Source
File: wp-admin/includes/class-walker-nav-menu-checklist.php
public function start_el( &$output, $item, $depth = 0, $args = null, $id = 0 ) {
global $_nav_menu_placeholder, $nav_menu_selected_id;
$_nav_menu_placeholder = ( 0 > $_nav_menu_placeholder ) ? intval( $_nav_menu_placeholder ) - 1 : -1;
$possible_object_id = isset( $item->post_type ) && 'nav_menu_item' === $item->post_type ? $item->object_id : $_nav_menu_placeholder;
$possible_db_id = ( ! empty( $item->ID ) ) && ( 0 < $possible_object_id ) ? (int) $item->ID : 0;
$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
$output .= $indent . '<li>';
$output .= '<label class="menu-item-title">';
$output .= '<input type="checkbox"' . wp_nav_menu_disabled_check( $nav_menu_selected_id, false ) . ' class="menu-item-checkbox';
if ( ! empty( $item->front_or_home ) ) {
$output .= ' add-to-top';
}
$output .= '" name="menu-item[' . $possible_object_id . '][menu-item-object-id]" value="' . esc_attr( $item->object_id ) . '" /> ';
if ( ! empty( $item->label ) ) {
$title = $item->label;
} elseif ( isset( $item->post_type ) ) {
/** This filter is documented in wp-includes/post-template.php */
$title = apply_filters( 'the_title', $item->post_title, $item->ID );
}
$output .= isset( $title ) ? esc_html( $title ) : esc_html( $item->title );
if ( empty( $item->label ) && isset( $item->post_type ) && 'page' === $item->post_type ) {
// Append post states.
$output .= _post_states( $item, false );
}
$output .= '</label>';
// Menu item hidden fields.
$output .= '<input type="hidden" class="menu-item-db-id" name="menu-item[' . $possible_object_id . '][menu-item-db-id]" value="' . $possible_db_id . '" />';
$output .= '<input type="hidden" class="menu-item-object" name="menu-item[' . $possible_object_id . '][menu-item-object]" value="' . esc_attr( $item->object ) . '" />';
$output .= '<input type="hidden" class="menu-item-parent-id" name="menu-item[' . $possible_object_id . '][menu-item-parent-id]" value="' . esc_attr( $item->menu_item_parent ) . '" />';
$output .= '<input type="hidden" class="menu-item-type" name="menu-item[' . $possible_object_id . '][menu-item-type]" value="' . esc_attr( $item->type ) . '" />';
$output .= '<input type="hidden" class="menu-item-title" name="menu-item[' . $possible_object_id . '][menu-item-title]" value="' . esc_attr( $item->title ) . '" />';
$output .= '<input type="hidden" class="menu-item-url" name="menu-item[' . $possible_object_id . '][menu-item-url]" value="' . esc_attr( $item->url ) . '" />';
$output .= '<input type="hidden" class="menu-item-target" name="menu-item[' . $possible_object_id . '][menu-item-target]" value="' . esc_attr( $item->target ) . '" />';
$output .= '<input type="hidden" class="menu-item-attr-title" name="menu-item[' . $possible_object_id . '][menu-item-attr-title]" value="' . esc_attr( $item->attr_title ) . '" />';
$output .= '<input type="hidden" class="menu-item-classes" name="menu-item[' . $possible_object_id . '][menu-item-classes]" value="' . esc_attr( implode( ' ', $item->classes ) ) . '" />';
$output .= '<input type="hidden" class="menu-item-xfn" name="menu-item[' . $possible_object_id . '][menu-item-xfn]" value="' . esc_attr( $item->xfn ) . '" />';
}