Rails模型中的实例变量 [英] Instance Variables in Rails Model

问题描述

我想在我的Rails模型中初始化一个实例变量，该实例变量将保存一个数组，并且我想在模型中的其他方法中访问此变量.我试过了:

I want to initialize an instance variable within my Rails model that will hold an array and I want to access this variable in other methods within my model. I tried this:

class Participant < ActiveRecord::Base

  @possible_statuses = [
    'exists',
    'paired',
    'quiz_finished',
    'quiz_results_seen',
    'money_sent'
  ]

  def statuses
    @possible_statuses
  end

但是当我尝试使用Rails控制台进行以下操作时:

But when I tried the following using rails console:

 Participant.first.statuses

我归零了:(

为什么会这样? 有什么方法可以完成我要完成的工作?

Why does this happen? Is there a way to accomplish what I am trying to accomplish?

推荐答案

对我来说，最好的答案是创建一个类变量，而不是实例变量:

The best answer for me was to create a class variable, not an instance variable:

@@possible_statuses = [
    'exists',
    'paired',
    'chat1_ready',
    'chat1_complete'
]

然后我可以在类的方法中自由访问它:

I could then freely access it in methods of the class:

  def status=(new_status)
    self.status_data = @@possible_statuses.index(new_status)
  end

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