Code for creating a related articles widget using that uses labels to relate articles instead of whatever algorithm is used by default

article_template.html

  <aside class="article-sidebar side-column">
    {{recent_articles}}
    
    <!-- BEGIN CUSTOM SECTION FOR ARTICLES RELATED BY LABEL -->
    <section class="articles-related" id="label_related">
      <h3>Related articles</h3>
      <img id="label_rel_spinner" src="//p5.zdassets.com/hc/theme_assets/413487/200013043/loading.gif"/> <!-- You get this URL after uploading the loading.gif to assets -->
      <!-- source image uploaded to imgur here - http://i.imgur.com/JPrUDDz.gifv -->
    </section>
    <!-- END CUSTOM SECTION FOR ARTICLES RELATED BY LABEL -->
    
  </aside>

document_head_template.html

<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

javascript.js

// BEGIN RELATED ARTICLE CODE

// Get current article id
var path = window.location.pathname;
if (path.indexOf("articles") > -1) {
	var article_id = path.split('/')[4];
	
  function filter_results(data) {
  	var related_info = _.map(data, function(r){
   	 return {
     	 url: r.url,
     	 title: r.title
   	 }
 	 	});

    if (related_info.length > 0) {

      if (related_info.length > 3) related_info = related_info.slice(0,3);
      
  	var html = '<ul>';
  	_.each(related_info, function(obj){
    	html += "<li><a href='" + obj.url + "'>"+ obj.title + "</a></li>";
  	});
    html += '</ul>';

		$("img#label_rel_spinner").replaceWith(html); //change this to the related article box we will be creating
  }
  else {
    var html = "<p> There were no related articles</p>";
    $("img#label_rel_spinner").replaceWith(html);
  }
  };

	function query_labels(label_array) {  // Use current article labels to generate a new query for articles sharing labels
  	var labels_string = label_array.join(',');
  	$.ajax({
    	url: "/api/v2/help_center/articles/search.json?label_names=" + labels_string
  	}).done(function(response){
    	filter_results(response.results);
  	});
	};


	$.ajax({  // Use article id in request to retrieve current article labels
  	url: "/api/v2/help_center/articles/" + article_id + ".json"
	}).done(function(response){
  	var label_names = response.article.label_names;
  	query_labels(label_names);
	});
  
}

// END RELATED ARTICLE CODE