Article layout YAML not read in head partial

#1

I get an undefined method `include?' for nil:NilClass error in my head.html.erb into my layout.erb as It isn’t seeing the YAML I have in my article.html.erb file. I’ve included it in a wrap as well both including the YAML and excluding it with no luck. This works fine for pages but not on articles. Is this due to the competing

    <!-- CSS -->
    <%= stylesheet_link_tag "/pages/post" if current_page.data.page_classes.include?("page_post") %>

    <!-- PAGE SPECIFIC CONTENT -->
    <%= yield_content :head %>
  </head>

  <body class="<%= current_page.data.page_classes %>">

article.html.erb

<% wrap_layout :layout do %>
---
page_classes: 'page_post'
page_title: 'News'
---

<div class="container news news-post">
  <div class="row">
    <div class="col-md-8 col-md-offset-2">
      <div class="user-story-header" style="margin-top: 50px;">
        <div class="user-story-title">
          <h1 class="title"><%= current_page.title %></h1>
        </div>
        <div class="case-share-buttons-container">
          <% partial '/partials/share-buttons' %>
        </div>
      </div>
    </div>
  </div><!-- /row -->
  <div class="row">
    <div class="col-md-8 col-md-offset-2">

      <div class="post">
          <div class="case-content">
            <%= yield %> <!--Articles content will render here -->
          </div>
      </div>

    </div>
  </div><!-- /row -->
</div><!-- /container -->
<% end %>

Example Article

contenttype: post
layout: case
title: "Article Title"
---

article text here