ruby-on-rails - Rails fields_for 表单未显示

Question

products_controller.rb

def new
  @product = Product.new
  @product.build_discount
end

product.rb

has_many :discounts, :dependent => :destroy
accepts_nested_attributes_for :discounts
attr_accessible :discounts_attributes

折扣.rb

belongs_to :product

_edit_product.html.erb

<%= form_for(product, :html => { :multipart => true  }, :remote => true) do |f| %>
    // STUFF
    <%= f.fields_for :discounts do |discount_form| %>
       //does not show up
    <% end %>
<% end %>

fields_for block 中的内容不显示。但是，如果我将 has_many :discounts 更改为 has_many :discount，则会显示该表单(尝试提交时出现质量分配错误)。

关于为什么在 fields_for block 中不呈现表单以及为什么在我更改复数形式时它呈现的任何想法？

Answer 1

您想要许多折扣还是一个折扣？

@product.build_discount 用于 has_one 关联，但您的其余代码用于 has_many

如果您想要许多折扣，则将其更改为@product.discounts.build

否则，如果您只想要一个折扣，请更改以下内容:

f.fields_for :discount do |discount_form| 和 accepts_nested_attributes_for :discount 为单数。

@products.discounts.build 将不起作用，因为您无法从对象集合中获得关联。例如:

@products = Product.all
@discount = @products.discounts.build
# This won't work! You'll get an error

@product = Product.find(params[:id])
@discount = @product.discounts.build
# This will work, since you're running it on a single instance of Product