woocommerce/includes/admin/meta-boxes/class-wc-meta-box-product-images.php

<?php
/**
 * Product Images
 *
 * Display the product images meta box.
 *
 * @author      WooThemes
 * @category    Admin
 * @package     WooCommerce/Admin/Meta Boxes
 * @version     2.1.0
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

/**
 * WC_Meta_Box_Product_Images Class.
 */
class WC_Meta_Box_Product_Images {

	/**
	 * Output the metabox.
	 *
	 * @param WP_Post $post
	 */
	public static function output( $post ) {
		global $thepostid, $product_object;

		$thepostid      = $post->ID;
		$product_object = $thepostid ? wc_get_product( $thepostid ) : new WC_Product;
		wp_nonce_field( 'woocommerce_save_data', 'woocommerce_meta_nonce' );
		?>
		<div id="product_images_container">
			<ul class="product_images">
				<?php
					$product_image_gallery = $product_object->get_gallery_image_ids( 'edit' );

					$attachments         = array_filter( $product_image_gallery );
					$update_meta         = false;
					$updated_gallery_ids = array();

					if ( ! empty( $attachments ) ) {
						foreach ( $attachments as $attachment_id ) {
							$attachment = wp_get_attachment_image( $attachment_id, 'thumbnail' );

							// if attachment is empty skip
							if ( empty( $attachment ) ) {
								$update_meta = true;
								continue;
							}

							echo '<li class="image" data-attachment_id="' . esc_attr( $attachment_id ) . '">
								' . $attachment . '
								<ul class="actions">
									<li><a href="#" class="delete tips" data-tip="' . esc_attr__( 'Delete image', 'woocommerce' ) . '">' . __( 'Delete', 'woocommerce' ) . '</a></li>
								</ul>
							</li>';

							// rebuild ids to be saved
							$updated_gallery_ids[] = $attachment_id;
						}

						// need to update product meta to set new gallery ids
						if ( $update_meta ) {
							update_post_meta( $post->ID, '_product_image_gallery', implode( ',', $updated_gallery_ids ) );
						}
					}
				?>
			</ul>

			<input type="hidden" id="product_image_gallery" name="product_image_gallery" value="<?php echo esc_attr( $product_image_gallery ); ?>" />

		</div>
		<p class="add_product_images hide-if-no-js">
			<a href="#" data-choose="<?php esc_attr_e( 'Add images to product gallery', 'woocommerce' ); ?>" data-update="<?php esc_attr_e( 'Add to gallery', 'woocommerce' ); ?>" data-delete="<?php esc_attr_e( 'Delete image', 'woocommerce' ); ?>" data-text="<?php esc_attr_e( 'Delete', 'woocommerce' ); ?>"><?php _e( 'Add product gallery images', 'woocommerce' ); ?></a>
		</p>
		<?php
	}

	/**
	 * Save meta box data.
	 *
	 * @param int $post_id
	 * @param WP_Post $post
	 */
	public static function save( $post_id, $post ) {
		$product_type   = empty( $_POST['product-type'] ) ? WC_Product_Factory::get_product_type( $post_id ) : sanitize_title( stripslashes( $_POST['product-type'] ) );
		$classname      = WC_Product_Factory::get_product_classname( $post_id, $product_type ? $product_type : 'simple' );
		$product        = new $classname( $post_id );
		$attachment_ids = isset( $_POST['product_image_gallery'] ) ? array_filter( explode( ',', wc_clean( $_POST['product_image_gallery'] ) ) ) : array();

		$product->set_gallery_image_ids( $attachment_ids );
		$product->save();
	}
}