Developer guide

Architecture

On init (priority 20), when Enable Product Gallery is on, Free removes woocommerce_show_product_images from woocommerce_before_single_product_summary, adds its own renderer at priority 20, returns false for WooCommerce's zoom, PhotoSwipe and FlexSlider filters, and filters the woocommerce/product-image-gallery block output. Pro extends Free only through hooks: it swaps the template for the selected style and, when licensed, loads its own assets instead of Free's.

Rendering the gallery

siteryn_pgz_product_gallery( int $product_id = 0 ): void // 0 = current product

The template tag and [siteryn_pgz_gallery] render the markup but don't load assets; Free enqueues its CSS and JS only on single product pages. Elsewhere, enqueue them yourself:

\Siteryn\SiterynProductGalleryZoom\Assets::enqueue_gallery_assets();
siteryn_pgz_product_gallery( 123 ); // or echo do_shortcode( '[siteryn_pgz_gallery id="123"]' );

// Pro (licensed): style shortcodes enqueue their own assets and accept Free settings as attributes.
echo do_shortcode( '[siteryn_pgz_pro_grid id="123" main_image_fit="cover" zoom_mode="lens"]' );

A Pro style rendered through Free's path off a product page also needs \Siteryn\SiterynProductGalleryZoomPro\Assets::enqueue_style_assets( 'grid' ).

Useful public methods

Free classes live in Siteryn\SiterynProductGalleryZoom, Pro classes in Siteryn\SiterynProductGalleryZoomPro.

Templates

Copy templates/product-image.php from the Free plugin to your-theme/siteryn-product-gallery-zoom/product-image.php. It receives $product, $images and $settings. Keep the @version header: when the bundled copy has a newer version, administrators see "Siteryn Product Gallery template files should be updated".

id, alt,
full_src, full_srcset, full_sizes, full_width, full_height,   // main image (woocommerce_gallery_image_size)
thumb_src, thumb_width, thumb_height,                         // thumbnail (woocommerce_gallery_thumbnail_size)
lightbox_src, lightbox_width, lightbox_height                 // zoom & lightbox (woocommerce_gallery_full_size)

The product image comes first, then the gallery images, without duplicates. A product without images gets one placeholder item with id 0.

add_filter( 'siteryn_pgz_pro_style_templates', function ( $templates ) {
	$file = locate_template( 'siteryn-product-gallery-zoom-pro/style-grid.php' );
	if ( $file ) {
		$templates['grid'] = $file;
	}
	return $templates;
}, 20 );

Keep namespace Siteryn\SiterynProductGalleryZoomPro; at the top of the copy. The vertical-slider, vertical-scroll and multirow-slider templates also include a file from parts/; copy it alongside.

Markup contract

The script finds the gallery through these attributes; keep them in a template override.

JavaScript

• Script handle siteryn-pgz, in the footer, with no jQuery dependency; style handle siteryn-pgz (depends on dashicons). Minified files load unless SCRIPT_DEBUG is on.
• The only localized data is siterynPgz.i18n.counterFormat (%1$s / %2$s).
• There is no public JavaScript API and no custom events. Galleries initialise once, on DOMContentLoaded (or straight away if the page has already loaded).
• To go to an image, click its thumbnail: gallery.querySelector('.siteryn-pgz-gallery__thumb[data-index="2"]').click().
• Variation switching listens to WooCommerce's found_variation and reset_data events (needs jQuery) on the page's first variations form.
• Galleries loaded later by AJAX (quick views) aren't initialised, and running the script again double-binds existing galleries.

CSS custom properties

Your settings are printed as an inline style on :root (tablet and mobile overrides in max-width: 782px and 480px media queries). Override them in your theme to restyle the gallery without a template.

The zoom layers the script adds are .siteryn-pgz-zoom-inner, .siteryn-pgz-zoom-lens and .siteryn-pgz-zoom-window (each .is-active while showing).

Data

update_post_meta( $product_id, '_siteryn_pgz_pro_videos', array(
	array( 'url' => 'https://www.youtube.com/watch?v=XXXXXXXXXXX', 'thumb_id' => 0 ),
	array( 'url' => 'https://example.com/media/demo.mp4', 'thumb_id' => 789 ),
) );

Video URLs can be self-hosted .mp4, .webm or .ogv files, or anything WordPress can embed. Settings keys are listed per tab on the feature pages; for example zoom_mode is none, inner, lens or window.

Uninstalling Free deletes its two options (on every site of a network). Uninstalling Pro deletes its options and license data; product videos are kept.

Endpoints

There are no REST routes, blocks or public AJAX actions. Admin endpoints require manage_woocommerce and a nonce:

wp_ajax_siteryn_deactivation_feedback (shared by Siteryn plugins) sends the optional deactivation survey; it requires activate_plugins and a nonce.

There are no cron events and no custom capabilities.

wp-config constants

Hooks and their examples are on Hooks & filters.