Add ability to use nested only parameter

- The only string works much the same as before with its comma separation
-- Nested includes are indicated with square brackets "[ ]"
-- The nested include is the value immediately preceding the square brackets
-- The only string is the comma separated string inside those brackets
- Default includes are split between format types when necessary
-- This prevents unnecessary includes from being added on page load
- Available includes are those items which are allowed to be accessible to the user
-- Some aren't because they are sensitive, such as the creator of a flag
-- Some aren't because the number of associated items is too large
- The amount of times the same model can be included to prevent recursions
-- One exception is the root model may include the same model once
--- e.g. the user model can include the inviter which is also the user model
-- Another exception is if the include is a has_many association
--- e.g. artist urls can include the artist, and then artist urls again

app/controllers/pool_versions_controller.rb

@@ -8,7 +8,7 @@ class PoolVersionsController < ApplicationController
       @pool = Pool.find(params[:search][:pool_id])
     end
 
-    @pool_versions = PoolArchive.paginated_search(params).includes(:updater, :pool)
+    @pool_versions = PoolArchive.paginated_search(params).includes(model_includes(params))
     respond_with(@pool_versions)
   end
 
@@ -27,6 +27,18 @@ class PoolVersionsController < ApplicationController
 
   private
 
+  def model_name
+    "PoolArchive"
+  end
+
+  def default_includes(params)
+    if ["json", "xml"].include?(params[:format])
+      []
+    else
+      [:updater, :pool]
+    end
+  end
+
   def set_timeout
     PoolArchive.connection.execute("SET statement_timeout = #{CurrentUser.user.statement_timeout}")
     yield