Ruby on rails id nil有多个：到，但参数中存在：id

我有3个型号，有很多：通过关系。用户、事件和库。在

gallery\u controller

中的

new

和

create

方法中，我需要获取事件id，但是我得到了一个nil事件id。但是在mozilla控制台和参数中，存在id。我不知道我做错了什么

我还想知道

new

和

create

操作的结构是否正常？我想在创建之前为一个事件添加一个库，同时在当前用户库中，我无法通过前面的问题测试它

谢谢，干杯

class Event < ActiveRecord::Base
has_many: galleries
has_many: users, through: : galleries, : source => : users, : dependent => : destroy
accepts_nested_attributes_for: users
accepts_nested_attributes_for: galleries

end


class User < ActiveRecord::Base
has_many :galleries
has_many :events, through: :galleries, :dependent => :destroy
accepts_nested_attributes_for :events
accepts_nested_attributes_for :galleriesenter code here
end

class Gallery < ActiveRecord::Base

 has_many :pictures, :dependent => :destroy
 belongs_to :event
 belongs_to :user


 end

形成新画廊

<%= form_for [@event,@gallery], :html => { :class => 'form-horizontal', multipart: true } do |f| %>
   <div class="control-group">
     <%= f.label :name, :class => 'control-label' %>
      <div class="controls">
       <%= f.text_field :name, :class => 'text_field' %>
      </div>
    </div>
    <div class="control-group">
      <%= f.label :description, :class => 'control-label' %>
       <div class="controls">
         <%= f.text_field :description, :class => 'text_field' %>
    </div>
   </div>
 <div class="control-group">
   <%= f.label :pictures, :class => 'control-label' %>
     <div class="controls">

  <%= file_field_tag "images[]", type: :file, multiple: true %>
  </div>
 </div>
 <div class="form-actions">
 <%= f.submit  :class => 'btn btn-primary' %>
  <%= link_to t('.cancel', :default => t("helpers.links.cancel")),
  galleries_path, :class => 'btn btn-mini' %>
  </div>
  <% end %>

图像错误

---

错误是因为您的

新方法中有一个输入错误

这条线

@galery = Gallery.new

应该是

@gallery = Gallery.new

此外，您的
create
方法有一些错误，需要修复

def create
 @event = Event.find(params[:event_id])
 @gallery = @event.galleries.build(gallery_params)
 @gallery.user = current_user

 respond_to do |format|
  if @gallery.save

    if params[:images]
     params[:images].each { |image| @gallery.pictures.create(image: image)}
    end

    format.html { redirect_to @gallery, notice: 'Gallery was successfully created.' }
    format.json { render json: @gallery, status: :created, location: @gallery }
  else
    format.html { render :new }
    format.json { render json: @gallery.errors, status: :unprocessable_entity }
  end
 end
end

您的
库参数也需要调整

def gallery_params
  params.require(:gallery).permit(:description,:name)
end

你不想包括
：event\u attributes=>[]
，
：user\u attributes=>[]
，除非你的表单中有
嵌套字段
用于
用户
和需要保存的
事件
。
我想我发现了你的问题。对我来说，似乎还有更多的问题。但首先要解决您的问题：您需要添加event_id以允许params方法：

  params.require(:gallery).permit(:description,
                                :name,
                                :pictures,
                                :event_id, # this line should be here if your foreign key is event_id for gallery model.
                                :event_attributes => [],
                                :user_attributes => [],
                               )

此外，表单中没有包含正确的实例变量。不同之处：

<%= form_for [@event,@gallery], :html => { :class => 'form-horizontal', multipart: t # you wrote @gallery here but in your controller you wrote:

# controller's action:
@galery = Gallery.new

然后在表单中，将外键字段添加为隐藏：

<%= f.hidden_field :event_id %> 



<%= form_for [@event,@gallery], :html => { :class => 'form-horizontal', multipart: t # you wrote @gallery here but in your controller you wrote:

# controller's action:
@galery = Gallery.new

@event = Event.find(params[:event_id])
@gallery = @event.gallaries.build #note: 1.spelling and 2. building from @event object

<%= f.hidden_field :event_id %>