction of the text (limited to 200 charachters) from which the detection has been applied
  • present in source: yes

Analysis

Not Applicable

The page has no language declarations (Set1 and Set2 are empty)

Failed

Test1 OR Test2 OR Test3 OR test4 returns FAILED

Passed

Test1 AND Test2 return true AND Test3 AND Test4 return PASSED

Pre-qualified

Test3 OR test4 returns Pre-Qualified

Files

Rule 8.3.1Rule 8.5.1