联系人#new中的NoMethodError

时间：2015-06-19 23:40:23

标签： ruby-on-rails

我正在按照“编码手册”中的教程进行操作，并尝试创建联系表单。看起来我已经有了一切，但它不会起作用。

contacts_controller 

class ContactsController < ApplicationController
  def new
    @contact = Contact.new
  end

  def create
  end
end


class CreateContacts < ActiveRecord::Migration
  def change
    create_table :contacts do |t|
      t.string :name
      t.string :email
      t.text :comments
      t.timestamps
    end
  end
end

这是 new.html.erb 

<div class="row">
  <div class="col-md-4 col-md-offset-4">
    <div class="well">
      <%= form_for @contact do |f| %>
        <div class="form-group">
          <%= f.label :name %>
          <%= f.text_field :name, class: 'form-control' %>
        </div>
        <div class="form-group">
          <%= f.label :email %>
          <%= f.email_field :email, class: 'form-control' %>
        </div>
        <div class="form-group">
          <%= f.label :comments %>
          <%= f.text_area :comments, class: 'form-control' %>
        </div>
        <%= f.submit 'Submit', class: 'btn btn-default' %>
      <% end %>
    </div>
  </div>
</div>

我收到了NoMethodError in Contacts#new

堆栈跟踪

activemodel (4.1.0) lib/active_model/attribute_methods.rb:435:in `method_missing'
activerecord (4.1.0) lib/active_record/attribute_methods.rb:206:in `method_missing'
actionview (4.1.0) lib/action_view/helpers/tags/base.rb:28:in `value'
actionview (4.1.0) lib/action_view/helpers/tags/base.rb:37:in `value_before_type_cast'
actionview (4.1.0) lib/action_view/helpers/tags/text_field.rb:9:in `block in render'
actionview (4.1.0) lib/action_view/helpers/tags/text_field.rb:9:in `fetch'
actionview (4.1.0) lib/action_view/helpers/tags/text_field.rb:9:in `render'
actionview (4.1.0) lib/action_view/helpers/form_helper.rb:771:in `text_field'
actionview (4.1.0) lib/action_view/helpers/form_helper.rb:1258:in `text_field'
app/views/contacts/new.html.erb:4:in `block in _app_views_contacts_new_html_erb__916588012054069058_69974500316060'
actionview (4.1.0) lib/action_view/helpers/capture_helper.rb:38:in `block in capture'
actionview (4.1.0) lib/action_view/helpers/capture_helper.rb:200:in `with_output_buffer'
actionview (4.1.0) lib/action_view/helpers/capture_helper.rb:38:in `capture'
actionview (4.1.0) lib/action_view/helpers/form_helper.rb:434:in `form_for'
app/views/contacts/new.html.erb:2:in `_app_views_contacts_new_html_erb__916588012054069058_69974500316060'
actionview (4.1.0) lib/action_view/template.rb:145:in `block in render'
activesupport (4.1.0) lib/active_support/notifications.rb:161:in `instrument'
actionview (4.1.0) lib/action_view/template.rb:339:in `instrument'
actionview (4.1.0) lib/action_view/template.rb:143:in `render'
actionview (4.1.0) lib/action_view/renderer/template_renderer.rb:55:in `block (2 levels) in render_template'
actionview (4.1.0) lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
activesupport (4.1.0) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.1.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.1.0) lib/active_support/notifications.rb:159:in `instrument'
actionview (4.1.0) lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
actionview (4.1.0) lib/action_view/renderer/template_renderer.rb:54:in `block in render_template'
actionview (4.1.0) lib/action_view/renderer/template_renderer.rb:62:in `render_with_layout'
actionview (4.1.0) lib/action_view/renderer/template_renderer.rb:53:in `render_template'
actionview (4.1.0) lib/action_view/renderer/template_renderer.rb:17:in `render'
actionview (4.1.0) lib/action_view/renderer/renderer.rb:42:in `render_template'
actionview (4.1.0) lib/action_view/renderer/renderer.rb:23:in `render'
actionview (4.1.0) lib/action_view/rendering.rb:99:in `_render_template'
actionpack (4.1.0) lib/action_controller/metal/streaming.rb:217:in `_render_template'
actionview (4.1.0) lib/action_view/rendering.rb:82:in `render_to_body'
actionpack (4.1.0) lib/action_controller/metal/rendering.rb:32:in `render_to_body'
actionpack (4.1.0) lib/action_controller/metal/renderers.rb:32:in `render_to_body'
actionpack (4.1.0) lib/abstract_controller/rendering.rb:25:in `render'
actionpack (4.1.0) lib/action_controller/metal/rendering.rb:16:in `render'
actionpack (4.1.0) lib/action_controller/metal/instrumentation.rb:41:in `block (2 levels) in render'
activesupport (4.1.0) lib/active_support/core_ext/benchmark.rb:12:in `block in ms'
/home/action/.parts/packages/ruby2.1/2.1.1/lib/ruby/2.1.0/benchmark.rb:294:in `realtime'
activesupport (4.1.0) lib/active_support/core_ext/benchmark.rb:12:in `ms'
actionpack (4.1.0) lib/action_controller/metal/instrumentation.rb:41:in `block in render'
actionpack (4.1.0) lib/action_controller/metal/instrumentation.rb:84:in `cleanup_view_runtime'
activerecord (4.1.0) lib/active_record/railties/controller_runtime.rb:25:in `cleanup_view_runtime'
actionpack (4.1.0) lib/action_controller/metal/instrumentation.rb:40:in `render'
actionpack (4.1.0) lib/action_controller/metal/implicit_render.rb:10:in `default_render'
actionpack (4.1.0) lib/action_controller/metal/implicit_render.rb:5:in `send_action'
actionpack (4.1.0) lib/abstract_controller/base.rb:189:in `process_action'
actionpack (4.1.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.1.0) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
activesupport (4.1.0) lib/active_support/callbacks.rb:113:in `call'
activesupport (4.1.0) lib/active_support/callbacks.rb:113:in `call'
activesupport (4.1.0) lib/active_support/callbacks.rb:229:in `block in halting'
activesupport (4.1.0) lib/active_support/callbacks.rb:229:in `call'
activesupport (4.1.0) lib/active_support/callbacks.rb:229:in `block in halting'
activesupport (4.1.0) lib/active_support/callbacks.rb:166:in `call'
activesupport (4.1.0) lib/active_support/callbacks.rb:166:in `block in halting'
activesupport (4.1.0) lib/active_support/callbacks.rb:166:in `call'
activesupport (4.1.0) lib/active_support/callbacks.rb:166:in `block in halting'
activesupport (4.1.0) lib/active_support/callbacks.rb:166:in `call'
activesupport (4.1.0) lib/active_support/callbacks.rb:166:in `block in halting'
activesupport (4.1.0) lib/active_support/callbacks.rb:86:in `call'
activesupport (4.1.0) lib/active_support/callbacks.rb:86:in `run_callbacks'
actionpack (4.1.0) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.1.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.1.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.1.0) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.1.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.1.0) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.1.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.1.0) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
activerecord (4.1.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.1.0) lib/abstract_controller/base.rb:136:in `process'
actionview (4.1.0) lib/action_view/rendering.rb:30:in `process'
actionpack (4.1.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.1.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.1.0) lib/action_controller/metal.rb:231:in `block in action'
actionpack (4.1.0) lib/action_dispatch/routing/route_set.rb:80:in `call'
actionpack (4.1.0) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
actionpack (4.1.0) lib/action_dispatch/routing/route_set.rb:48:in `call'
actionpack (4.1.0) lib/action_dispatch/journey/router.rb:71:in `block in call'
actionpack (4.1.0) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.1.0) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.1.0) lib/action_dispatch/routing/route_set.rb:676:in `call'
rack (1.5.5) lib/rack/etag.rb:23:in `call'
rack (1.5.5) lib/rack/conditionalget.rb:25:in `call'
rack (1.5.5) lib/rack/head.rb:11:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/flash.rb:254:in `call'
rack (1.5.5) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.5.5) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/cookies.rb:560:in `call'
activerecord (4.1.0) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.1.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:621:in `call'
activerecord (4.1.0) lib/active_record/migration.rb:380:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.1.0) lib/active_support/callbacks.rb:82:in `run_callbacks'
actionpack (4.1.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.1.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.1.0) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.1.0) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.1.0) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.1.0) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.1.0) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.5.5) lib/rack/methodoverride.rb:21:in `call'
rack (1.5.5) lib/rack/runtime.rb:17:in `call'
activesupport (4.1.0) lib/active_support/cache/strategy/local_cache_middleware.rb:26:in `call'
rack (1.5.5) lib/rack/lock.rb:17:in `call'
actionpack (4.1.0) lib/action_dispatch/middleware/static.rb:64:in `call'
rack (1.5.5) lib/rack/sendfile.rb:112:in `call'
railties (4.1.0) lib/rails/engine.rb:514:in `call'
railties (4.1.0) lib/rails/application.rb:144:in `call'
rack (1.5.5) lib/rack/lock.rb:17:in `call'
rack (1.5.5) lib/rack/content_length.rb:14:in `call'
rack (1.5.5) lib/rack/handler/webrick.rb:60:in `service'
/home/action/.parts/packages/ruby2.1/2.1.1/lib/ruby/2.1.0/webrick/httpserver.rb:138:in `service'
/home/action/.parts/packages/ruby2.1/2.1.1/lib/ruby/2.1.0/webrick/httpserver.rb:94:in `run'
/home/action/.parts/packages/ruby2.1/2.1.1/lib/ruby/2.1.0/webrick/server.rb:295:in `block in start_thread'

3 个答案:

答案 0 :(得分：0)

试试这个，看它是否有效......

<%= form_for Contact.new do |f| %>

但是，请添加您的contacts_controller.rb代码。我觉得你没有在那里指定你的new，show和create行动。

答案 1 :(得分：0)

您必须更改控制器代码create操作。新动作不会创造新纪录。您需要在create action中编写该逻辑。将代码控制器代码更改为此。并尝试。

class ContactsController < ApplicationController
  def new
    @contact = Contact.new
  end

  def create
   @contact = Contact.build(contact_params)
  end
end

# define your contact params here

private

 def contact_params
   params.require(:contact).permit(:name, :email, :comments)
 end

答案 2 :(得分：-1)

在你的new.html.erb中。 改变

<%= form_for @contact do |f| %>

到

<%= form_for "contacts" do |f| %>

这似乎解决了我的问题...

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