1<?php
  2/**
  3 * WP_Classic_To_Block_Menu_Converter class
  4 *
  5 * @package WordPress
  6 * @since 6.3.0
  7 */
  8
  9/**
 10 * Converts a Classic Menu to Block Menu blocks.
 11 *
 12 * @since 6.3.0
 13 */
 14class WP_Classic_To_Block_Menu_Converter {
 15
 16	/**
 17	 * Converts a Classic Menu to blocks.
 18	 *
 19	 * @since 6.3.0
 20	 *
 21	 * @param WP_Term $menu The Menu term object of the menu to convert.
 22	 * @return string|WP_Error The serialized and normalized parsed blocks on success,
 23	 *                         an empty string when there are no menus to convert,
 24	 *                         or WP_Error on invalid menu.
 25	 */
 26	public static function convert( $menu ) {
 27
 28		if ( ! is_nav_menu( $menu ) ) {
 29			return new WP_Error(
 30				'invalid_menu',
 31				__( 'The menu provided is not a valid menu.' )
 32			);
 33		}
 34
 35		$menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) );
 36
 37		if ( empty( $menu_items ) ) {
 38			return '';
 39		}
 40
 41		// Set up the $menu_item variables.
 42		// Adds the class property classes for the current context, if applicable.
 43		_wp_menu_item_classes_by_context( $menu_items );
 44
 45		$menu_items_by_parent_id = static::group_by_parent_id( $menu_items );
 46
 47		$first_menu_item = isset( $menu_items_by_parent_id[0] )
 48			? $menu_items_by_parent_id[0]
 49			: array();
 50
 51		$inner_blocks = static::to_blocks(
 52			$first_menu_item,
 53			$menu_items_by_parent_id
 54		);
 55
 56		return serialize_blocks( $inner_blocks );
 57	}
 58
 59	/**
 60	 * Returns an array of menu items grouped by the id of the parent menu item.
 61	 *
 62	 * @since 6.3.0
 63	 *
 64	 * @param array $menu_items An array of menu items.
 65	 * @return array
 66	 */
 67	private static function group_by_parent_id( $menu_items ) {
 68		$menu_items_by_parent_id = array();
 69
 70		foreach ( $menu_items as $menu_item ) {
 71			$menu_items_by_parent_id[ $menu_item->menu_item_parent ][] = $menu_item;
 72		}
 73
 74		return $menu_items_by_parent_id;
 75	}
 76
 77	/**
 78	 * Turns menu item data into a nested array of parsed blocks
 79	 *
 80	 * @since 6.3.0
 81	 *
 82	 * @param array $menu_items              An array of menu items that represent
 83	 *                                       an individual level of a menu.
 84	 * @param array $menu_items_by_parent_id An array keyed by the id of the
 85	 *                                       parent menu where each element is an
 86	 *                                       array of menu items that belong to
 87	 *                                       that parent.
 88	 * @return array An array of parsed block data.
 89	 */
 90	private static function to_blocks( $menu_items, $menu_items_by_parent_id ) {
 91
 92		if ( empty( $menu_items ) ) {
 93			return array();
 94		}
 95
 96		$blocks = array();
 97
 98		foreach ( $menu_items as $menu_item ) {
 99			$class_name       = ! empty( $menu_item->classes ) ? implode( ' ', (array) $menu_item->classes ) : null;
100			$id               = ( null !== $menu_item->object_id && 'custom' !== $menu_item->object ) ? $menu_item->object_id : null;
101			$opens_in_new_tab = null !== $menu_item->target && '_blank' === $menu_item->target;
102			$rel              = ( null !== $menu_item->xfn && '' !== $menu_item->xfn ) ? $menu_item->xfn : null;
103			$kind             = null !== $menu_item->type ? str_replace( '_', '-', $menu_item->type ) : 'custom';
104
105			$block = array(
106				'blockName' => isset( $menu_items_by_parent_id[ $menu_item->ID ] ) ? 'core/navigation-submenu' : 'core/navigation-link',
107				'attrs'     => array(
108					'className'     => $class_name,
109					'description'   => $menu_item->description,
110					'id'            => $id,
111					'kind'          => $kind,
112					'label'         => $menu_item->title,
113					'opensInNewTab' => $opens_in_new_tab,
114					'rel'           => $rel,
115					'title'         => $menu_item->attr_title,
116					'type'          => $menu_item->object,
117					'url'           => $menu_item->url,
118				),
119			);
120
121			$block['innerBlocks']  = isset( $menu_items_by_parent_id[ $menu_item->ID ] )
122			? static::to_blocks( $menu_items_by_parent_id[ $menu_item->ID ], $menu_items_by_parent_id )
123			: array();
124			$block['innerContent'] = array_map( 'serialize_block', $block['innerBlocks'] );
125
126			$blocks[] = $block;
127		}
128
129		return $blocks;
130	}
131}
132