Lower the number of returned unread notifications

After talking to the mobile team we cam to the conclusion that for the API and the mobile apps speed is of the utmost importance when working with notifications. So we agreed to lower the unread notifications limit to 100 like we have in Basecamp. This strikes a balance between speed and usability.

app/controllers/notifications_controller.rb

@@ -1,8 +1,9 @@
 class NotificationsController < ApplicationController
   MAX_UNREAD_NOTIFICATIONS = 500
+  MAX_UNREAD_NOTIFICATIONS_VIA_API = 100
 
   def index
-    @unread = Current.user.notifications.unread.ordered.preloaded.limit(MAX_UNREAD_NOTIFICATIONS) unless current_page_param
+    @unread = Current.user.notifications.unread.ordered.preloaded.limit(max_unread_notifications) unless current_page_param
     set_page_and_extract_portion_from Current.user.notifications.read.ordered.preloaded
 
     respond_to do |format|
@@ -11,4 +12,9 @@ class NotificationsController < ApplicationController
       format.json
     end
   end
+
+  private
+    def max_unread_notifications
+      request.format.json? ? MAX_UNREAD_NOTIFICATIONS_VIA_API : MAX_UNREAD_NOTIFICATIONS
+    end
 end