Rails 3.2 has_many通过表单提交

Question

我有一个has_many：通过表单我无法获得额外的属性发布到数据库。我弄错了某处的参数名称。我可以获得外键发布，但我有另一个属性，我试图追踪连接表中。请记住，这是一个100％基于ajax的表单。这是我所知道的

编辑： 经过研究类似的问题，我明白我应该建立表单属性，但我发现的代码由于某种原因不起作用。这里有一些资源。

http://railsforum.com/viewtopic.php?id=20203

Rails 3, nested multi-level forms and has_many through

我不明白的是，安装在product_ids内置轨。这些值发布。为什么将quantity_shipped属性附加到该数组很难？

Models and Relationships 
    Shipment has_many :products :through => :product_shipments 
    Product has_many :shipments :through => :product_shipments 
    ProductShipments belongs_to :shipment, belongs_to :product 

ProductShipments table 
    t.integer :shipment_id 
    t.integer :product_id 
    t.integer :qty_shipped <-- This is the Problem Child 

这部分是通过几次循环显示某个供应商的所有产品。它为product_ids生成一个数组，为product_shipments数量生成另一个数组。

_product_shipments.html.erb。

<div id="product_shipments_container"> 
<h3>Assign Products to Ship</h3> 
<ul class="product_shipments" id="product_shipments"> 
    <% Product.by_client(@client_id).each do |product| %> 
    <%= content_tag_for :li, product, :value => product.id do %> 
     <%= hidden_field_tag("shipment[product_ids][]", product.id) %> 
     <%= product.product_name %><%= text_field_tag("product_shipments[qty_shipped]")%> <--This is where the issue lies 
    <% end %> 
    <% end %> 
</ul> 
</div> 

这是当表单提交相关的POST数据

"product_ids"=>["1", "3"]}, "product_shipments"=>{"qty_shipped"=>["32", "23"]} 

这是发送到数据库

INSERT INTO `product_shipments` (`product_id`, `qty_shipped`, `shipment_id`) 
VALUES (1, NULL, 155) 
INSERT INTO `product_shipments` (`product_id`, `qty_shipped`, `shipment_id`) 
VALUES (3, NULL, 155) 

这里SQL是在我的控制器的动作

def create 
@shipment = Shipment.new(params[:shipment]) 

@product_shipments = @shipment.product_shipments.build(params[:product_shipments]) 

[：qty_shipped ]）< - 不正确的，但是这是我走到这一步，如果 @ shipment.save respond_with @shipment，：位置=> shipments_url 其他 闪光灯[：声明] = “不保存” 结束 结束

这是我遇到的最后一个问题。

TypeError (can't convert Symbol into Integer): 
    app/controllers/shipments_controller.rb:24:in `[]' 
    app/controllers/shipments_controller.rb:24:in `create' 

GOT IT。使用下面的正确答案进行更改后。我能控制纠正以下

@product_shipments = @shipment.product_shipments.build(params[:product_shipments]) 

Answer 1

最简单的解决方案的形式是，你需要生成的数组哈希看起来像

:product_shipments=>[{:product_id=>1, :qty_shipped=>32},{:product_id=>3, :qty_shipped=>23}] 

而不是两组哈希:shipment=>{:product_ids=>[1,3]}和:product_shipments=>[:qty_shipped=>[32,23]]。

要做到这一点，您的视图代码更改为

<%= hidden_field_tag("product_shipments[][product_id]", product.id) %> 
<%= product.product_name %><%= text_field_tag("product_shipments[][qty_shipped]")%> 

那么你的控制器动作将正常运行是。

Answer 2

你“创造”的行动可以是简单的

def create 
    @shipment = Shipment.new(params[:shipment]) 

    if @shipment.save 
    # success 
    else 
    # failure 
    end 
end 

如果使用嵌套的属性，通过新的出货纪录创造shipment_products

。要做到这一点，添加以下的货物模型

class Shipment 
    attr_accessible :shipment_products_attributes 
    accepts_nested_attributes_for :shipment_products 
end 

通过在视图中使用fields_for，这将允许装运接受params[:shipment][:shipment_products_attributes]和传递这些在其shipment_products。

在新的动作，你可以不喜欢

def new 
    @shipment = Shipment.new 
    # collect the ids of the products you want to create shipment products for 
    @shipment.shipment_products.build([{:product_id=> ...},{:product_id=> ...}, ...]) 
end 

，这样你可以做类似

<%= form_for @shipment, :remote => true do |f|%> 
    ... 
    ... 
    <ul> 
    <%= f.fields_for :shipment_products do |sp_f| %> 
     <li> 
     <%= sp_f.text_field :qty_shipped %> 
     <%= sp_f.hidden_field :product_id %> 
     </li> 
    <% end %> 
    </ul> 
<% end %>