从另一个型号下拉菜单 [英] Drop down menu with value from another model

问题描述

我有产品属于系列。一个集合只是一个名字。产品有一个collection_id。

在我的_form视图中，用于创建和版本的产品，我想要一个带有所有集合名称的下拉菜单。

问题，似乎没有关联form.for的选择方法，我正在尝试使用：

select（method，choices，options = {}，
html_options = {}）

从文档，但我不明白。我必须写一个方法来创建一个表单？有什么选择和2个选项？两个参数应该足以填充<选项>
标签。

如何使用下拉式选单让我通过收藏名称将产品分配给我的产品？

解决方案

您可以使用集合选择，首先确保您的模型正确设置：

  class Product 
 belongs_to：collection 
 end 
 
 class Collection 
 has_many：products 
 end 
  

然后将集合选择添加到您的视图：

 <％= collection_select（：product，：collection_id，Collection.all，：id，：name）％> 
  

您还可以阅读文档 here 。

I have products belonging to collections. A collection is just a name. Products have a collection_id.

In my _form view that is used for creation and edition of products, i'd like to have a drop down menu with the name of all collection.

Problem, it seems there is no select method affiliated to form.for and i am trying to use :

select(method, choices, options = {}, html_options = {})

from the doc but i do not understand it. I must write a methode to create a form? What are the choices, and the 2 options? Two parameters should be enough to populate an < option> tag.

How can I have a drop down menu alowing me to assign a collection through collection name to my product?

解决方案

You can use a collection select, first make sure your models are properly setup:

class Product
  belongs_to :collection
end

class Collection
  has_many :products
end

Then add the collection select to your view:

<%= collection_select(:product, :collection_id, Collection.all, :id, :name) %>

You can also read up on the documentation here.

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