多态关联 - 控制器创建错误

Question

我做错了——我的应用程序中有多态关联，它运行良好——我可以通过 Rails 控制台将 cmets 添加到电影或导演中，没有问题。但是使用表单我得到错误“未初始化的常量 Comment::Commentable”。控制器和模型：

class CommentsController < ApplicationController
    before_action :find_comment, only: [:edit, :update, :destroy]
    before_action :logged_user

    def new
        if params[:movie_id]
            @movie = Movie.find(params[:movie_id])
        else
            @director = Director.find(params[:director_id])
        end
        @comment = Comment.new
    end

    def create
        if params[:movie_id]
            @commentable = Movie.find(params[:movie_id])
        else
            @commentable = Director.find(params[:director_id])
        end
        @comment = @commentable.comments.new(comment_params)
        @comment.user = current_user
        if @comment.save
            flash[:success] = 'Dodano komentarz.'
            redirect_to @commentable
        else
            flash[:danger] = 'Coś poszło nie tak, spróbuj ponownie.'
            render :new
        end
    end

    private
    def comment_params
        params.require(:comment).permit(:content, :grade)
    end

    def find_comment
        @comment = Comment.find(params[:id])
    end

end

class Movie < ActiveRecord::Base

    belongs_to :director
    has_many :comments, as: :commentable, dependent: :destroy
    has_many :users, through: :comments, source: :commentable, source_type: "User"
    accepts_nested_attributes_for :comments, :allow_destroy => true
end

class User < ActiveRecord::Base

    has_many :comments, dependent: :destroy
    has_many :movies, through: :comments, source: :commentable, source_type: "Movie"
    has_many :directors, through: :comments, source: :commentable, source_type: "Director"
    accepts_nested_attributes_for :comments, :allow_destroy => true
end

class Comment < ActiveRecord::Base
    belongs_to :commentable, polymorphic: true
    belongs_to :user

    validates_uniqueness_of :commentable, scope: :user
    validates :content, presence: true, length: { minimum: 40 }

end

我稍后会清理控制器，现在我只是想让它工作。请求中传入的参数：

{"utf8"=>"✓",
 "authenticity_token"=>"l+uouiN7H6hHArtiHGSw4MCsA8d37b60oDgNfskrTpwlDmJigLfBuMzYbA37mweInZEniVjzAzoPKB0dBRvJAA==",
 "comment"=>{"grade"=>"1",
 "content"=>"Lorem ipsum dolor sit amet enim. Etiam ullamcorper. Suspendisse a pellentesque dui,
 non felis. Maecenas malesuada elit lectus felis,
 malesuada ultricies. Curabitur et ligula. Ut molestie a,
 ultricies porta urna. Vestibulum commodo volutpat a,
 convallis ac,
 laoreet enim. Phasellus fermentum in,
 dolor. Pellentesque facilisis. Nulla imperdiet sit amet magna. Vestibulum dapibus,
 mauris nec malesuada fames ac turpis velit,
 rhoncus eu,
 luctus"},
 "commit"=>"Zapisz",
 "movie_id"=>"46"}

我不知道为什么，但是 user_id 没有在请求中传递。你能帮我么？我将不胜感激！

编辑： 意见表：

<%= render 'shared/errors', obj: @comment %>    
<div class="row">
    <div class="col-md-8 col-md-offset-2 well">
        <%= form_for @comment, url: new_or_edit do |f| %>

            <%= f.label 'Ocena' %>
            <%= f.select :grade, options_for_select(1..10) %>

            <%= f.label 'Komentarz' %>
            <%= f.text_area :content, rows: 5 %>

            <%= f.submit 'Zapisz', class: 'btn btn-success' %>
            <%= link_to 'Powrót', :back, class: 'btn btn-default uneditable-input' %>
        <% end %>
    </div>
</div>

架构：

  create_table "comments", force: :cascade do |t|
    t.string   "content"
    t.integer  "grade"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.integer  "commentable_id"
    t.string   "commentable_type"
    t.integer  "user_id"
  end

Answer 1

好的，它可以工作。问题是线

validates_uniqueness_of :commentable, scope: :user

改成之后就可以正常使用了：

validates :user, uniqueness: { scope: [ :commentable_type, :commentable_id ] }