* Approvers can no longer approve an unapproved post if they previously approved it

app/logical/current_user.rb

@@ -34,6 +34,10 @@ class CurrentUser
     user.id
   end
   
+  def self.name
+    user.name
+  end
+  
   def self.method_missing(method, *params, &block)
     if user.respond_to?(method)
       user.__send__(method, *params, &block)

app/models/post.rb

@@ -1,4 +1,6 @@
 class Post < ActiveRecord::Base
+  class ApprovalError < Exception ; end
+  
   attr_accessor :old_tag_string, :old_parent_id
   after_destroy :delete_files
   after_save :update_history
@@ -211,9 +213,11 @@ class Post < ActiveRecord::Base
     end
 
     def approve!
+      raise ApprovalError.new("You have already approved this post previously") if approver_string == "approver:#{CurrentUser.name}"
+      
       self.is_flagged = false
       self.is_pending = false
-      self.approver_string = "approver:#{CurrentUser.user.name}"
+      self.approver_string = "approver:#{CurrentUser.name}"
       save!
     end
   end