rails将参数传递给'new'方法

Question

显然我对铁轨很新,所以坚持下去.

我在我的模型中添加了一个构造函数

class Movie < Media
  attr_accessible :director, :studio
  attr_accessor :director, :studio

  validates_presence_of :director, :studio, :title
  def initialize title, director, studio
    @title = title
    @director = director
    @studio = studio
  end
end

那种搞砸了我的东西.因为我在我的控制器中有一个方法'new'就像这样

def new
    @movies = Movie.new
end

并且在初始化出现之前它工作得很好.它需要将参数传递给'new'方法,但这是在视图打开后从用户传递参数并保存它们时完成的.现在我无法打开该视图,因为我收到错误

wrong number of arguments (0 for 3)

添加构造函数是因为我开始为我的应用程序编写测试,并且为构造函数设置默认值会使该测试无效.解决这个问题的建议？

编辑:我的测试看起来像这样:

require 'spec_helper'

describe Movie do

    before :each do 
        @movie = Movie.new "Bullet", "John", "20th"
    end
    describe "#{new}" do
        it "returns new object of Movie" do
            @movie.should be_an_instance_of Movie
        end
        it "throws ArgumentError when give less than 3 parameters" do
            lambda {Movie.new(:director => "John", :studio => "20th")}.should raise_exception ArgumentError
        end
    end

    describe "#title" do
        it "returns the correct title" do
            @movie.title.should eql "Bullet"
        end
    end
    describe "#director" do
        it "returns the correct director" do
            @movie.director.should eql "John"
        end
    end
    describe "#studio" do
        it "returns the correct studio" do
            @movie.studio.should eql "20th"
        end
    end
end

没有那个构造函数,所有测试都失败了......

Answer 1

ActiveModel提供的默认构造函数非常好.如果删除了你编写的构造函数,你应该能够使用如下的默认构造函数:

@movie = Movie.new(title: 'The Hobbit', director: 'Peter Jackson', studio: 'New Line Cinema')

当你不想提供三个参数时(比如你的new行动),你可以坚持下去@movie = Movie.new