導軌上出現nil：NilClass錯誤的未定義方法“鍵”

Question

我試圖運行Web服務器，它顯示以下錯誤：

導軌上出現nil：NilClass錯誤的未定義方法“鍵”

提取的源（圍繞第21行）：

     shopsList = [st1, st2, st3, st4]

     render :json => shopsList
   end
end

這些是文件：

shop.rb

class Shop < ActiveRecord::Base
  attr_accessor :name, :description, :comments

  def initialize(name, description, comments)
    @name = name
    @description = description
    @comments = []
  end
end

comment.rb

class Comment
  attr_accessor :id, :name, :content

  def initialize(id, name, content)
    @id = id
    @name = name
    @content = content
  end
end

shop_controller.rb

class ShopsController < ApplicationController
  def index
  end

  def shops
    com1 = Comment.new("FX991", "Goat", "Delicious!")
    com2 = Comment.new("F2888", "Cow", "Amazing!")
    com3 = Comment.new("GH555", "Cat", "Yummm!")
    com4 = Comment.new("HY666", "Fish", "Mouth watering!")
    commentList = [com1, com2, com3, com4]

    sh1 = Shop.new("AAAA", "Je", commentList[0])
    sh2 = Shop.new("NNNN", "Te", commentList[1])
    sh3 = Shop.new("CCCC", "Be", commentList[1])
    sh4 = Shop.new("DDDD", "He", commentList[1])
    shopsList = [sh1, sh2, sh3, sh4]

    render :json => shopsList
  end
end

當我嘗試將render :json => shopsList為render :json => commentList ，注釋列表在服務器中將顯示為json格式。

另外，我訪問或聲明commentList數組的方式是否有問題？ 當我嘗試訪問該數組時，不會顯示該數組的內容。 它只顯示“ []”

Answer 1

您需要傳遞一個哈希值以進行render

嘗試這個

shopsList = [sh1, sh2, sh3, sh4]

render :json => {:success=>true, :data=>shopsList}

Answer 2

你能發布stacktrace嗎？

我不認為“渲染”會導致錯誤，我認為它發生在調用堆棧的前面。

#tested this, it is valid code
def mytest
  data = ["1","2","3"]
  render :json => data
end