嵌套字段和强参数

Question

我在Rails 4中遇到了一个复杂的问题,我将在下面介绍.我使用简单的形式和awesome_nested_fields宝石.

我的应用程序中有一些带有一些字段的事件

这是我在working_nested_attributes实现之前的工作event_controller参数:

private

  def event_params
    params.require(:event).permit(:title, :description, :type_id, :price, :program,
                                  :start_date, :end_date, :image, category_ids: [])
  end

现在我想在我的活动中添加一些发言者,并让用户决定每个活动他想要多少个发言者.因此,根据他们的文档,我添加了嵌套字段gem并使扬声器成为嵌套字段.

Event.rb

class Event < ActiveRecord::Base
  has_many :speakers
  accepts_nested_attributes_for :speakers, allow_destroy: true
end

Speaker.rb

class Speaker < ActiveRecord::Base
  belongs_to :event
end

添加扬声器(在我的添加事件simple_form_for中):

  <%= f.nested_fields_for :speakers do |f| %>
      <fieldset class="item">
        <%= f.label :name %>
        <%= f.text_field :name %>

        <a href="#" class="remove">remove</a>

        <%= f.hidden_field :id %>
        <%= f.hidden_field :_destroy %>
    </fieldset>
  <% end %>

更新强参数的控制器:

private

  def event_params
    params.require(:event).permit(:title, :description, :type_id, :price, :program,
                                  :start_date, :end_date, :image, category_ids: [],
                                  speakers_attributes: [ :name ])
  end

现在,当我启动我的应用程序时,在创建新事件时,我得到了:

can't write unknown attribute `event_id'

如果我删除了

speakers_attributes: [ :name ]

从强大的参数我将能够创建我的事件,但是当我试图查看或编辑它时,我会得到

SQLite3::SQLException: no such column: speakers.event_id: SELECT "speakers".* FROM "speakers"  WHERE "speakers"."event_id" = ?

当然,数据库中没有创建扬声器.

>> s = Speaker.first
=> nil

我将不胜感激任何帮助或建议.谢谢!

=====

更新了重复问题

事件控制器

  def update
    @event = Event.find(params[:id])

    if @event.update(event_params)
      flash[:success] = "Event updated"
      redirect_to @event
    else
      render @event  
    end
  end

event.rb

class Event < ActiveRecord::Base

  belongs_to :type

  has_many :categorizations
  has_many :categories, through: :categorizations
  has_many :speakers
  accepts_nested_attributes_for :speakers, allow_destroy: true

  @today = Date.today

  def self.future_events
    order('start_date ASC').where('start_date >= ?', @today)
  end

  scope :current_events,  lambda { where('start_date < ? and end_date > ?', @today, @today) }
  scope :past_events,     lambda { order('end_date DESC').where('end_date < ?', @today) }

  scope :future_by_type,   lambda { |type| order('start_date ASC').where('type_id = ? and start_date >= ?', type, @today) }
  scope :current_by_type,  lambda { |type| order('start_date ASC').where('type_id = ? and start_date < ? and end_date > ?', type, @today, @today) }
  scope :past_by_type,     lambda { |type| order('start_date ASC').where('type_id = ? and end_date < ?', type, @today) }

  validates :title, presence: true

  mount_uploader :image, ImageUploader

  before_save :define_end_date
  before_save :zero_price

    private

      def define_end_date
        self.end_date ||= self.start_date
      end

      def zero_price
        if self.price.empty?
          self.price = 0
        end 
      end
end

Answer 1

现在我考虑一下,它可能与强参数有关.要使更新生效,您还需要允许id属性.在您的许可证参数中添加id speakers以及将要更新的任何其他嵌套的嵌套资源.

请尝试一下:

def event_params
  params.require(:event).permit(:title, :description, :type_id, :price, :program,
                              :start_date, :end_date, :image, category_ids: [],
                              speakers_attributes: [ :id, :name ])
end