'',
'sub_menu_button_toggle_class' => '',
'expand_text' => '',
'collapse_text' => '',
'icon' => null, // Optional.
'sub_menu_item_state_id' => 'navMenuItemExpanded',
);
/**
* AMP_Nav_Menu_Dropdown_Sanitizer constructor.
*
* @since 1.1.0
*
* @param DOMDocument $dom DOM.
* @param array $args Args.
*/
public function __construct( $dom, $args = array() ) {
parent::__construct( $dom, $args );
$this->args = self::ensure_defaults( $this->args );
}
/**
* Add filter to manipulate output during output buffering to add AMP-compatible dropdown toggles.
*
* @since 1.0
*
* @param array $args Args.
*/
public static function add_buffering_hooks( $args = array() ) {
if ( empty( $args['sub_menu_button_class'] ) || empty( $args['sub_menu_button_toggle_class'] ) ) {
return;
}
$args = self::ensure_defaults( $args );
/**
* Filter the HTML output of a nav menu item to add the AMP dropdown button to reveal the sub-menu.
*
* @param string $item_output Nav menu item HTML.
* @param object $item Nav menu item.
* @return string Modified nav menu item HTML.
*/
add_filter(
'walker_nav_menu_start_el',
function( $item_output, $item, $depth, $nav_menu_args ) use ( $args ) {
unset( $depth );
// Skip adding buttons to nav menu widgets for now.
if ( empty( $nav_menu_args->theme_location ) ) {
return $item_output;
}
if ( ! in_array( 'menu-item-has-children', $item->classes, true ) ) {
return $item_output;
}
static $nav_menu_item_number = 0;
$nav_menu_item_number++;
$expanded = in_array( 'current-menu-ancestor', $item->classes, true );
$expanded_state_id = $args['nav_menu_item_state_id'] . $nav_menu_item_number;
// Create new state for managing storing the whether the sub-menu is expanded.
$item_output .= sprintf(
'',
esc_attr( $expanded_state_id ),
wp_json_encode( $expanded )
);
$dropdown_button = '%s',
esc_attr( sprintf( "$expanded_state_id ? %s : %s", wp_json_encode( $args['collapse_text'] ), wp_json_encode( $args['expand_text'] ) ) ),
esc_html( $expanded ? $args['collapse_text'] : $args['expand_text'] )
);
}
$dropdown_button .= '';
$item_output .= $dropdown_button;
return $item_output;
},
10,
4
);
}
/**
* Method needs to be stubbed to fulfill base class requirements.
*
* @since 1.1.0
*/
public function sanitize() {
// Empty method body.
}
/**
* Ensure that some defaults are always set as fallback.
*
* @param array $args Arguments to set the defaults in as necessary.
* @return array Arguments with defaults filled.
*/
protected static function ensure_defaults( $args ) {
// Ensure accessibility labels are always set.
if ( empty( $args['expand_text'] ) ) {
$args['expand_text'] = __( 'expand child menu', 'amp' );
}
if ( empty( $args['collapse_text'] ) ) {
$args['collapse_text'] = __( 'collapse child menu', 'amp' );
}
// Ensure the state ID is always set.
if ( empty( $args['nav_menu_item_state_id'] ) ) {
$args['nav_menu_item_state_id'] = 'navMenuItemExpanded';
}
return $args;
}
}