Question

我正在研究一个项目，对于我的生活，我不确定发生了什么。我的代码工作得比较早，现在我正在

NoMethodError in MoviesController#upvote

当我尝试对某部电影投票时，这是我的“movie_controller.rb”

class MoviesController < ApplicationController
  before_action :set_movie, only: [:show, :edit, :update, :destroy, :upvote, :downvote]
  before_action :authenticate_user! 


  # GET /movies
  # GET /movies.json
  def index
    @movies = Movie.all
  end

  # GET /movies/1
  # GET /movies/1.json
  def show
  end

  # GET /movies/new
  def new
    @movie = Movie.new
  end

  # GET /movies/1/edit
  def edit
  end

  # POST /movies
  # POST /movies.json
  def create
    @movie = Movie.new(movie_params)

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

  # PATCH/PUT /movies/1
  # PATCH/PUT /movies/1.json
  def update
    respond_to do |format|
      if @movie.update(movie_params)
        format.html { redirect_to @movie, notice: 'Movie was successfully updated.' }
        format.json { render :show, status: :ok, location: @movie }
      else
        format.html { render :edit }
        format.json { render json: @movie.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /movies/1
  # DELETE /movies/1.json
  def destroy
    @movie.destroy
    respond_to do |format|
      format.html { redirect_to movies_url, notice: 'Movie was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  def upvote
    @movie.upvote_from current_user 
    redirect_to movies_path
  end

  def downvote
    @movie.downvote_from current_user
    redirect_to movies_path
  end

  private
    def set_movie 
      @movies = Movie.find(params[:movie_id])
    end 


    # Never trust parameters from the scary internet, only allow the white list through.
    def movie_params
      params.require(:movie).permit(:title, :image)
    end
end

特别是它说是行有问题：

private
    def set_movie 
      @movies = Movie.find(params[:id])
    end

我还会附上好路线。谢谢你们。

Rails.application.routes.draw do
    devise_for :users
    root 'home#index'

    resources :movies do

    put "like", to: "movies#upvote"
    put "unlike", to: "movies#downvote"
  end
end

Answer 1

问题是您要设置@movies变量而不是@movie。这就是你获得undefined method upvote_from' for nil:NilClass def upvote @movie.upvote_from

的原因

更改代码的这一部分

private
def set_movie 
  @movies = Movie.find(params[:id])
end

到这个

private
def set_movie 
  @movie = Movie.find(params[:id])
end

MoviesController＃upvote中的NoMethodError

1 个答案: