app/views/tag/index.html.erb
<h3>Posts tagged as <%= @tag.tag_name %> <a class="fa fa-rss" href="/feed/tag/<%= @tag.tag_slug %>.xml"></a></h3>
<hr />
<% if @posts != nil %>
<% @posts.each do |p| %>
<%= render 'post', {p: p} %>
<% end %>
<% else %>
<div class="alert alert-danger">
<strong>Error!</strong><br />
There are currently no posts available.
</div>
<% end %>