0

RoR初心者です。プロファイル ページに特定のプロファイルに属するアイテムのリストが表示される基本的な Web アプリを作成しようとしています。

これまでのところ、私は持っています:

rails generate scaffold Profile name:string
rails generate scaffold Item description:string
rake db:migrate

プロファイル モデルの場合:has_many :itemsアイテム モデルの場合:belongs_to :profile

新しいプロファイルを作成しようとすると、次のエラーが表示されます。

undefined method `item' for #<Profile

プロファイル コントローラ

class ProfilesController < ApplicationController
  # GET /profiles
  # GET /profiles.json
  def index
    @profiles = profile.all

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

  # GET /profiles/1
  # GET /profiles/1.json
  def show
    @profile = profile.find(params[:id])

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

  # GET /profiles/new
  # GET /profiles/new.json
  def new
    @profile = profile.new

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

  # GET /profiles/1/edit
  def edit
    @profile = profile.find(params[:id])
  end

  # POST /profiles
  # POST /profiles.json
  def create
    @profile = profile.new(params[:profile])

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

  # PUT /profiles/1
  # PUT /profiles/1.json
  def update
    @profile = profile.find(params[:id])

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

  # DELETE /profiles/1
  # DELETE /profiles/1.json
  def destroy
    @profile = profile.find(params[:id])
    @profile.destroy

    respond_to do |format|
      format.html { redirect_to profiles_url }
      format.json { head :no_content }
    end
  end
end

プロフィール index.html.erb

<h1>Listing profiles</h1>

<table>
  <tr>
    <th>Name</th>
    <th></th>
    <th></th>
    <th></th>
  </tr>

<% @profiles.each do |profile| %>
  <tr>
    <td><%= profile.name %></td>
    <td><%= link_to 'Show', profile %></td>
    <td><%= link_to 'Edit', edit_profile_path(profile) %></td>
    <td><%= link_to 'Destroy', profile, method: :delete, data: { confirm: 'Are you sure?' } %></td>
  </tr>
<% end %>
</table>

<br />

<%= link_to 'New profile', new_profile_path %>

プロフィール _show.html.erb

<%= simple_form_for(@profile) do |f| %>
  <%= f.error_notification %>

  <div class="form-inputs">
    <%= f.input :name %>
  </div>

  <div class="form-inputs">
    <%= f.input :item %>
  </div>

  <div class="form-actions">
    <%= f.button :submit %>
  </div>
<% end %>

完全なエラー トレース:

activemodel (3.2.12) lib/active_model/attribute_methods.rb:407:in `method_missing'
activerecord (3.2.12) lib/active_record/attribute_methods.rb:149:in `method_missing'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:1161:in `value_before_type_cast'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:1149:in `value_before_type_cast'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:1043:in `block in to_input_field_tag'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:1043:in `fetch'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:1043:in `to_input_field_tag'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:692:in `text_field'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:1284:in `text_field'
simple_form (2.1.0) lib/simple_form/inputs/string_input.rb:13:in `input'
simple_form (2.1.0) lib/simple_form/wrappers/many.rb:29:in `block in render'
simple_form (2.1.0) lib/simple_form/wrappers/many.rb:27:in `each'
simple_form (2.1.0) lib/simple_form/wrappers/many.rb:27:in `render'
simple_form (2.1.0) lib/simple_form/wrappers/many.rb:29:in `block in render'
simple_form (2.1.0) lib/simple_form/wrappers/many.rb:27:in `each'
simple_form (2.1.0) lib/simple_form/wrappers/many.rb:27:in `render'
simple_form (2.1.0) lib/simple_form/wrappers/root.rb:15:in `render'
simple_form (2.1.0) lib/simple_form/form_builder.rb:117:in `input'
app/views/profiles/_form.html.erb:9:in `block in _app_views_profiles__form_html_erb___911765346923063960_2183588380'
actionpack (3.2.12) lib/action_view/helpers/capture_helper.rb:40:in `block in capture'
actionpack (3.2.12) lib/action_view/helpers/capture_helper.rb:187:in `with_output_buffer'
actionpack (3.2.12) lib/action_view/helpers/capture_helper.rb:40:in `capture'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:607:in `fields_for'
actionpack (3.2.12) lib/action_view/helpers/form_helper.rb:378:in `form_for'
simple_form (2.1.0) lib/simple_form/action_view_extensions/form_helper.rb:29:in `block in simple_form_for'
simple_form (2.1.0) lib/simple_form/action_view_extensions/form_helper.rb:48:in `with_simple_form_field_error_proc'
simple_form (2.1.0) lib/simple_form/action_view_extensions/form_helper.rb:28:in `simple_form_for'
app/views/profiles/_form.html.erb:1:in `_app_views_profiles__form_html_erb___911765346923063960_2183588380'
actionpack (3.2.12) lib/action_view/template.rb:145:in `block in render'
activesupport (3.2.12) lib/active_support/notifications.rb:125:in `instrument'
actionpack (3.2.12) lib/action_view/template.rb:143:in `render'
actionpack (3.2.12) lib/action_view/renderer/partial_renderer.rb:265:in `render_partial'
actionpack (3.2.12) lib/action_view/renderer/partial_renderer.rb:238:in `block in render'
actionpack (3.2.12) lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.12) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.12) lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
actionpack (3.2.12) lib/action_view/renderer/partial_renderer.rb:237:in `render'
actionpack (3.2.12) lib/action_view/renderer/renderer.rb:41:in `render_partial'
actionpack (3.2.12) lib/action_view/helpers/rendering_helper.rb:27:in `render'
app/views/profiles/new.html.erb:3:in `_app_views_profiles_new_html_erb___3444063506780261827_2182112400'
actionpack (3.2.12) lib/action_view/template.rb:145:in `block in render'
activesupport (3.2.12) lib/active_support/notifications.rb:125:in `instrument'
actionpack (3.2.12) lib/action_view/template.rb:143:in `render'
actionpack (3.2.12) lib/action_view/renderer/template_renderer.rb:47:in `block (2 levels) in render_template'
actionpack (3.2.12) lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.12) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.12) lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
actionpack (3.2.12) lib/action_view/renderer/template_renderer.rb:46:in `block in render_template'
actionpack (3.2.12) lib/action_view/renderer/template_renderer.rb:54:in `render_with_layout'
actionpack (3.2.12) lib/action_view/renderer/template_renderer.rb:45:in `render_template'
actionpack (3.2.12) lib/action_view/renderer/template_renderer.rb:18:in `render'
actionpack (3.2.12) lib/action_view/renderer/renderer.rb:36:in `render_template'
actionpack (3.2.12) lib/action_view/renderer/renderer.rb:17:in `render'
actionpack (3.2.12) lib/abstract_controller/rendering.rb:110:in `_render_template'
actionpack (3.2.12) lib/action_controller/metal/streaming.rb:225:in `_render_template'
actionpack (3.2.12) lib/abstract_controller/rendering.rb:103:in `render_to_body'
actionpack (3.2.12) lib/action_controller/metal/renderers.rb:28:in `render_to_body'
actionpack (3.2.12) lib/action_controller/metal/compatibility.rb:50:in `render_to_body'
actionpack (3.2.12) lib/abstract_controller/rendering.rb:88:in `render'
actionpack (3.2.12) lib/action_controller/metal/rendering.rb:16:in `render'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:40:in `block (2 levels) in render'
activesupport (3.2.12) lib/active_support/core_ext/benchmark.rb:5:in `block in ms'
/usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/benchmark.rb:295:in `realtime'
activesupport (3.2.12) lib/active_support/core_ext/benchmark.rb:5:in `ms'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:40:in `block in render'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:83:in `cleanup_view_runtime'
activerecord (3.2.12) lib/active_record/railties/controller_runtime.rb:24:in `cleanup_view_runtime'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:39:in `render'
actionpack (3.2.12) lib/action_controller/metal/implicit_render.rb:10:in `default_render'
actionpack (3.2.12) lib/action_controller/metal/mime_responds.rb:196:in `respond_to'
app/controllers/profiles_controller.rb:29:in `new'
actionpack (3.2.12) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (3.2.12) lib/abstract_controller/base.rb:167:in `process_action'
actionpack (3.2.12) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (3.2.12) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (3.2.12) lib/active_support/callbacks.rb:414:in `_run__312850119216024862__process_action__607287929354052739__callbacks'
activesupport (3.2.12) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.12) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
activesupport (3.2.12) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.12) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.2.12) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.12) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.2.12) lib/action_controller/metal/params_wrapper.rb:207:in `process_action'
activerecord (3.2.12) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (3.2.12) lib/abstract_controller/base.rb:121:in `process'
actionpack (3.2.12) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.2.12) lib/action_controller/metal.rb:203:in `dispatch'
actionpack (3.2.12) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.2.12) lib/action_controller/metal.rb:246:in `block in action'
actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:36:in `call'
journey (1.0.4) lib/journey/router.rb:68:in `block in call'
journey (1.0.4) lib/journey/router.rb:56:in `each'
journey (1.0.4) lib/journey/router.rb:56:in `call'
actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:601:in `call'
warden (1.2.1) lib/warden/manager.rb:35:in `block in call'
warden (1.2.1) lib/warden/manager.rb:34:in `catch'
warden (1.2.1) lib/warden/manager.rb:34:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
rack (1.4.5) lib/rack/etag.rb:23:in `call'
rack (1.4.5) lib/rack/conditionalget.rb:25:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/head.rb:14:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/flash.rb:242:in `call'
rack (1.4.5) lib/rack/session/abstract/id.rb:210:in `context'
rack (1.4.5) lib/rack/session/abstract/id.rb:205:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/cookies.rb:341:in `call'
activerecord (3.2.12) lib/active_record/query_cache.rb:64:in `call'
activerecord (3.2.12) lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.12) lib/active_support/callbacks.rb:405:in `_run__1382692569756144731__call__1219384665416315194__callbacks'
activesupport (3.2.12) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.12) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
activesupport (3.2.12) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.12) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/reloader.rb:65:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
railties (3.2.12) lib/rails/rack/logger.rb:32:in `call_app'
railties (3.2.12) lib/rails/rack/logger.rb:16:in `block in call'
activesupport (3.2.12) lib/active_support/tagged_logging.rb:22:in `tagged'
railties (3.2.12) lib/rails/rack/logger.rb:16:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/request_id.rb:22:in `call'
rack (1.4.5) lib/rack/methodoverride.rb:21:in `call'
rack (1.4.5) lib/rack/runtime.rb:17:in `call'
activesupport (3.2.12) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.4.5) lib/rack/lock.rb:15:in `call'
actionpack (3.2.12) lib/action_dispatch/middleware/static.rb:62:in `call'
railties (3.2.12) lib/rails/engine.rb:479:in `call'
railties (3.2.12) lib/rails/application.rb:223:in `call'
rack (1.4.5) lib/rack/content_length.rb:14:in `call'
railties (3.2.12) lib/rails/rack/log_tailer.rb:17:in `call'
rack (1.4.5) lib/rack/handler/webrick.rb:59:in `service'
/usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'
/usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'
/usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'
4

2 に答える 2

1

が機能するには、モデルhas_many :itemsに が必要です。profile_id:integerItem

次のコマンドを実行することで達成できます

rails g migration add_profile_id_to_items profile_id:integer
rake db:migrate

これにより、関連付けに必要な外部キーが作成されます。

その後、このようなことができるはずです

@profile = Profile.create name: "MyProfile"
@item = @profile.items.build description: "This is my awesome item"
@item.save

プロファイルの項目を作成する方法はいくつかありますが、それが最も簡単な方法です。次に、これらのアイテムを取得するには、次のようにします

@profile = Profile.find(some_id)
@items = Item.where(profile_id: @profile.id).all

また

@profile = Profile.find(some_id)
@items = @profile.items
于 2013-03-22T02:00:24.797 に答える
0

まず、Profile オブジェクトには「item」フィールドがありません。次のコマンドを実行して、オブジェクトの属性を確認します。

rails console
Profile.connection
Profile

またはあなたのdb/schema.rbファイルにアクセスしてください

オブジェクトのハッシュに属性 :item がないことがわかります。

プロファイルのアイテムをビューに表示したいと思うでしょうshow.html.erb。Itemただし、最初に、それが属するプロファイルの を次のように作成する必要があります。

item = Item.new(description: "Test description", profile_id: 1)

次に、次のことができます。

Profile.first.items

次に、コントローラーにエラーがあります。オブジェクトのクラスは大文字にする必要があるため、次のようになります。

rails console
profile = profile.new(name: "Test profile")

エラーが発生します

undefined method `new' for nil:NilClass
于 2017-03-01T14:55:02.160 に答える