autocomplete attribute has valid value

  • Rule Type:atomic
  • Rule Id: 73f2c2
  • Last modified: Jul 07, 2020
  • Accessibility Requirements Mapping:
    • 1.3.5 Identify Input Purpose (Level: AA)
      • Learn More about 1.3.5 (Identify Input Purpose)
      • Required for conformance to WCAG 2.1 and above on level AA and above.
      • Outcome mapping:
        • Any failed outcomes: success criterion is not satisfied.
        • All passed outcomes: success criterion needs further testing.
        • An inapplicable outcome: success criterion needs further testing.

Description

This rule checks that the HTML autocomplete attribute has a correct value.

Applicability

The rule applies to any HTML input, select and textarea element with an autocomplete attribute that is a set of one or more space separated tokens, except if one of the following is true:

Expectation 1

The autocomplete attribute is a single term, or a space separated list of terms.

Expectation 2

The autocomplete term(s) follow the HTML specification - Autofill detail tokens, which requires that it/they match the following in the correct order:

  1. Has a value that starts with "section-" (optional)
  2. Has either "shipping" or "billing" (optional)
  3. Has either "home", "work", "mobile", "fax" or "pager" (optional, only for "email", "impp", "tel" or "tel-*")
  4. Has a correct autocomplete field (required)

Note: Autocomplete terms are case insensitive. When multiple terms are used, they must be used in the correct order.

Expectation 3

The correct autocomplete field is an appropriate field for the form control.

Assumptions

For this rule, it is assumed that the autocomplete attribute is not used on form fields that do not correspond to an autocomplete field described in the HTML 5.2 specification. If the autocomplete field is used to describe "custom" taxonomy, rather than that described in the specification, this rule may produce incorrect results.

Accessibility Support

  • While autocomplete in a promising technique for supporting personalization in HTML, support for this is fairly limited.
  • Implementation of Presentational Roles Conflict Resolution varies from one browser or assistive technology to another. Depending on this, some elements can have a semantic role of none and fail this rule with some technology but users of other technologies would not experience any accessibility issue.
  • Some user agents treat the value of the aria-disabled attribute as case-sensitive.

Background

The intent of this rule is to ensure that the autocomplete attribute can be used to support personalization. Many users may find it easier to fill out forms if those can be styled or laid out in a way that is familiar to them. Assistive technologies can do this when a form control is marked up in such a way that its purpose can be understood. For instance, assistive technologies could add familiar icons and colors to different fields, making it easier for the user to understand what the form does.

Test Cases

Passed

Passed Example 1

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Single autocomplete term.

<label>Username<input autocomplete="username"/></label>

Passed Example 2

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Single autocomplete term for select.

<select autocomplete="bday-month">
	<option>January</option>
	<option>...</option>
</select>

Passed Example 3

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Autocomplete term, only valid for textarea.

<textarea autocomplete="Street-Address"></textarea>

Passed Example 4

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Two autocomplete terms.

<label>Work email<input autocomplete="Work Email"/></label>

Passed Example 5

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Autocomplete using section-*

<label>Email<input autocomplete="section-partner email"/></label>

Passed Example 6

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Triple autocomplete terms.

<label>Address<input type="text" autocomplete="section-primary billing address-line1"/></label>

Passed Example 7

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Full length autocomplete terms.

<label>Email<input autocomplete="section-primary shipping work email"/></label>

Passed Example 8

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This input element has an explicit role of none. However, it is focusable (by default). Thus it has a semantic role of textbox due to Presentational Roles Conflict Resolution. It has a single autocomplete term.

<label>Username<input role="none" autocomplete="username"/></label>

Passed Example 9

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The input element does not participates in sequential focus navigation, but still has a semantic role that is a widget role, and has a single autocomplete term.

<label>Username<input tabindex="-1" autocomplete="username"/></label>

Passed Example 10

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The input element does not have a semantic role that is a widget role, but still participates in sequential focus navigation because of the tabindex attribute, and has a single autocomplete term.

<label>Username<input role="banner" tabindex="0" autocomplete="username"/></label>

Failed

Failed Example 1

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Unknown autocomplete term.

<label>Username<input autocomplete="badterm"/></label>

Failed Example 2

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Term work not allowed before photo.

<label>Photo<input autocomplete="work photo"/></label>

Failed Example 3

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Invalid order of terms.

<label>Email<input autocomplete="work shipping email"/></label>

Failed Example 4

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Comma separated rather than space separated list.

<label>Email<input autocomplete="work,email"/></label>

Failed Example 5

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Autocomplete is inappropriate for the type of field.

<label>Email<input type="number" autocomplete="email"/></label>

Inapplicable

Inapplicable Example 1

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Inapplicable element.

<button autocomplete="username"></button>

Inapplicable Example 2

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Autocomplete attribute is empty ("").

<label>Username<input autocomplete=""/></label>

Inapplicable Example 3

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The element is hidden through display:none.

<label>Username<input autocomplete="username" style="display:none"/></label>

Inapplicable Example 4

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The input element has a type attribute that is in the button state.

<label>Username<input type="button" autocomplete="username"/></label>

Inapplicable Example 5

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The input element has a type attribute that is in the hidden state.

<label>Username<input type="hidden" autocomplete="username"/></label>

Inapplicable Example 6

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The input element has an HTML disabled attribute.

<label>Username<input autocomplete="username" disabled/></label>

Inapplicable Example 7

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The input element has an aria-disabled attribute with value true.

<label>Username<input autocomplete="username" aria-disabled="true"/></label>

Inapplicable Example 8

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Non-widget element that does not participate in sequential focus navigation.

<label>Username<input type="button" role="none" disabled autocomplete="username"/></label>

Inapplicable Example 9

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Autocomplete attribute contains no tokens.

<label>Username<input autocomplete=" "/></label>

Glossary

Attribute value

The attribute value of an attribute set on an HTML element is the value that the attribute gets after being parsed and computed according to specifications. It may differ from the value that is actually written in the HTML code due to trimming whitespace or non-digits characters, default values, or case-insensitivity.

Some notable case of attribute value, among others:

  • For enumerated attributes, the attribute value is either the state of the attribute, or the keyword that maps to it; even for the default states. Thus <input type="image" /> has an attribute value of either Image Button (the state) or image (the keyword mapping to it), both formulations having the same meaning; similarly, "an input element with a type attribute value of Text" can be either <input type="text" />, <input /> (missing value default), or <input type="invalid" /> (invalid value default).
  • For boolean attributes, the attribute value is true when the attribute is present and false otherwise. Thus <button disabled>, <button disabled="disabled"> and <button disabled=""> all have a disabled attribute value of true.
  • For attributes whose value is used in a case-insensitive context, the attribute value is the lowercase version of the value written in the HTML code.
  • For attributes that accept numbers, the attribute value is the result of parsing the value written in the HTML code according to the rules for parsing this kind of number.
  • For attributes that accept sets of tokens, whether space separated or comma separated, the attribute value is the set of tokens obtained after parsing the set and, depending on the case, converting its items to lowercase (if the set is used in a case-insensitive context).
  • For aria-* attributes, the attribute value is computed as indicated in the WAI-ARIA specification.

This list is not exhaustive, and only serves as an illustration for some of the most common cases.

Explicit Semantic Role

The explicit semantic role of an element is determined by its role attribute (if any).

The role attribute takes a list of tokens. The explicit semantic role is the first valid role in this list. The valid roles are all non-abstract roles from WAI-ARIA Specifications. If the element has no role attribute, or if it has one with no valid role, then this element has no explicit semantic role.

Other roles may be added as they become available. Not all roles will be supported in all assistive technologies. Testers are encouraged to adjust which roles are allowed according to the accessibility support base line. For the purposes of executing test cases in all rules, it should be assumed that all roles are supported by assistive technologies so that none of the roles fail due to lack of accessibility support.

Accessibility Support for Explicit Semantic Role

Some browsers and assistive technologies treat the tokens of the role attribute as case-sensitive. Unless lowercase letters are used for the value of the role attribute, not all user agents will be able to interpret the tokens correctly. ARIA in HTML (working draft) also specifies that authors must use lowercase letters for the role and aria-* attributes.

Included in the accessibility tree

Elements included in the accessibility tree of platform specific accessibility APIs. Elements in the accessibility tree are exposed to assistive technologies, allowing users to interact with the elements in a way that meet the requirements of the individual user.

The general rules for when elements are included in the accessibility tree are defined in the core accessibility API mappings. For native markup languages, such as HTML and SVG, additional rules for when elements are included in the accessibility tree can be found in the HTML accessibility API mappings (working draft) and the SVG accessibility API mappings (working draft).

Note: Users of assistive technologies might still be able to interact with elements that are not included in the accessibility tree. An example of this is a focusable element with an aria-hidden attribute with a value of true. Such an element could still be interacted with using sequential keyboard navigation regardless of the assistive technologies used, even though the element would not be included in the accessibility tree.

Examples for Included in the accessibility tree

Note: The examples presented here are non-normative and not testable. They serve to illustrate some common pitfalls about the definition and to help implementers of ACT rules understand it.

This span element is included in the accessibility tree (by default, elements are included in the accessibility tree).

<span>ACT rules</span>

This span element is not included in the accessibility tree because it is hidden to everybody by the CSS property.

<span style="display:none">ACT rules</span>

This span element is not included in the accessibility tree because it is explicitly removed by the aria-hidden attribute.

<span aria-hidden="true">ACT rules</span>

This span element is positioned off screen, hence is not visible, but is nonetheless included in the accessibility tree.

<span style="position: absolute; top:-9999em">ACT rules</span>

Although the span element with an id of "label" is not itself included in the accessibility tree, it still provides an accessible name to the other span, via the aria-labelledby attribute. Thus, it is still indirectly exposed to users of assistive technologies. Removing an element from the accessibility tree is not enough to remove all accessibility concerns from it since it can still be indirectly exposed.

<span id="label" style="display:none">ACT rules</span>
<span aria-labelledby="label">Accessibility Conformance Testing rules</span>

Although this input element is not included in the accessibility tree, it is still focusable, hence users of assistive technologies can still interact with it by sequential keyboard navigation. This may result in confusing situations for such users (and is in direct violation of the fourth rule of ARIA (working draft)).

<input type="text" aria-hidden="true" name="fname" />

Outcome

An outcome is a conclusion that comes from evaluating an ACT Rule on a test subject or one of its constituent test target. An outcome can be one of the three following types:

  • Inapplicable: No part of the test subject matches the applicability
  • Passed: A test target meets all expectations
  • Failed: A test target does not meet all expectations

Note: A rule has one passed or failed outcome for every test target. When there are no test targets the rule has one inapplicable outcome. This means that each test subject will have one or more outcomes.

Note: Implementations using the EARL10-Schema can express the outcome with the outcome property. In addition to passed, failed and inapplicable, EARL 1.0 also defined an incomplete outcome. While this cannot be the outcome of an ACT Rule when applied in its entirety, it often happens that rules are only partially evaluated. For example, when applicability was automated, but the expectations have to be evaluated manually. Such "interim" results can be expressed with the incomplete outcome.

Semantic Role

The semantic role of an element is determined by the first of these cases that applies:

  1. Conflict If the element is marked as decorative, but the element is included in the accessibility tree; or would be included in the accessibility tree when its hidden state is false, then its semantic role is its implicit role.
  2. Explicit If the element has an explicit role, then its semantic role is its explicit role.
  3. Implicit The semantic role of the element is its implicit role.

Accessibility Support for Definition of Semantic Role for Semantic Role

  • There exist popular web browsers and assistive technologies which do not correctly implement Presentational Roles Conflict Resolution. These technologies will not include in the accessibility tree elements that should be, according to Specifications. Thus, some elements that should have their semantic role fixed by case Conflict above are instead falling into case Explicit and are hidden for users of assistive technologies.
  • A similar conflict exists for focusable elements with a aria-hidden="true" attribute. The WAI ARIA specification does not explain how to solve it. Some browsers give precedence to the element being focusable (and expose it in the accessibility tree) while some give precedence to the aria-hidden attribute (and hide the element).

Visible

Content perceivable through sight.

Content is considered visible if making it fully transparent would result in a difference in the pixels rendered for any part of the document that is currently within the viewport or can be brought into the viewport via scrolling.

Content is defined in WCAG.

Examples for Visible

Note: The examples presented here are non-normative and not testable. They serve to illustrate some common pitfalls about the definition and to help the implementers of ACT rules understand it.

This span element is visible (by default, elements are visible).

<span>Now you can see me!</span>

This span element is not visible because of the CSS visibility property.

<span style="visibility: hidden">I'm the invisible man</span>

This span element is not visible because of the CSS display property.

<span style="display: none">I'm the invisible man</span>

This span element is not visible because it is positioned off-screen

<span style="position: absolute; top: -9999px; left: -9999px;">Incredible how you can</span>

This span element is not visible because it contains only whitespace and line breaks.

<span>
	<br />
	&nbsp;
</span>

This span element is not visible because it has the exact same color as its background.

<span style="color: #00F; background: #00F;">See right through me</span>

Useful Links


Implementations

This section is not part of the official rule. It is populated dynamically and not accounted for in the change history or the last modified date. This section will not be included in the rule when it is published on the W3C website.

ToolConsitencyCompleteReport
AlfaconsistentYesView Report
axe-coreconsistentYesView Report
SortSiteconsistentYesView Report

Acknowledgments

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