, a wrapping , aria-label, aria-labelledby or * title. Buttons and hidden/submit/reset/image inputs are handled elsewhere. */ final class FormControlLabelRule implements Rule { private const EXEMPT_INPUT_TYPES = array( 'hidden', 'submit', 'button', 'reset', 'image' ); /** * Returns the stable rule identifier. * * @return string */ public function id(): string { return 'form-control-label'; } /** * Returns the WCAG success criterion this rule maps to. * * @return string */ public function wcag(): string { return '1.3.1'; } /** * Evaluates form controls and flags any without an accessible name. * * @param DOMDocument $dom Parsed document. * @param DOMXPath $xpath XPath helper for the document. * @param array $context Optional scan context. * @return list */ public function evaluate( DOMDocument $dom, DOMXPath $xpath, array $context = array() ): array { $issues = array(); $labelled = $this->labelledIds( $xpath ); foreach ( $xpath->query( '//input | //select | //textarea' ) as $control ) { if ( ! $control instanceof DOMElement ) { continue; } if ( 'input' === strtolower( $control->nodeName ) && $this->isExemptInput( $control ) ) { continue; } if ( $this->hasAccessibleName( $control, $xpath, $labelled ) ) { continue; } $issues[] = new Issue( ruleId: $this->id(), wcag: $this->wcag(), severity: Severity::Error, message: __( 'Form control has no associated label.', 'a11yfleet' ), context: $this->snippet( $control ), howToFix: __( 'Add a tied to the field by id, wrap the field in a , or add an aria-label / aria-labelledby.', 'a11yfleet' ), ); } return $issues; } /** * Collects the set of ids referenced by elements. * * @param DOMXPath $xpath XPath helper for the document. * @return array */ private function labelledIds( DOMXPath $xpath ): array { $ids = array(); foreach ( $xpath->query( '//label[@for]' ) as $label ) { if ( ! $label instanceof DOMElement ) { continue; } $for = trim( $label->getAttribute( 'for' ) ); if ( '' !== $for ) { $ids[ $for ] = true; } } return $ids; } /** * Determines whether an input type is exempt from labelling here. * * @param DOMElement $input Input element to inspect. * @return bool */ private function isExemptInput( DOMElement $input ): bool { $type = strtolower( trim( $input->getAttribute( 'type' ) ) ); return in_array( $type, self::EXEMPT_INPUT_TYPES, true ); } /** * Determines whether a control has any accessible name. * * @param DOMElement $control Form control element. * @param DOMXPath $xpath XPath helper for the document. * @param array $labelled Set of ids referenced by labels. * @return bool */ private function hasAccessibleName( DOMElement $control, DOMXPath $xpath, array $labelled ): bool { if ( '' !== trim( $control->getAttribute( 'aria-label' ) ) ) { return true; } if ( '' !== trim( $control->getAttribute( 'aria-labelledby' ) ) ) { return true; } if ( '' !== trim( $control->getAttribute( 'title' ) ) ) { return true; } $id = trim( $control->getAttribute( 'id' ) ); if ( '' !== $id && isset( $labelled[ $id ] ) ) { return true; } $ancestorLabels = $xpath->query( 'ancestor::label', $control ); return $ancestorLabels instanceof \DOMNodeList && $ancestorLabels->length > 0; } /** * Returns a short HTML snippet representing the control for reports. * * @param DOMElement $control Form control element. * @return string */ private function snippet( DOMElement $control ): string { $name = $control->getAttribute( 'name' ); return '<' . strtolower( $control->nodeName ) . ( '' !== $name ? ' name="' . $name . '"' : '' ) . '>'; } }