使用Angular post

Question

我正在尝试使用角度发送json到rails后端提交投票。我正试图将投票与用户联系起来。当我使用json＆amp;提交投票时angular，新的投票被添加到数据库，但user_id为null。我尝试使用仅使用rails进行提交并且它有效（投票有user_id）

控制器

def yesvote
    @question = Question.find(params[:id])
    yesvote = Yesvote.create(yes: params[:yes], user: current_user, question: @question)


    respond_to do |format|
        format.html{
            if yesvote.valid?
                redirect_to :back
            else 
                flash[:danger] = "once only!"
                redirect_to :back
            end
        }
        format.json{
            if yesvote.save
                render status: 200, json: yesvote
            else
                render status: 422, json: {
                message: "failed.",
                errors: yesvote.errors
                }.to_json
            end
        }
    end
end

角

$scope.voteYes = function (){
   var parameter = JSON.stringify({ yes: true });
   $http.post('/questions/' + $scope.number + '/yesvote.json', parameter)
      .success(function (result) {
            console.log(result);
      })
      .error(function (data, status) {
            console.log(data);
      });
}

yesvote model

class Yesvote < ActiveRecord::Base
    belongs_to :user
    belongs_to :question
    validates_uniqueness_of :user, :allow_blank => true, scope: :question
end

sessions_helper current_user

def current_user
    if (user_id = session[:user_id])
        @current_user ||= User.find_by(id: user_id)
    elsif (user_id = cookies.signed[:user_id])
        user = User.find_by(id: user_id)
        if user && user.authenticated?(cookies[:remember_token])
            log_in user
            @current_user = user
        end
    end
end