SC1-1-1-text-alternative

This test belongs to 1.1.1 Non-text Content.

Status

Description

This test checks that non-text elements conveying information are providing sufficient textual alternatives or, if purely decorative, are hidden from assistive technologies.

Background

• WAI-ARIA 1.0 - Text Alternative Computation
• ARIA6: Using aria-label to provide labels for objects
• ARIA10: Using aria-labelledby to provide a text alternative for non-text content
• F38: Failure of Success Criterion 1.1.1 due to not marking up decorative images in HTML in a way that allows assistive technology to ignore them
• F30: Failure of Success Criterion 1.1.1 and 1.2.1 due to using text alternatives that are not alternatives (e.g., filenames or placeholder text)
• F39: Failure of Success Criterion 1.1.1 due to providing a text alternative that is not null (e.g., alt="spacer" or alt="image") for images that should be ignored by assistive technology
• F65: Failure of Success Criterion 1.1.1 due to omitting the alt attribute on img elements, area elements, and input elements of type "image"
• G196: Using a text alternative on one item within a group of images that describes all items in the group
• H2: Combining adjacent image and text links for the same resource
• H30: Providing link text that describes the purpose of a link for anchor elements
• H37: Using alt attributes on img elements
• H53: Using the body of the object element
• H67: Using null alt text and no title attribute on img elements for images that AT should ignore

Assumptions

• The techniques used for providing a textual alternative are accessibility supported. For more information read Accessibility Support.
• All elements are contained in the mark-up code in the examined web page snapshot. F20: Failure of Success Criterion 1.1.1 and 4.1.2 due to not updating text alternatives when changes to non-text content occur is not tested.
• Groups of images consist of img elements that are adjacent to each other and not wrapped in containers.
• The smallest readable font can be displayed on a matrix with a height of 5 and a width of 3. Smaller elements are considered decorative automatically.

Test properties

Property	Value
Test name	Provision of short text alternative
Success Criterion	1.1.1 Non-text Content
Test mode	SemiAuto
Test environment	Rendered page
Test subject	Web page state
User expertise and skills	No prior knowledge
User profile	Requires sight

Test procedure

Selector

//*[self::img or self::input[@type="image"] or self::area or self::embed or self::object]

Step 1: check element type (F65)

Check if the element is of type <img>,<area> or input[type=”image”]

if yes, continue with #Step 2: check mandatory attributes (F65)

else continue with #Step 8: compute text alternative

Step 2: check mandatory attributes (F65)

Check if one of the following attributes is present: aria-labelledby with valid destinations or alt , aria-label, title.

if yes, continue with #Step 3: check for img siblings (ARIA10 and G196)

else return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-failed1
Outcome	failed
ErrorMessage	The element must provide one of the following attributes: alt , aria-label, title or a aria-labelledby.
Pointer	position
Info

Step 3: check for img siblings (ARIA10 and G196)

Check if the selected element is an <img> element and has adjacent siblings of type <img>.

if yes, continue with #Step 4: ask for informational or functional group of images (ARIA10 and G196)

else continue with #Step 8: compute text alternative

Step 4: ask for informational or functional group of images (ARIA10 and G196)

if yes, continue with #Step 5: check for aria-labelledby implementation (ARIA10)

else continue with #Step 8: compute text alternative

Step 5: check for aria-labelledby implementation (ARIA10)

Check if the parent element of the current group has role="img" and an aria-labelledby attribute.

if yes, continue with #Step 6: ask if sufficiently described by textual alternative (ARIA10)

else continue with #Step 7: ask if sufficiently described by textual alternative (G196)

Step 6: ask if sufficiently described by textual alternative (ARIA10)

Concatenate the results of Text Alternative Computation Algorithm run on all elements referenced in the aria-labelledby attribute and assign it to variable T1.

All items of the group should be removed from the set of selector-matches after this step.

if yes, return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-passed1
Outcome	passed
Pointer	position
Info

else return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-failed2
Outcome	failed
ErrorMessage	Textual alternative T1 does not sufficiently describe the group of images.
Pointer	position
Info	Suggestions for textual alternative: {collection of repair-answers}

Step 7: ask if sufficiently described by textual alternative (G196)

Concatenate the results of Text Alternative Computation Algorithm run on all images and assign it to variable T1.

All items of the group should be removed from the set of selector-matches after this step.

if yes, return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-passed2
Outcome	passed
Pointer	position
Info

else return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-failed3
Outcome	failed
ErrorMessage	Textual alternative T1 does not sufficiently describe the group of images.
Pointer	position
Info	Suggestions for textual alternative: {collection of repair-answers}

Step 8: compute text alternative

Use the Text Alternative Computation Algorithm to compute the textual alternative provided and assign it to variable T1.

If T1 is empty and the current element is an <img>

continue with #Step 9: check if child of anchor (H2)

else if T1 is empty and the current element is NOT an <img>

continue with #Step 11: check dimensions (no text alternative)

else if T1 is NOT empty

continue with #Step 13: check text alternative validity (F30 and F39)

Step 9: check if child of anchor (H2)

Check if the img is child of an <a> element.

If yes, continue with #Step 10: check for anchor text (H2)

else continue with #Step 11: check dimensions (no text alternative)

Step 10: check for anchor text (H2)

Note: The img has no textual alternative at this test step.

Check if the parent anchor element or any of its children contains text.

if yes, return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-passed3
Outcome	passed
Pointer	position
Info

else return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-failed4
Outcome	failed
ErrorMessage	No text alternative for image contained in link without link text.
Pointer	position
Info

Step 11: check dimensions (no text alternative)

Check if the elements height is less or equal 5px or the elements width is less or equal 3px.

if yes, return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-passed4
Outcome	passed
Pointer	position
Info

else Continue with #Step 12: ask if decorative (no text alternative)

Step 12: ask if decorative (no text alternative)

if yes, return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-passed5
Outcome	passed
Pointer	position
Info

else return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-failed5
Outcome	failed
ErrorMessage	No sufficiently descriptive textual alternative for an element, which is not pure decoration.
Pointer	position
Info	Suggestions for textual alternative: {collection of repair-answers}

Step 13: check text alternative validity (F30 and F39)

Use the Validate Text Alternative algorithm to check if the textual alternative value is non-empty, as defined (contain 2 or more characters that are not white space characters or punctionmarks), not a filename, an URL or a placeholder text.

if valid, continue with #Step 14: check dimensions (valid text alternative) (F38)

else return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-failed6
Outcome	failed
ErrorMessage	Textual alternative is not valid.
Pointer	position
Info	The textual alternative is a filename, an URL, a placeholder text or does not contain 2 or more characters that are not white space characters or punctionmarks.

Step 14: check dimensions (valid text alternative) (F38)

Check if the elements height is less or equal 5px or the elements width is less or equal 3px.

if yes, continue with #Step 16: check for empty alt (F38)

else continue with #Step 15: ask if decorative (valid text alternative) (F38)

Step 15: ask if decorative (valid text alternative) (F38)

if yes, continue with #Step 16: check for empty alt (F38)

else continue with #Step 17: ask if sufficiently described by textual alternative

Step 16: check for empty alt (F38)

Note: The image has a textual alternative at this test step.

If the current element is an img, check, if an empty alt attribute or role="presentation" is provided.

if yes, return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-passed6
Outcome	passed
Pointer	position
Info

else return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-failed7
Outcome	failed
ErrorMessage	Image assessed as decorative cannot be ignored by assistive technologies
Pointer	position
Info	An empty alt attribute or role=”presentation” must be set.

Step 17: ask if sufficiently described by textual alternative

if yes, return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-passed7
Outcome	passed
Pointer	position
Info

else continue with #Step 18: ask if sufficiently described by adjacent text

Step 18: ask if sufficiently described by adjacent text

if yes, return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-passed8
Outcome	passed
Pointer	position
Info

else return

Property	Value
TestCase	SC1-1-1-text-alternative
Identifier	SC1-1-1-text-alternative-failed8
Outcome	failed
ErrorMessage	Textual alternative T1 is not sufficiently descriptive and the element is also not described in adjacent text.
Pointer	position
Info	Suggestions for texual alternative: {collection of repair-answers}

Activity diagram of transitions between steps 1 to 18

Activity diagram of test steps related to techniques and failures