refactor image headers

app/models/concerns/has_image_uploads.rb

@@ -9,11 +9,11 @@ module HasImageUploads
     # todo: destroy from s3 on destroy
 
     def public_image_uploads
-      self.image_uploads.where(privacy: 'public')
+      self.image_uploads.where(privacy: 'public').presence || ["card-headers/#{self.class.name.downcase.pluralize}.jpg"]
     end
 
     def private_image_uploads
-      self.image.uploads.where(privacy: 'private')
+      self.image.uploads.where(privacy: 'private').presence || ["card-headers/#{self.class.name.downcase.pluralize}.jpg"]
     end
 
     def random_image_including_private(format: :medium)

app/views/content/display/_image_card_header.html.erb

@@ -2,10 +2,7 @@
   <%= render partial: 'content/display/favorite_control', locals: { content: @content } %>
 
   <ul class="slides">
-    <% image_uploads = @content.image_uploads.map { |image| image.src.url(:large) } %>
-    <% image_uploads = ["card-headers/#{@content.class.name.downcase.pluralize}.jpg"] if image_uploads.empty? %>
-
-    <% image_uploads.each do |image_source| %>
+    <% @content.public_image_uploads.each do |image_source| %>
       <li>
         <%= image_tag image_source %>
         <div class="caption bordered-text center">

app/views/content/display/_sidelinks.html.erb

@@ -3,10 +3,6 @@
   editing  = defined?(editing)  && editing
 %>
 
-<%
-  raw_model = content.is_a?(ContentSerializer) ? content.raw_model : content
-%>
-
 <div>
   <%= render partial: 'content/display/sidebar/categories', locals: { content: content, creating: creating, editing: editing } %>
   <%= render partial: 'content/display/sidebar/references', locals: { content: content, creating: creating, editing: editing } %>