register_hooks();
}
return self::$instance;
}
/**
* Register hooks based on active settings.
*/
private function register_hooks() {
if ( is_admin() ) {
return;
}
$settings = get_option( 'wpag_settings', wpag_default_settings() );
if ( ! empty( $settings['auto_fix_skip_link'] ) ) {
add_action( 'wp_body_open', array( $this, 'inject_skip_link' ), 1 );
add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_skip_link_css' ) );
}
if ( ! empty( $settings['auto_fix_lang_attr'] ) ) {
add_filter( 'language_attributes', array( $this, 'ensure_lang_attr' ) );
}
if ( ! empty( $settings['auto_fix_empty_headings'] ) ) {
add_filter( 'the_content', array( $this, 'fix_empty_headings' ), 999 );
}
if ( ! empty( $settings['auto_fix_form_labels'] ) ) {
add_filter( 'the_content', array( $this, 'fix_form_labels' ), 999 );
}
}
/**
* Inject skip-to-content link after .
*/
public function inject_skip_link() {
// Avoid duplicate if Pojo Accessibility is active.
if ( function_exists( 'is_plugin_active' ) && is_plugin_active( 'pojo-accessibility/pojo-accessibility.php' ) ) {
return;
}
echo ''
. esc_html__( 'Skip to content', 'accessibility-guard' )
. '';
}
/**
* Enqueue skip link CSS using wp_add_inline_style.
*/
public function enqueue_skip_link_css() {
wp_register_style( 'wpag-skip-link', false, array(), '1.0.0' );
wp_enqueue_style( 'wpag-skip-link' );
wp_add_inline_style( 'wpag-skip-link',
'.wpag-skip-link {
position: absolute;
top: -100%;
left: 0;
z-index: 999999;
padding: 8px 16px;
background: #000;
color: #fff;
text-decoration: none;
font-size: 14px;
line-height: 1.5;
clip: rect(1px, 1px, 1px, 1px);
clip-path: inset(50%);
overflow: hidden;
white-space: nowrap;
width: 1px;
height: 1px;
}
.wpag-skip-link:focus {
position: fixed;
top: 6px;
left: 6px;
clip: auto;
clip-path: none;
width: auto;
height: auto;
overflow: visible;
outline: 2px solid #0073aa;
outline-offset: 2px;
border-radius: 3px;
}'
);
}
/**
* Ensure the HTML element has a lang attribute.
*
* @param string $attributes Existing language attributes string.
* @return string
*/
public function ensure_lang_attr( $attributes ) {
if ( strpos( $attributes, 'lang=' ) !== false ) {
return $attributes;
}
$lang = get_bloginfo( 'language' );
if ( $lang ) {
$attributes .= ' lang="' . esc_attr( $lang ) . '"';
}
return $attributes;
}
/**
* Remove empty heading elements from content.
*
* @param string $content Post content.
* @return string
*/
public function fix_empty_headings( $content ) {
if ( empty( $content ) ) {
return $content;
}
// Remove empty headings: ,
,
etc.
$content = preg_replace(
'/]*>\s*( |\xC2\xA0)?\s*<\/h\1>/i',
'',
$content
);
return $content;
}
/**
* Add labels to unlabeled form fields in content.
*
* @param string $content Post content.
* @return string
*/
public function fix_form_labels( $content ) {
if ( empty( $content ) || strpos( $content, 'loadHTML(
'' . $content . '
',
LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD
);
libxml_clear_errors();
$xpath = new DOMXPath( $dom );
$fields = $xpath->query( '//input[not(@type="hidden") and not(@type="submit") and not(@type="button") and not(@type="image") and not(@type="reset")]|//select|//textarea' );
$changed = false;
foreach ( $fields as $field ) {
// Skip if already has label association.
if ( $field->hasAttribute( 'aria-label' ) || $field->hasAttribute( 'aria-labelledby' ) ) {
continue;
}
$id = $field->getAttribute( 'id' );
if ( $id ) {
$safe_id = str_replace( array( '"', "'", '\\' ), '', $id );
$label = $xpath->query( '//label[@for="' . $safe_id . '"]' );
if ( $label->length > 0 ) {
continue;
}
}
// Check if wrapped in label.
$parent = $field->parentNode;
$in_label = false;
while ( $parent ) {
if ( $parent->nodeName === 'label' ) {
$in_label = true;
break;
}
$parent = $parent->parentNode;
}
if ( $in_label ) {
continue;
}
if ( $field->hasAttribute( 'title' ) ) {
continue;
}
// Determine label text.
$label_text = '';
if ( $field->hasAttribute( 'placeholder' ) ) {
$label_text = $field->getAttribute( 'placeholder' );
} elseif ( $field->hasAttribute( 'name' ) ) {
$label_text = ucwords( str_replace( array( '_', '-', '[]' ), array( ' ', ' ', '' ), $field->getAttribute( 'name' ) ) );
}
if ( ! $label_text ) {
continue;
}
// Ensure the field has an ID.
if ( ! $id ) {
$id = 'wpag-field-' . wp_rand( 1000, 9999 );
$field->setAttribute( 'id', $id );
}
// Create label element.
$label_el = $dom->createElement( 'label' );
$label_el->setAttribute( 'for', $id );
$label_el->setAttribute( 'class', 'wpag-auto-label screen-reader-text' );
$label_el->textContent = $label_text;
$field->parentNode->insertBefore( $label_el, $field );
$changed = true;
}
if ( ! $changed ) {
return $content;
}
// Extract content from wrapper div.
$wrapper = $dom->getElementById( 'wpag-wrap' );
if ( ! $wrapper ) {
return $content;
}
$html = '';
foreach ( $wrapper->childNodes as $child ) {
$html .= $dom->saveHTML( $child );
}
return $html;
}
}