如何允许具有强参数的数组

Question

我有一个功能正常的Rails 3应用程序使用has_many:通过关联,当我将其重新设置为Rails 4应用程序时,让我从Rails 4版本中的相关模型中保存ID.

这两个版本的三个相关模型是相同的.

Categorization.rb

class Categorization < ActiveRecord::Base

  belongs_to :question
  belongs_to :category
end

Question.rb

has_many :categorizations
has_many :categories, through: :categorizations

Category.rb

has_many :categorizations
has_many :questions, through: :categorizations

在这两个应用程序中,类别ID都会像这样传递到create动作中

  "question"=>{"question_content"=>"How do you spell car?", "question_details"=>"blah ", "category_ids"=>["", "2"],

在Rails 3应用程序中,当我创建一个新问题时,它会插入问题表,然后插入到分类表中

 SQL (82.1ms)  INSERT INTO "questions" ("accepted_answer_id", "city", "created_at", "details", "province", "province_id", "question", "updated_at", "user_id") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)  [["accepted_answer_id", nil], ["city", "dd"], ["created_at", Tue, 14 May 2013 17:10:25 UTC +00:00], ["details", "greyound?"], ["province", nil], ["province_id", 2], ["question", "Whos' the biggest dog in the world"], ["updated_at", Tue, 14 May 2013 17:10:25 UTC +00:00], ["user_id", 53]]
  SQL (0.4ms)  INSERT INTO "categorizations" ("category_id", "created_at", "question_id", "updated_at") VALUES (?, ?, ?, ?)  [["category_id", 2], ["created_at", Tue, 14 May 2013 17:10:25 UTC +00:00], ["question_id", 66], ["updated_at", Tue, 14 May 2013 17:10:25 UTC +00:00]]

在rails 4应用程序中,在处理QuestionController #create中的参数之后,我在服务器日志中收到此错误

Unpermitted parameters: category_ids

问题只是插入到问题表中

 (0.2ms)  BEGIN
  SQL (67.6ms)  INSERT INTO "questions" ("city", "created_at", "province_id", "question_content", "question_details", "updated_at", "user_id") VALUES ($1, $2, $3, $4, $5, $6, $7) RETURNING "id"  [["city", "dd"], ["created_at", Tue, 14 May 2013 17:17:53 UTC +00:00], ["province_id", 3], ["question_content", "How's your car?"], ["question_details", "is it runnign"], ["updated_at", Tue, 14 May 2013 17:17:53 UTC +00:00], ["user_id", 12]]
   (31.9ms)  COMMIT

虽然我没有在Questions模型中存储category_ids,但我将categories_ids设置为questions_controller中的允许参数

   def question_params

      params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids)
    end

任何人都可以解释我应该如何保存category_ids？请注意,任一应用程序的categories_controller.rb中都没有创建操作.

这两个应用程序中的三个表是相同的

 create_table "questions", force: true do |t|
    t.text     "question_details"
    t.string   "question_content"
    t.integer  "user_id"
    t.integer  "accepted_answer_id"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.integer  "province_id"
    t.string   "city"
  end

 create_table "categories", force: true do |t|
    t.string   "name"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "categorizations", force: true do |t|
    t.integer  "category_id"
    t.integer  "question_id"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

更新

这是Rails 3应用程序的创建操作

  def create
      @question = Question.new(params[:question])
      respond_to do |format|
      if @question.save
        format.html { redirect_to @question, notice: 'Question was successfully created.' }
        format.json { render json: @question, status: :created, location: @question }
      else
        format.html { render action: "new" }
        format.json { render json: @question.errors, status: :unprocessable_entity }
      end
    end
end

这是Rails 4应用程序的创建操作

   def create
      @question = Question.new(question_params)

       respond_to do |format|
      if @question.save
        format.html { redirect_to @question, notice: 'Question was successfully created.' }
        format.json { render json: @question, status: :created, location: @question }
      else
        format.html { render action: "new" }
        format.json { render json: @question.errors, status: :unprocessable_entity }
      end
    end
    end

这是question_params方法

 private
    def question_params 
      params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids)
    end

Answer 1

这个https://github.com/rails/strong_parameters看起来像文档的相关部分:

允许的标量类型是String,Symbol,NilClass,Numeric,TrueClass,FalseClass,Date,Time,DateTime,StringIO,IO,ActionDispatch :: Http :: UploadedFile和Rack :: Test :: UploadedFile.

要声明params中的值必须是允许的标量值数组,请将键映射到空数组:

params.permit(:id => [])

在我的应用程序中,category_ids被传递给数组中的create动作

"category_ids"=>["", "2"],

因此,在声明强参数时,我明确将category_ids设置为数组

params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids => [])

现在完美运作!

Answer 2

如果要允许哈希数组(或an array of objects从JSON的角度来看)

params.permit(:foo, array: [:key1, :key2])

2点注意到这里:

1. array应该是该permit方法的最后一个参数.
2. 你应该在数组中指定哈希的键,否则你会得到一个错误Unpermitted parameter: array,在这种情况下很难调试.

Answer 3

应该是这样的

params.permit(:id => [])

也可以使用rails 4+以上版本:

params.permit(id: [])

Answer 4

如果你有这样的哈希结构:

Parameters: {"link"=>{"title"=>"Something", "time_span"=>[{"start"=>"2017-05-06T16:00:00.000Z", "end"=>"2017-05-06T17:00:00.000Z"}]}}

然后我就是这样做的:

params.require(:link).permit(:title, time_span: [[:start, :end]])

Answer 5

当你想允许多个数组字段时，你必须在允许的情况下最后列出数组字段，如给定 -

params.require(:questions).permit(:question, :user_id, answers: [], selected_answer: [] )

（这有效）

Answer 6

我还不能发表评论，但是在Fellow Stranger解决方案之后，您还可以保留嵌套，以防您拥有键值是数组的情况。像这样：

filters: [{ name: 'test name', values: ['test value 1', 'test value 2'] }]

这有效：

params.require(:model).permit(filters: [[:name, values: []]])