REFACTOR: Merge different templates from rendering user stream items

app/serializers/admin_user_action_serializer.rb

@@ -0,0 +1,84 @@
+class AdminUserActionSerializer < ApplicationSerializer
+
+  attributes(
+    :id,
+    :created_at,
+    :post_number,
+    :name,
+    :username,
+    :avatar_template,
+    :topic_id,
+    :slug,
+    :title,
+    :category_id,
+    :excerpt,
+    :hidden,
+    :moderator_action,
+    :deleted,
+    :deleted_at,
+    :deleted_by,
+    :reply_to_post_number,
+    :action_type
+  )
+
+  def deleted
+    deleted_at.present?
+  end
+
+  def name
+    object.user.name
+  end
+
+  def include_name?
+    SiteSetting.enable_names?
+  end
+
+  def username
+    object.user.username
+  end
+
+  def avatar_template
+    object.user.avatar_template
+  end
+
+  def slug
+    topic.slug
+  end
+
+  def title
+    topic.title
+  end
+
+  def category_id
+    topic.category_id
+  end
+
+  def moderator_action
+    object.post_type == Post.types[:moderator_action] || object.post_type == Post.types[:small_action]
+  end
+
+  def deleted_by
+    BasicUserSerializer.new(object.deleted_by, root: false).as_json
+  end
+
+  def include_deleted_by?
+    object.trashed?
+  end
+
+  def action_type
+    object.user_actions.select { |ua| ua.user_id = object.user_id }
+                       .select { |ua| [UserAction::REPLY, UserAction::RESPONSE].include? ua.action_type }
+                       .first.try(:action_type)
+  end
+
+  private
+
+    # we need this to handle deleted topics which aren't loaded via the .includes(:topic)
+    # because Rails 4 "unscoped" support is bugged (cf. https://github.com/rails/rails/issues/13775)
+    def topic
+      return @topic if @topic
+      @topic = object.topic || Topic.with_deleted.find(object.topic_id)
+      @topic
+    end
+
+end