Rails DateTime-NoMethodError（nil：NilClass的未定义方法“ []”）

Question

这是我的模型：

class User < ActiveRecord::Base
has_many :appointments
has_many :doctors, :through => :appointments
end

class Doctor < ActiveRecord::Base
has_many :appointments
has_many :users, :through => :appointments
end

class Appointment < ActiveRecord::Base
belongs_to :doctor
belongs_to :user
end

调用控制器动作的代码：

$.ajax({
  type: "POST",
  url: "/create",
  data: {
    appointment_date: date,
    doctor_id: "1",
    user_id: "1"
  }

//等}）;

行动：

def create
    @appointment = Appointment.new(:appointment_date => params[:data][:appointment_date], 
        :hairdresser_id => params[:data][:doctor_id], :user_id => params[:data][:user_id])
    if @appointment.save
        flash[:success] = "Welcome!"
        redirect_to @user
    else
        alert("failure!")
    end
end

我得到了这个错误：

NoMethodError (undefined method `[]' for nil:NilClass)

我正在使用FullCalendar插件，它以这种格式获取日期：

Fri Sep 13 2013 12:00:50 GMT-0400 (EDT)

我将该日期保存到datetime字段中的数据库中。

有任何想法吗？

Answer 1

进行ajax调用时，可以访问诸如

params[:appointment_date]
params[:doctor_id]
params[:user_id]

并不是

params[:data][:appointment_date]
params[:data][:doctor_id]
params[:data][:user_id]

由于没有什么叫做params [：data]的东西，所以给你一个nil类错误。

Answer 2

如果它是约会控制器的create action，那么它将是

$.ajax({
  type: "POST",
  url: "/appointments",
  data: {
    appointment_date: date,
    doctor_id: "1",
    user_id: "1"
  }

在创建动作中

def create
    @appointment = Appointment.new({:appointment_date => params['appointment_date'], 
        :hairdresser_id => params['doctor_id'], :user_id => params['user_id]'})
    if @appointment.save
        #YOUR CODE
    else
        #YOUR CODE
    end
end