gistfile1.rb

def create
  attrs     = params[:group_question]
  group_id  = params[:group_id]
  if @group    = Group.find group_id
    @question = _user.group_question group, attrs
    @result   = @question.errors.messages.map{|k,v| "#{v[0]}<br/>" } unless @question.save
  end
  json_only_action
end

# This should be an after_create callback for question
_user.deliver_group_question @question if @question.group.instructor_id