Envira Gallery Lite Shortcode

function shortcode( $atts ) {

		if ( is_admin() ) {
			return;
		}
		global $post;

		// If no attributes have been passed, the gallery should be pulled from the current post.
		$gallery_id = false;
		if ( empty( $atts ) ) {
			$gallery_id = $post->ID;
			$data       = is_preview() ? $this->base->_get_gallery( $gallery_id ) : $this->base->get_gallery( $gallery_id );
		} elseif ( isset( $atts['id'] ) ) {
			$gallery_id = (int) $atts['id'];
			$data       = is_preview() ? $this->base->_get_gallery( $gallery_id ) : $this->base->get_gallery( $gallery_id );
		} elseif ( isset( $atts['slug'] ) ) {
			$gallery_id = $atts['slug'];
			$data       = is_preview() ? $this->base->_get_gallery_by_slug( $gallery_id ) : $this->base->get_gallery_by_slug( $gallery_id );
		} else {
			// A custom attribute must have been passed. Allow it to be filtered to grab data from a custom source.
			$data       = apply_filters( 'envira_gallery_custom_gallery_data', false, $atts, $post );
			$gallery_id = $data['config']['id'];
		}

		// Change the gallery order, if specified.
		$data = $this->maybe_sort_gallery( $data, $gallery_id );

		// Limit the number of images returned, if specified.
		// [envira-gallery id="123" limit="10"] would only display 10 images.
		if ( isset( $atts['limit'] ) && is_numeric( $atts['limit'] ) ) {
			$images          = $data['gallery'];
			$images          = array_slice( $data['gallery'], 0, absint( $atts['limit'] ), true );
			$data['gallery'] = $images;
		}

		// Allow the data to be filtered before it is stored and used to create the gallery output.
		$data = apply_filters( 'envira_gallery_pre_data', $data, $gallery_id );

		// If there is no data to output or the gallery is inactive, do nothing.
		if ( ! $data || empty( $data['gallery'] ) || isset( $data['status'] ) && 'inactive' === $data['status'] && ! is_preview() ) {
			return;
		}

		$this->gallery_data = $data;

		// Get rid of any external plugins trying to jack up our stuff where a gallery is present.
		$this->plugin_humility();

		// Prepare variables.
		$this->data[ $data['id'] ]  = $this->gallery_data;
		$this->index[ $data['id'] ] = [];
		$gallery                    = '';
		$i                          = 1;

		// If this is a feed view, customize the output and return early.
		if ( is_feed() ) {
			return $this->do_feed_output( $data );
		}

		$lazy_loading_delay = isset( $this->gallery_data['config']['lazy_loading_delay'] ) ? intval( $this->gallery_data['config']['lazy_loading_delay'] ) : 500;

		// Load scripts and styles.
		wp_enqueue_style( $this->base->plugin_slug . '-style' );
		wp_enqueue_style( $this->base->plugin_slug . '-lazyload' );
		wp_enqueue_style( $this->base->plugin_slug . '-fancybox' );
		wp_enqueue_style( $this->base->plugin_slug . '-jgallery' );
		wp_enqueue_script( 'jquery-masonry' );
		wp_enqueue_script( $this->base->plugin_slug . '-script' );
		// If lazy load is active, load the lazy load script.
		if ( $this->get_config( 'lazy_loading', $data ) === 1 ) {
			wp_localize_script( $this->base->plugin_slug . '-script', 'envira_lazy_load', [ 'true' ] );
			wp_localize_script( $this->base->plugin_slug . '-script', 'envira_lazy_load_initial', [ 'false' ] );
			wp_localize_script( $this->base->plugin_slug . '-script', 'envira_lazy_load_delay', [ (string) $lazy_loading_delay ] );
		}

		// Load custom gallery themes if necessary.
		if ( 'base' !== $this->get_config( 'gallery_theme', $this->gallery_data ) && $this->get_config( 'columns', $this->gallery_data ) > 0 ) {
			// if columns is zero, then it's automattic which means we do not load gallery themes because it will mess up the new javascript layout.
			$this->load_gallery_theme( $this->get_config( 'gallery_theme', $this->gallery_data ) );
		}

		// Load custom lightbox themes if necessary.
		if ( 'base' !== $this->get_config( 'lightbox_theme', $this->gallery_data ) ) {
			$this->load_lightbox_theme( $this->get_config( 'lightbox_theme', $this->gallery_data ) );
		}

		// Load gallery init code in the footer.
		add_action( 'wp_footer', [ $this, 'gallery_init' ], 1000 );

		// Run a hook before the gallery output begins but after scripts and inits have been set.
		do_action( 'envira_gallery_before_output', $this->gallery_data );

		// Apply a filter before starting the gallery HTML.
		$gallery = apply_filters( 'envira_gallery_output_start', $gallery, $this->gallery_data );

		// Build out the gallery HTML.
		$gallery    .= '<div id="envira-gallery-wrap-' . sanitize_html_class( $this->gallery_data['id'] ) . '" class="' . $this->get_gallery_classes( $this->gallery_data ) . '" itemscope itemtype="https://schema.org/ImageGallery">';
			$gallery = apply_filters( 'envira_gallery_output_before_container', $gallery, $this->gallery_data );

		// Description.
		if ( isset( $this->gallery_data['config']['description_position'] ) && 'above' === $this->gallery_data['config']['description_position'] ) {
			$gallery = $this->description( $gallery, $this->gallery_data );
		}

			$opacity_insert = false;
		if ( $this->get_config( 'columns', $this->gallery_data ) === 0 ) {
			$opacity_insert = ' style="opacity: 0.0" ';
		}

			// add justified CSS?
			$extra_css               = 'envira-gallery-justified-public';
			$row_height              = false;
			$justified_gallery_theme = false;
		if ( $this->get_config( 'columns', $this->gallery_data ) > 0 ) {
			$extra_css = false;
		} else {
			$row_height              = $this->get_config( 'justified_row_height', $this->gallery_data );
			$justified_gallery_theme = $this->get_config( 'justified_gallery_theme', $this->gallery_data );
		}

			$gallery .= '<div' . $opacity_insert . ' data-row-height="' . $row_height . '" data-gallery-theme="' . $justified_gallery_theme . '" id="envira-gallery-' . sanitize_html_class( $this->gallery_data['id'] ) . '" class="envira-gallery-public ' . $extra_css . ' envira-gallery-' . sanitize_html_class( $this->get_config( 'columns', $this->gallery_data ) ) . '-columns envira-clear' . ( $this->get_config( 'isotope', $this->gallery_data ) ? ' enviratope' : '' ) . ( $this->get_config( 'css_animations', $this->gallery_data ) ? ' envira-gallery-css-animations' : '' ) . '" data-envira-columns="' . $this->get_config( 'columns', $this->gallery_data ) . '">';

				// Start image loop.
		foreach ( $data['gallery'] as $id => $item ) {

			// Add the gallery item to the markup.
			$gallery = $this->generate_gallery_item_markup( $gallery, $this->gallery_data, $item, $id, $i );

			// Increment the iterator.
			$i++;

		}
				// End image loop.

			$gallery .= '</div>';
			// Description.
		if ( isset( $this->gallery_data['config']['description_position'] ) && 'below' === $this->gallery_data['config']['description_position'] ) {
			$gallery = $this->description( $gallery, $this->gallery_data );
		}

			$gallery = apply_filters( 'envira_gallery_output_after_container', $gallery, $this->gallery_data );

		$gallery .= '</div>';
		$gallery  = apply_filters( 'envira_gallery_output_end', $gallery, $this->gallery_data );

		// Increment the counter.
		$this->counter++;

		// Remove any contextual filters so they don't affect other galleries on the page.
		if ( $this->get_config( 'mobile', $this->gallery_data ) ) {
			remove_filter( 'envira_gallery_output_image_attr', [ $this, 'mobile_image' ], 999, 4 );
		}

		// Add no JS fallback support.
		$no_js    = '<noscript>';
		$no_js   .= $this->get_indexable_images( $this->gallery_data['id'] );
		$no_js   .= '</noscript>';
		$gallery .= $no_js;

		// Return the gallery HTML.
		return apply_filters( 'envira_gallery_output', $gallery, $this->gallery_data );

	}