Lightbox Grouping

// group images for lightbox galleries (group-1, group-2 etc)
function handle_lightbox_groups_in_gallery_part(){
?>
<script>
(function($){
    $(window).on('load', function() {
			
        $('.lightbox-added').each(function(index, element){
          $('.group-'+index+' .lightbox-added').attr('data-group', index);
        });

        var groups = {};
        $('.lightbox-added').each(function() {
          var id = parseInt($(this).attr('data-group'), 10);
          if(!groups[id]) {
            groups[id] = [];
          }
          groups[id].push( this );
        });
		
        $.each(groups, function() {
          $(this).magnificPopup({
              type: 'image',
              mainClass: 'avia-popup mfp-zoom-in mfp-image-loaded',
              closeOnContentClick: false,
              closeBtnInside: false,
              gallery: { enabled:true }
          })
        });
    });
})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'handle_lightbox_groups_in_gallery_part');