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a11y-valid-aria-values

Static ARIA values must match their WAI-ARIA 1.2 grammar.
Package
Core
Category
Accessibility
Default severity
error by default
Auto-fix
Manual fix

#Why

ARIA uses defined boolean, tristate, token, token-list, integer, number, ID reference, ID-reference-list, and string grammars. Invalid values are ignored or mapped to a fallback state by user agents.

Static validation also enforces property-specific integer domains, including -1 for unknown row/column/set counts, one-based indexes and levels, and zero as the special aria-rowspan value. Numeric values must be finite. Integer grammar is lexical rather than machine-sized: an optional sign and leading zeroes are accepted, and very large valid integers do not overflow the validator.

#Examples

#Bad

<div aria-busy="yes"></div>

<div aria-level="0"></div>

<div aria-valuenow="NaN"></div>

#Good

<div aria-busy="true"></div>

<div aria-level="2"></div>

<div aria-level="+002"></div>

<div aria-valuenow="12.5"></div>

<div :aria-valuenow="currentValue"></div>

<div x-bind:aria-expanded="open"></div>

<div wire:bind:aria-expanded="open"></div>

Dynamic values are not checked, including Alpine x-bind: and Livewire wire:bind: attributes. A zero-length optional property is treated like an absent property, as required by WAI-ARIA 1.2. An empty required property still produces a required-property finding.

#References