Add "group by array" include to simplify archive pages

_pages/tag-archive.html

@@ -4,23 +4,19 @@ permalink: /tag-archive/
 title: "Posts by Tags"
 ---
 {% include absolute-url.liquid %}
-{% capture site_tags %}{% for tag in site.tags %}{{ tag | first }}{% unless forloop.last %},{% endunless %}{% endfor %}{% endcapture %}
-{% assign tag_list = site_tags | split:',' | sort %}
+{% include group-by-array.html collection=site.posts field='tags' %}
 
-{% for item in (0..site.tags.size) %}
-  {% unless forloop.last %}
-    {% capture tag_name %}{{ tag_list[item] | strip_newlines }}{% endcapture %}
-      <h3>{{ tag_name }}</h3>
-      {% for post in site.tags[tag_name] %}{% if post.title != null %}
-        <article itemscope itemtype="http://schema.org/CreativeWork">
-          {% if post.link %}
-            <h2 class="link-post" itemprop="headline"><a href="{{ absurl }}{{ post.url }}" title="{{ post.title }}">{{ post.title }}</a> <a href="{{ post.link }}" target="_blank" title="{{ post.title }}"><i class="fa fa-link"></i></a></h2>
-          {% else %}
-            <h2 itemprop="headline"><a href="{{ absurl }}{{ post.url }}" title="{{ post.title }}">{{ post.title }}</a></h2>
-            <p itemprop="description">{{ post.excerpt | markdownify | strip_html | strip_newlines | escape_once }}</p>
-          {% endif %}
-        </article>
-        {% endif %}
-      {% endfor %}
-  {% endunless %}
+{% for tag in group_names %}
+  {% assign posts = group_items[forloop.index0] %}
+  <h3>{{ tag }}</h3>
+  {% for post in posts %}
+    <article itemscope itemtype="http://schema.org/CreativeWork">
+      {% if post.link %}
+        <h2 class="link-post" itemprop="headline"><a href="{{ absurl }}{{ post.url }}" title="{{ post.title }}">{{ post.title }}</a> <a href="{{ post.link }}" target="_blank" title="{{ post.title }}"><i class="fa fa-link"></i></a></h2>
+      {% else %}
+        <h2 itemprop="headline"><a href="{{ absurl }}{{ post.url }}" title="{{ post.title }}">{{ post.title }}</a></h2>
+        <p itemprop="description">{{ post.excerpt | markdownify | strip_html | strip_newlines | escape_once }}</p>
+      {% endif %}
+    </article>
+  {% endfor %}
 {% endfor %}