1

これに関するヘルプを求めて SO に関する多くの Q&A を読みましたが、これまでのところ私の問題は解決していません。私はルビー/レールを独学しようとしています.テストプロジェクトとして、テレビ番組のリストと、各テレビ番組が_多くの文字を持ち、各文字が特定の番組に属している文字のリストを作成したいと考えています. 基本的なことを間違っていると確信しています。どんな援助でも大歓迎です。

ここにキャラクターコントローラーがあります：

    class CharactersController < ApplicationController
  before_action :set_character, only: [:show, :edit, :update, :destroy]

  # GET /characters
  # GET /characters.json
  def index
    @characters = Character.all
  end

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

  # GET /characters/new
  def new
    @character = Character.new
  end

  # GET /characters/1/edit
  def edit
  end

  # POST /characters
  # POST /characters.json
  def create
    @character = @tvshow.characters.create(params[:character])

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

  # PATCH/PUT /characters/1
  # PATCH/PUT /characters/1.json
  def update
    respond_to do |format|
      if @character.update(character_params)
        format.html { redirect_to @character, notice: 'Character was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @character.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /characters/1
  # DELETE /characters/1.json
  def destroy
    @character.destroy
    respond_to do |format|
      format.html { redirect_to characters_url }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_character
      @character = Character.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def character_params
      params.require(:character).permit(:first_name, :last_name, :bio)
    end
end

キャラクターモデル:

class Character < ActiveRecord::Base
belongs_to :tvshow
default_scope -> { order('created_at DESC') }
validates :tvshow_id, presence: true
end

テレビ番組モデル:

class Tvshow < ActiveRecord::Base
has_many :characters, dependent: :destroy
end

キャラクターを作成しようとするとエラーが返されます。完全なトレースは次のとおりです。

app/controllers/characters_controller.rb:27:in `create'
actionpack (4.0.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.0.0) lib/abstract_controller/base.rb:189:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.0.0) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (4.0.0) lib/active_support/callbacks.rb:413:in     `_run__1211653665462320621__process_action__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.0.0) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.0.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.0.0) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
activerecord (4.0.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.0.0) lib/abstract_controller/base.rb:136:in `process'
actionpack (4.0.0) lib/abstract_controller/rendering.rb:44:in `process'
actionpack (4.0.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.0.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.0.0) lib/action_controller/metal.rb:231:in `block in action'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:48:in `call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:71:in `block in call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:655:in `call'
rack (1.5.2) lib/rack/etag.rb:23:in `call'
rack (1.5.2) lib/rack/conditionalget.rb:35:in `call'
rack (1.5.2) lib/rack/head.rb:11:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/flash.rb:241:in `call'
rack (1.5.2) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.5.2) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/cookies.rb:486:in `call'
activerecord (4.0.0) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
activerecord (4.0.0) lib/active_record/migration.rb:369:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.0.0) lib/active_support/callbacks.rb:373:in     `_run__2792846465963916895__call__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/reloader.rb:64:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.0.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.0.0) lib/rails/rack/logger.rb:21:in `block in call'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `block in tagged'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:25:in `tagged'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `tagged'
railties (4.0.0) lib/rails/rack/logger.rb:21:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.5.2) lib/rack/methodoverride.rb:21:in `call'
rack (1.5.2) lib/rack/runtime.rb:17:in `call'
activesupport (4.0.0) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/static.rb:64:in `call'
railties (4.0.0) lib/rails/engine.rb:511:in `call'
railties (4.0.0) lib/rails/application.rb:97:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
rack (1.5.2) lib/rack/content_length.rb:14:in `call'
rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
/Users/dariusgoore/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'
/Users/dariusgoore/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'
/Users/dariusgoore/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/webrick/server.rb:191:in `block in     start_thread'
4

4 に答える 4

0

私の推測では@tvshow、CharactersController#create アクションで変数を設定していないため、「nil:nilClass の未定義のメソッド文字」について不平を言っています。

于 2013-10-21T03:28:41.393 に答える
0

create メソッドで、次の行を置き換えます。

@character = @tvshow.characters.create(params[:character])

と

@character = Character.new(character_params)

于 2013-10-21T03:50:36.280 に答える
0

何らかの理由でコメントを公開できないため、これを回答として含めます。

上記で提案した変更を行い、(params[:id]) を文字コントローラーの新しいアクションの tvshow.find の引数として追加しました。

何らかの理由で、params[:id] が必要な tvshow_id を提供していないようです。次のエラー メッセージが表示されるようになりました。

15 # GET /characters/new 16 def new 17 @tvshow = Tvshow.find(params[:id]) # params にテレビ番組 ID が必要なので、検索ブロックで渡すことができます 18 @character = @tvshow.characters.build 19終わり

于 2013-10-21T15:49:19.353 に答える