singe-galleries.php(with isotope and photoswipe)

/*****
- This is a template used by 6 posts within a CPT
- Each post contains some text in the content editor and an ACF Gallery. 
- Each image is tagged with category(ies) using Enhanced Media Library plugin.
- The categories used on each page are being echoed out to provide a means to filter the images.
- The lightbox being used is http://photoswipe.com
- The filter is done with http://isotope.com
- Included with the Isotope integration is https://github.com/desandro/imagesloaded

Thanks to @kevinwhoffman for helping with the gallery filter. 
And to /susanlangenes for showing me how to access image sizes in the <figure>,
as well as providing the code for the photoswipe/isotope integration
*****/


<?php 

/*
	Template Name: (Single)Galleries Page
*/

 ?>

<?php get_header(); ?>


<?php if ( have_posts() ) while ( have_posts() ) : the_post(); ?>

 	<h1 class = "page-title"><?php the_title(); ?></h1>
 	
 		<!--add introduction from the content editor on each post-->
 		<div class="gallery-intro">
 		  
 			<?php the_content(); ?>
 			
 		</div> <!-- /gallery-intro -->

<!--output categories assigned to each photo via Enhanced Media Categories plugin. -->
	<div class="gallery-filter">
	        <ul id="filters">
	            <li><a href="#" data-filter="*" class="active buttonlink">All</a></li>
	            <?php
	                $images = get_field('images');
	                $image_terms = array();
	                $all_used_terms = array();
	                foreach( $images as $image ) {
	                	//loop over images and get which categories are being used
	                    $image_terms = wp_get_post_terms($image['ID'], 'media_category', array('fields' => 'slugs'));
	                    
	                    // get all categories and remove duplicates
	                    $all_used_terms = array_unique( array_merge( $all_used_terms, $image_terms ) );
	                }
	                foreach ( $all_used_terms as $term ) {
	                	//outputting slug so need to remove - and make first letter uppercase
	                	//must be .$term with the dot preceeding
	                	
	                	echo '<li><a href="#" class = "buttonlink" data-filter=".'.$term.'">' . ucwords(preg_replace('/-/', ' ', $term)) . '</a></li>';
	                    
	                }
	            ?>
	        </ul>
	</div><!-- /gallery-filter -->
	

 	<!--loop over all images available for post -->
 	<!--Images are part of an ACF Gallery - see documentation 
 	http://www.advancedcustomfields.com/resources/gallery/-->
 <div class="wrapper-gallery" itemscope itemtype="http://schema.org/ImageGallery">
  		<?php 
  		$images = get_field('images');
	
  		if( $images ) : ?>		
	        <?php foreach( $images as $image ) : 
	        	$terms = wp_get_object_terms($image['ID'], 'media_category');
	    	  ?>
	    	  
			<!--echo out the tagged category as a class and data-category in the figure-->

	              <figure class="gallery-image image-item <?php if($terms) { foreach ($terms as $term) { echo $term->slug . ' ';}}?>" 
        	    data-catagory="<?php if($terms) { foreach ($terms as $term) { echo $term->slug . ' ';}}	?>" itemprop="associatedMedia" itemscope itemtype="http://schema.org/ImageObject">
	                <a href="<?php echo $image['url']; ?>" itemprop="contentUrl" data-size="<?php echo $image['width'] . 'x' . $image['height']; ?>">
	               		 <img class="" src="<?php echo $image['sizes']['large']; ?>" itemprop="thumbnail" alt="<?php echo $image['alt']; ?>" />
	                </a>
	                <figcaption itemprop="caption description"><?php echo $image['caption']; ?></figcaption>                
	              </figure>
			        
	   		<?php endforeach; ?>		    
  		<?php endif; ?>
  		
 </div> <!-- gallery-wrapper -->
<?php endwhile; ?>

  	<?php next_post_link('%link', '<i class="fa fa-long-arrow-left"></i>'); ?>

  	<a href="<?php bloginfo('url'); ?>/?p=44"><i class="fa fa-th-large"></i></a>

  	<?php previous_post_link ('%link', '<i class="fa fa-long-arrow-right"></i>'); ?>




<!-- Photoswipe HTML.  Requried for the overlay. -->

<!-- Root element of PhotoSwipe. Must have class pswp. -->
<div class="pswp" tabindex="-1" role="dialog" aria-hidden="true">

    <!-- Background of PhotoSwipe. 
         It's a separate element, as animating opacity is faster than rgba(). -->
    <div class="pswp__bg"></div>

    <!-- Slides wrapper with overflow:hidden. -->
    <div class="pswp__scroll-wrap">

        <!-- Container that holds slides. PhotoSwipe keeps only 3 slides in DOM to save memory. -->
        <!-- don't modify these 3 pswp__item elements, data is added later on. -->
        <div class="pswp__container">
            <div class="pswp__item"></div>
            <div class="pswp__item"></div>
            <div class="pswp__item"></div>
        </div>

        <!-- Default (PhotoSwipeUI_Default) interface on top of sliding area. Can be changed. -->
        <div class="pswp__ui pswp__ui--hidden">

            <div class="pswp__top-bar">

                <!--  Controls are self-explanatory. Order can be changed. -->

                <div class="pswp__counter"></div>

                <button class="pswp__button pswp__button--close" title="Close (Esc)"></button>

                <button class="pswp__button pswp__button--share" title="Share"></button>

                <button class="pswp__button pswp__button--fs" title="Toggle fullscreen"></button>

                <button class="pswp__button pswp__button--zoom" title="Zoom in/out"></button>

                <!-- Preloader demo http://codepen.io/dimsemenov/pen/yyBWoR -->
                <!-- element will get class pswp__preloader--active when preloader is running -->
                <div class="pswp__preloader">
                    <div class="pswp__preloader__icn">
                      <div class="pswp__preloader__cut">
                        <div class="pswp__preloader__donut"></div>
                      </div>
                    </div>
                </div>
            </div>

            <div class="pswp__share-modal pswp__share-modal--hidden pswp__single-tap">
                <div class="pswp__share-tooltip"></div> 
            </div>

            <button class="pswp__button pswp__button--arrow--left" title="Previous (arrow left)">
            </button>

            <button class="pswp__button pswp__button--arrow--right" title="Next (arrow right)">
            </button>

            <div class="pswp__caption">
                <div class="pswp__caption__center"></div>
            </div>

          </div>

        </div>

</div>
<!-- end of Photoswipe HTML -->




<?php get_footer(); ?>

<!-- script to set up isotope and photoswipe and init  -->
this script courtesty of:
https://github.com/Iconoblast/radpress/blob/098a21be08bda5a42467556f9bb9cf9504d721d1/page-photoswipe-with-isotope.php

<script>
jQuery(document).ready(function($){
     //ISOTOPE AND PHOTOSWIPE
     var itemReveal = Isotope.Item.prototype.reveal;
        Isotope.Item.prototype.reveal = function() {
          itemReveal.apply( this, arguments );
          $( this.element ).removeClass('isotope-hidden');
        };
        var itemHide = Isotope.Item.prototype.hide;
        Isotope.Item.prototype.hide = function() {
          itemHide.apply( this, arguments );
          $( this.element ).addClass('isotope-hidden');
        };
        $('.isotope').isotope({
          itemSelector: '.image-item',

          masonry: {
            columnWidth: '.gallery-image'
            // isFitWidth: true
            // gutter: 10
          }, /* masonry */
          hiddenStyle: {
            opacity: 0
          },
          visibleStyle: {
            opacity: 1
          },
          transitionDuration: '0.5s',
        });
        // filter functions
        $('.navigate a').click(function(){
          var selector = $(this).attr('data-filter');
          // console.log('selector: '+ selector);
          $('.isotope').isotope({ filter: selector });
          return false;
           });
           $('.buttonlink').click(function(){
                 $('.buttonlink').removeClass('active');
                $(this).addClass('active');
         });
        /*
        Handle the dynamic image filtering.
        Instead of the `initPhotoSwipeFromDOM` code, you need to use
        */
        var initPhotoSwipeFromDOM = function(gallerySelector) {
          // parse slide data (url, title, size ...) from DOM elements 
          // (children of gallerySelector)
          var hash = '';
          var setHash = function setHash( newHash ){
            newHash = newHash || '';
            if(history.replaceState) {
                if (newHash[0] !== '#'){
                  newHash = '#' + newHash;
                }
                history.replaceState(null, null, newHash);
            }
            else {
              location.hash = newHash;
            }
          };
          var parseThumbnailElements = function(el) {
            var thumbElements = $(el).children(':not(.isotope-hidden)').get(),
                numNodes = thumbElements.length,
                items = [],
                figureEl,
                linkEl,
                size,
                item;
            for(var i = 0; i < numNodes; i++) {
              figureEl = thumbElements[i]; // <figure> element
              // include only element nodes 
              if(figureEl.nodeType !== 1) {
                continue;
              }
              linkEl = figureEl.children[0]; // <a> element
              size = linkEl.getAttribute('data-size').split('x');
              // create slide object
              item = {
                src: linkEl.getAttribute('href'),
                w: parseInt(size[0], 10),
                h: parseInt(size[1], 10)
              };
              if(figureEl.children.length > 1) {
                // <figcaption> content
                item.title = figureEl.children[1].innerHTML; 
              }
              if(linkEl.children.length > 0) {
                // <img> thumbnail element, retrieving thumbnail url
                item.msrc = linkEl.children[0].getAttribute('src');
              } 
              item.el = figureEl; // save link to element for getThumbBoundsFn
              items.push(item);
            }
            return items;
          };
          // find nearest parent element
          var closest = function closest(el, fn) {
            return el && ( fn(el) ? el : closest(el.parentNode, fn) );
          };
          // triggers when user clicks on thumbnail
          var onThumbnailsClick = function(e) {
            e = e || window.event;
            e.preventDefault ? e.preventDefault() : e.returnValue = false;
            var eTarget = e.target || e.srcElement;
            // find root element of slide
            var clickedListItem = closest(eTarget, function(el) {
              return (el.tagName && el.tagName.toUpperCase() === 'FIGURE');
            });
            if(!clickedListItem) {
              return;
            }
            // find index of clicked item by looping through all child nodes
            // alternatively, you may define index via data- attribute
            var clickedGallery = clickedListItem.parentNode,
                childNodes = $(clickedListItem.parentNode).children(':not(.isotope-hidden)').get(),
                numChildNodes = childNodes.length,
                nodeIndex = 0,
                index;
            for (var i = 0; i < numChildNodes; i++) {
              if(childNodes[i].nodeType !== 1) { 
                continue; 
              }
              if(childNodes[i] === clickedListItem) {
                index = nodeIndex;
                break;
              }
              nodeIndex++;
            }
            if(index >= 0) {
              // open PhotoSwipe if valid index found
              var id = eTarget.getAttribute('title');
              hash = window.location.hash;
              setHash( 'img=' + encodeURIComponent(id) );
              openPhotoSwipe( index, clickedGallery );
            }
            return false;
          };
          // parse custom imag eid #img=imagetitle
          var photoswipeParseHash = function() {
            var hash = window.location.hash.substring(1),
                params = {};
            if(hash.length < 5) {
              return params;
            }
            var pair = hash.split('=');
            if (pair.length === 2){
              params[pair[0]] = pair[1];
            }
            
            return params;
          };
          var openPhotoSwipe = function(index, galleryElement, disableAnimation) {
            var pswpElement = document.querySelectorAll('.pswp')[0],
                gallery,
                options,
                items;
            items = parseThumbnailElements(galleryElement);
            // define options (if needed)
            options = {
              index: index,
              history: false,
              // define gallery index (for URL)
              galleryUID: galleryElement.getAttribute('data-pswp-uid'),
              getThumbBoundsFn: function(index) {
                // See Options -> getThumbBoundsFn section of documentation for more info
                var thumbnail = items[index].el.getElementsByTagName('img')[0], // find thumbnail
                    pageYScroll = window.pageYOffset || document.documentElement.scrollTop,
                    rect = thumbnail.getBoundingClientRect(); 
                return {x:rect.left, y:rect.top + pageYScroll, w:rect.width};
              }
            };
            if(disableAnimation) {
              options.showAnimationDuration = 0;
            }
            // Pass data to PhotoSwipe and initialize it
            gallery = new PhotoSwipe( pswpElement, PhotoSwipeUI_Default, items, options);
            gallery.listen('destroy',function() { 
              setHash( hash );
            });
            gallery.listen('afterChange',function(){
              var id = $(this.items[ this.getCurrentIndex() ].el).find('a img').attr('title');
              setHash( 'img=' + encodeURIComponent(id) );
            });
            gallery.init();
          };
          // loop through all gallery elements and bind events
          var galleryElements = document.querySelectorAll( gallerySelector );
          for(var i = 0, l = galleryElements.length; i < l; i++) {
            galleryElements[i].setAttribute('data-pswp-uid', i+1);
            galleryElements[i].onclick = onThumbnailsClick;
          }
          // Parse URL and open gallery if it contains #&pid=3&gid=1
          var hashData = photoswipeParseHash();
          if(hashData.hasOwnProperty('img')) {
            var gallery = $(galleryElements[0]),
                figure = gallery.find('img[title="'+ hashData['img'] +'"]').closest('figure'),
                index = gallery.children('figure').index(figure);
                
            openPhotoSwipe( index,  galleryElements[0], true );
          }
        };
        // execute above function
        initPhotoSwipeFromDOM('.gallery_container');
        $('.isotope').imagesLoaded().progress( function() {
          console.log('imagesloaded');
          $('.isotope').isotope('layout');
        });
    
});
</script>