undefined方法`each'代表“27”：String

Question

我正在尝试让一些用户在团队中注册，我更新了我的代码，以便团队可以注册，但是出现以下错误：

undefined method `each' for "27":String
NoMethodError in TeamsController#create 

我的代码如下：

class Team<ActiveRecord::Base

belongs_to :league
belongs_to :seed
has_many :speakers do 
def user(level="1")
    find_by(level: level).user
  end
 end
end

我的用户模型如下所示：

class User < ActiveRecord::Base

belongs_to :team

end

用户模型：

class User<ActiveRecord::Base
has_many :speaking_engagements, class_name: "Speaker"
has_many :teams , through: :speaking_engagements
end

演讲者模特：

class Speaker < ActiveRecord::Base
    belongs_to :team
    belongs_to :user
end

团队控制员：

class TeamsController<ApplicationController


def new
    @seed=Seed.find_by_id(params[:seed_id])
    @league=current_admin.league
      @team=current_admin.league.teams.build(:seed_id=>@seed,:approved=>false)
    @usernames= @mca.connections.connected.each do |x| x.user end
end

def create
    @league=current_admin.league
    **@team = @league.teams.build(team_params)** #problem appears to be here

  if @team.save
    flash[:notice] = "Team Request Sent!."
    redirect_to '/'
  else
    flash[:error] = "Unable to request team."
    redirect_to :back
  end
end

表格如下：

<div class="panel-body">
    <div class="container">
        <%= form_for @team do |f| %>
            <%= f.hidden_field :seed_id, :value => @seed.id %>
            <%= f.hidden_field :league_id, :value => @league.id %>

            <div class="row">
                <!-- <div class="col-md-8"> -->
                <div class="form-group">

                    <%= f.collection_select :speakers, @usernames,:user_id,:fullname, multiple:true %>
                </div>



                <!-- </div> -->
            </div>


            <div class="actions">
                <%= f.submit "Create" , class:"btn btn-primary" %>
            </div>

        <% end %>
    </div>
</div>

演讲者迁移：

class CreateSpeekers < ActiveRecord::Migration
 def change
   create_table :speakers do |t|
    t.integer :team_id
    t.integer :user_id
    t.integer :level

    t.timestamps null: false
   end
 end
end

我已经被这个错误困住了很长一段时间了，我非常感谢任何帮助！

完整追踪：

activerecord (4.2.0) lib/active_record/associations/collection_association.rb:355:in `replace'
activerecord (4.2.0) lib/active_record/associations/collection_association.rb:47:in `writer'
activerecord (4.2.0) lib/active_record/associations/builder/association.rb:123:in `speekers='
activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `public_send'
 activerecord (4.2.0) lib/active_record/attribute_assignment.rb:54:in `_assign_attribute'
activerecord (4.2.0) lib/active_record/attribute_assignment.rb:41:in `block in assign_attributes'
actionpack (4.2.0) lib/action_controller/metal/strong_parameters.rb:183:in `each_pair'
actionpack (4.2.0) lib/action_controller/metal/strong_parameters.rb:183:in `each_pair'
activerecord (4.2.0) lib/active_record/attribute_assignment.rb:35:in `assign_attributes'
activerecord (4.2.0) lib/active_record/core.rb:557:in `init_attributes'
activerecord (4.2.0) lib/active_record/core.rb:280:in `initialize'
activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new'
activerecord (4.2.0) lib/active_record/inheritance.rb:61:in `new'
activerecord (4.2.0) lib/active_record/reflection.rb:131:in `build_association'
activerecord (4.2.0) lib/active_record/associations/association.rb:247:in `build_record'
activerecord (4.2.0) lib/active_record/associations/collection_association.rb:136:in `build'
activerecord (4.2.0) lib/active_record/associations/collection_proxy.rb:254:in `build'
app/controllers/teams_controller.rb:13:in `create'
actionpack (4.2.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.2.0) lib/abstract_controller/base.rb:198:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.2.0) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
activesupport (4.2.0) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `_run_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_process_action_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.0) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `instrument'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
activerecord (4.2.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.2.0) lib/abstract_controller/base.rb:137:in `process'
actionview (4.2.0) lib/action_view/rendering.rb:30:in `process'
actionpack (4.2.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.2.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.2.0) lib/action_controller/metal.rb:236:in `block in action'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:42:in `serve'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:43:in `block in serve'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `each'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `serve'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:802:in `call'
warden (1.2.3) lib/warden/manager.rb:35:in `block in call'
warden (1.2.3) lib/warden/manager.rb:34:in `catch'
warden (1.2.3) lib/warden/manager.rb:34:in `call'
rack (1.6.4) lib/rack/etag.rb:24:in `call'
rack (1.6.4) lib/rack/conditionalget.rb:38:in `call'
rack (1.6.4) lib/rack/head.rb:13:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/flash.rb:260:in `call'
rack (1.6.4) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.6.4) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/cookies.rb:560:in `call'
activerecord (4.2.0) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.2.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:647:in `call'
activerecord (4.2.0) lib/active_record/migration.rb:378:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `_run_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_call_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
web-console (2.2.1) lib/web_console/middleware.rb:39:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.0) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.0) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.0) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/static.rb:113:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.0) lib/rails/engine.rb:518:in `call'
railties (4.2.0) lib/rails/application.rb:164:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
/home/shyam/.rbenv/versions/2.2.1/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
/home/shyam/.rbenv/versions/2.2.1/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
/home/shyam/.rbenv/versions/2.2.1/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'

Answer 1

问题在于"27"（用户ID）被指定为团队的speakers关联。这是错的。应为speakers分配Speaker个实例。

不幸的是，此时此刻变得艰难。

您真正需要做的是使用嵌套属性来构建所需的扬声器记录，其中每个发言者分配一个选定的用户ID。在UI中有很多方法可以解决这个问题。有许多使用嵌套属性的很好的例子，包括这个Railscasts episode

Answer 2

has_many为您提供了许多有趣的方法，包括collection_singular_ids和collection_singular_ids=。其中的要点意味着你应该能够利用那个吸气剂和放大器。像你这样的表格中的setter

<%= f.collection_select :speaker_ids, @usernames, :user_id, :fullname, multiple: true %>

Answer 3

我找到了问题的答案，感谢关注@WizardOfOgz评论， 所以我做了以下事情：

在我的teams_controller.rb中添加了以下允许的参数：

params.require(:team).permit(:user_id, :league_id,:seed_id, :approved, :speakers_attributes=>[:team_id,:user_id])

端

然后，

在我的团队中.rb添加了以下内容：

accepts_nested_attributes_for :speakers

此外，在团队的表单中添加了嵌套属性：

(in app/views/teams/_form.html.rb )

<h2>Speakers</h2>
    <%= f.fields_for :speakers do |ff| %>
    <div>
    <%= ff.collection_select :user_id, @usernames,:user_id,:fullname%>
     </div>
    <% end %>

因为我想要3个发言者，所以我在helpers / form_helpers中创建了以下函数：

module FormHelper

def setup_team(team)

3.times{
    team.speakers.build
}
    team
  end

end

为我解决了这个问题，

感谢@WizardOfOgz和@RichPeck 这个真的真的很有帮助： http://www.sitepoint.com/complex-rails-forms-with-nested-attributes/