def validate_parent_id
   return true if User.current.admin?
   parent_id = params[:project] && params[:project][:parent_id]
   if parent_id || @project.new_record?
     parent = parent_id.blank? ? nil : Project.find_by_id(parent_id.to_i)
     unless @project.allowed_parents.include?(parent)
       @project.errors.add :parent_id, :invalid
       return false
     end
   end
   true
 end