Question

帮我StackOveflow，你是我唯一的希望。

我收到了以下错误，它让我发疯了。

玩家中的NoMethodError＃new

显示/home/paul/rails_projects/recruits/app/views/players/_form.html.haml，其中第1行被提出：

未定义的方法`model_name'为nil：NilClass

提取的来源（第1行）：

1：= form_for @player do | f |

2：-if @ player.errors.any？

3：#error_explanation

4：％h2 =“＃{pluralize（@ player.errors.count，”error“）}禁止此播放器被保存：”

模板包含跟踪：app / views / players / new.html.haml

Rails.root：/ home / paul / rails_projects / recruits    应用程序跟踪|框架跟踪|完整跟踪

app / views / players / _form.html.haml：1：in _app_views_players__form_html_haml___279577567_106102840' app/views/players/new.html.haml:3:in _ app_views_players_new_html_haml__860668925_106567710'    app / controllers / players_controller.rb：29：在'new'

我使用脚手架发生器创建了这个，它在另一个区域对我很好，但显然不在这里。

以下是相关文件（我对scaffold命令生成的文件所做的唯一更改是将attr_accessable添加到播放器模型中）。

模型/ player.rb

class Player < ActiveRecord::Base 

  attr_accessible :first_name, :last_name, :scout_height, :scout_weight,
  :scout_profile_url, :scout_star_rating, :scout_overall_ranking,
  :scout_position_ranking, :scout_position, :espn_height, :espn_weight,
  :espn_profile_url, :espn_star_rating, :espn_overall_ranking,
  :espn_position_ranking, :espn_position, :rivals_height, :rivals_weight,
  :rivals_profile_url, :rivals_star_rating, :rivals_overall_ranking,
  :rivals_position_ranking, :rivals_position, :maxprep_height, :maxprep_weight,
  :maxprep_profile_url, :maxprep_star_rating, :maxprep_overall_ranking,
  :maxprep_position_ranking, :maxprep_position, :class, :school_commit, :loi_signed

end

控制器/ players_controller.rb

class PlayersController < ApplicationController
  # GET /players
  # GET /players.json
  def index
    @players = Player.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @players }
    end
  end

  # GET /players/1
  # GET /players/1.json
  def show
    @player = Player.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @player }
    end
  end

  # GET /players/new
  # GET /players/new.json
  def new
    @player = Player.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @player }
    end
  end

  # GET /players/1/edit
  def edit
    @player = Player.find(params[:id])
  end

  # POST /players
  # POST /players.json
  def create
    @player = Player.new(params[:player])

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

  # PUT /players/1
  # PUT /players/1.json
  def update
    @player = Player.find(params[:id])

    respond_to do |format|
      if @player.update_attributes(params[:player])
        format.html { redirect_to @player, notice: 'Player was successfully updated.' }
        format.json { head :ok }
      else
        format.html { render action: "edit" }
        format.json { render json: @player.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /players/1
  # DELETE /players/1.json
  def destroy
    @player = Player.find(params[:id])
    @player.destroy

    respond_to do |format|
      format.html { redirect_to players_url }
      format.json { head :ok }
    end
  end
end

视图/播放器/ new.html.haml

%h1 New player

= render 'form'

= link_to 'Back', players_path

视图/播放器/ _form.html.haml

= form_for @player do |f|
  -if @player.errors.any?
    #error_explanation
      %h2= "#{pluralize(@player.errors.count, "error")} prohibited this player from being saved:"
      %ul
        - @player.errors.full_messages.each do |msg|
          %li= msg

  .field
    = f.label :first_name
    = f.text_field :first_name
  .field
    = f.label :last_name
    = f.text_field :last_name
  .field
    = f.label :scout_height
    = f.number_field :scout_height
  .field
    = f.label :scout_weight
    = f.number_field :scout_weight
  .field
    = f.label :scout_profile_url
    = f.text_field :scout_profile_url
  .field
    = f.label :scout_star_rating
    = f.number_field :scout_star_rating
  .field
    = f.label :scout_overall_ranking
    = f.number_field :scout_overall_ranking
  .field
    = f.label :scout_position_ranking
    = f.number_field :scout_position_ranking
  .field
    = f.label :scout_position
    = f.text_field :scout_position
  .field
    = f.label :espn_height
    = f.number_field :espn_height
  .field
    = f.label :espn_weight
    = f.number_field :espn_weight
  .field
    = f.label :espn_profile_url
    = f.text_field :espn_profile_url
  .field
    = f.label :espn_star_rating
    = f.number_field :espn_star_rating
  .field
    = f.label :espn_overall_ranking
    = f.number_field :espn_overall_ranking
  .field
    = f.label :espn_position_ranking
    = f.number_field :espn_position_ranking
  .field
    = f.label :espn_position
    = f.text_field :espn_position
  .field
    = f.label :rivals_height
    = f.number_field :rivals_height
  .field
    = f.label :rivals_weight
    = f.number_field :rivals_weight
  .field
    = f.label :rivals_profile_url
    = f.text_field :rivals_profile_url
  .field
    = f.label :rivals_star_rating
    = f.number_field :rivals_star_rating
  .field
    = f.label :rivals_overall_ranking
    = f.number_field :rivals_overall_ranking
  .field
    = f.label :rivals_position_ranking
    = f.number_field :rivals_position_ranking
  .field
    = f.label :rivals_position
    = f.text_field :rivals_position
  .field
    = f.label :maxprep_height
    = f.number_field :maxprep_height
  .field
    = f.label :maxprep_weight
    = f.number_field :maxprep_weight
  .field
    = f.label :maxprep_profile_url
    = f.text_field :maxprep_profile_url
  .field
    = f.label :maxprep_star_rating
    = f.number_field :maxprep_star_rating
  .field
    = f.label :maxprep_overall_ranking
    = f.number_field :maxprep_overall_ranking
  .field
    = f.label :maxprep_position_ranking
    = f.number_field :maxprep_position_ranking
  .field
    = f.label :maxprep_position
    = f.text_field :maxprep_position
  .field
    = f.label :class
    = f.number_field :class
  .field
    = f.label :school_commit
    = f.text_field :school_commit
  .field
    = f.label :loi_signed
    = f.check_box :loi_signed
  .actions
    = f.submit 'Save'

的routes.rb

Recruits::Application.routes.draw do

  resources :schools
  resources :players

  #get \"users\/show\"

  root :to => "home#index"

  devise_for :users
  resources :users, :only => :show
end

Answer 1

我在这里猜测，但我相信这是因为你给了你的玩家模型一个叫做“类”的属性，你应该将其改为：player_class或者什么。 class是保留字。您还应该更新_form.html.erb和index.html.erb以及show.html.erb文件以使用此新名称。

Rails 3.1 Scaffold undefined方法`model_name'代表nil：NilClass

1 个答案: