On Lightbox and issues with no-image files

[DanieleB]

Hello.

I’ve been running into some troubles while implementing Lightbox on a site (Berlin theme), because of the problem pointed out by @jflatnes in

Revised Lightbox Instructions

All of these altered examples look like they’re going to run into trouble if and when you have multiple files on an item, as both item_image_gallery and files_for_item print every file, not just the current one.

After some attempts, I might have found a clean solution; here it is, for those who might need it.

1. First, I declare a custom function:

function addLightbox($item_image_gallery, $filter = array()) 
{
	if ($item_image_gallery == '' || empty($filter)) return $item_image_gallery;
	
	// extracts all hrefs and edit them if needed
	$pattern = '~(<a(.*?)(href=[\'"]([^\'"]+)[\'"])(.*?)>)~';
	return preg_replace_callback(
		$pattern, 
		function ($matches) use ($filter) {
			// searches for extension in href's url
			$url_chunks = explode('.', $matches[3]);
			if (count($url_chunks) > 0) {
				// retrieves file extension, trimming it up
				$file_extension = substr(strtolower($url_chunks[count($url_chunks) -1]), 0, -1);
				// checks whether file extension is in filter array
				if (in_array($file_extension, $filter)) {
					return '<a ' . $matches[3] . ' data-lightbox="lightbox">';
				} else {
					return $matches[1];
				}
			} else {
				return $matches[1];
			}
		},
		$item_image_gallery
	);

2. Then, I pass item_image_gallery as first parameter to addLightbox custom function, the second parameter being the array of extensions accepted:

echo addLightbox(item_image_gallery(), array('jpeg', 'jpg', 'gif', 'png'));

Please note: the function does not check whether there’s any other content in the anchor tag, but it works if needed only for applying Lightbox feature.

Hope this helps.