Background image

Hi,

I added support for background image credits to your plugin. I also added display of the image title. However, I did not add any admin ui.

Feel free to add the code or parts of it to your plugin.

function get_image_credits() {
		global $post;
		$attachment_ids = array();
		$credits = array();
		$header_id = NULL;
		$background_id = NULL;

		// First first check background image
		$query_images = new WP_Query( array(
			'post_type' => 'attachment',
			'post_status' => 'inherit',
			'meta_key' => '_wp_attachment_is_custom_background',
			'meta_value' => get_option('stylesheet') ) );
		//$query_images->get_posts();
		foreach ( $query_images->posts as $image ) {
			if ( get_background_image() != $image->guid ) continue;
			$background_id = $image->ID;
        		$attachment_ids[] = $background_id;
			break;
		}

		// First check for post thumbnail and save its ID in an array
		if (function_exists('has_post_thumbnail') && has_post_thumbnail($post->ID)) {
			$header_id = get_post_thumbnail_id($post->ID);
			$attachment_ids[] = $header_id;
		}

		// Next look in post content and check for instances of wp-image-[digits]
		if (preg_match_all('/wp-image-(\d+)/i', $post->post_content, $matches)) {
			foreach ($matches[1] as $id) {
				if (!in_array($id, $attachment_ids)) {
					$attachment_ids[] = $id;
				}
			}
		}

		// Go through all our attachments IDs and generate credits
		foreach ($attachment_ids as $id) {
			// Add names
			$credit_source = esc_attr(get_post_meta($id, '_wp_attachment_source_name', true));
			if (empty($credit_source)) continue; // Nobody to credit

			$credit_text = '';
			if(get_the_title($id) != '') $credit_text .= esc_attr(get_the_title($id)) .': ';
			$credit_text .= $credit_source;

			// Maybe add if its header or background image
			$usage = array();
			if($id == $background_id) $usage[] = __( 'Background Image' );
			if($id == $header_id) $usage[] = __( 'Header Image' );
			if(!empty($usage)) $credit_text .= ' (' . implode($usage, ', ') . ')';

			$credit_link = esc_url(get_post_meta($id, '_wp_attachment_source_url', true));

			if (empty($credit_link)) {
				$credits[] = $credit_text;
			} else {
				$credits[] = '<a href="' . $credit_link . '">' . $credit_text . '</a>';
			}
		}

		return array_unique($credits);
	}