rails4集合通过关联和嵌套模型表单使用hasmany进行选择

我有一个rails4应用程序。目前,我的收藏选择仅在我只选择一个选项时有效。下面是我的工作代码。我只有产品形式。行业模型填充了 seeds.rb .IndustryProduct仅用于连接其他2个型号。

我想知道我必须在代码中更改什么才能选择更多。

我看到了一些与 multiple: true 类似选项( https://www.youtube.com/watch?v=ZNrNGTe2Zqk 10:20),但在这种情况下,UI有点丑+无法用任何示例代码实现。有没有其他解决方案,比如让多个框选择一个选项,而不是一个框选择多个选项?

模型:

class Product < ActiveRecord::Base
  belongs_to :user
  has_many :industry_products
  has_many :industries, through: :industry_products
  has_many :product_features

  accepts_nested_attributes_for :industry_products, allow_destroy: true
  accepts_nested_attributes_for :product_features

  validates_associated :industry_products
  validates_associated :product_features
end

class Industry < ActiveRecord::Base
  has_many :industry_products
  has_many :products, through: :industry_products

  accepts_nested_attributes_for :industry_products
end

class IndustryProduct < ActiveRecord::Base
  belongs_to :product
  belongs_to :industry
end

_表单.html erb

<%= form_for @product do |f| %>
  <%= render 'layouts/error_messages', object: f.object %>
  ......
  <%= f.fields_for :industry_products do |p| %>
    <%= p.collection_select :industry_id, Industry.all, :id, :name %>
  <% end %>
  <%= f.fields_for :product_features do |p| %>
    <%= p.text_field :feature, placeholder: "add a feature", class: "form-control" %>
  <% end %>
  <%= f.submit class: "btn btn-primary" %>
<% end %>

产品控制器

def new
  @product = Product.new
  @product.industry_products.build
  @product.product_features.build
end

def create
  @product = current_user.products.new(product_params)
  if @product.save
    redirect_to @product
  else
    render action: :new
  end
end
......
def product_params
  params.require(:product).permit(....., industry_products_attributes: [:id, :industry_id, :_destroy], industries_attributes: [:id, :name], product_features_attributes: [:feature])
end