ID无零has_many：通过但在参数存在：ID

Question

我有has_many：通过关系的3个模型。用户，活动和图库。在方法new和create在gallery_controller我需要得到event_id，但是我得到一个零的event_id。但在Mozilla控制台和参数中，存在该id。我不是我做错了什么？

我也想知道new和create动作的结构是否正常？我想在创建之前添加一个活动画廊，并且在current_user画廊中同时添加一个活动画廊，但我无法通过之前的问题对其进行测试。

谢谢和欢呼。

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 

Gallery_controller

def new 
@event = Event.find(params[:event_id]) 
@galery = Gallery.new 
respond_to do |format | 
format.html# new.html.erb 
format.json { 
render json: @gallery 
} 
end 
end 




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

respond_to do |format | 
    if@ gallery.save 

    if params[: images]# The magic is here;) 
    params[: images].each { | image | @gallery.pictures.create(image: image) 
    } 
end 

    def gallery_params 
    params.require(:gallery).permit(:description, 
           :name, 
           :pictures, 
           :event_attributes => [], 
           :user_attributes => [], 
           ) 
end 

form_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 %> 

路线

resources :events do 
    resources :galleries 
    end 

图片错误

http://i.stack.imgur.com/mk1Ti.png

Answer 1

我想我找到了你的问题。对我来说，似乎有更多的问题。但最初解决你的问题：你需要补充事项标识允许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 => [], 
           ) 

而且您的形式并不内容的权利实例变量。差异在这里：

<%= 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 

建议的方式，以保持外键隐藏，以及你从事件构建也：

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

然后在你的表单中添加作为隐藏的外键字段：

<%= f.hidden_field :event_id %> 

Answer 2

这个错误是因为你在你的new方法的错字。

此行

@galery = Gallery.new 

应该

@gallery = Gallery.new 

而且你create方法有一些错误，其需要修理。

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 

，也是你的gallery_params需要调整

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

你不希望包括:event_attributes => []，:user_attributes => []除非你的窗体有nested fields为users和events需要被保存。