Ruby on Rails 中的多态性和形式 [英] Polymorphism and forms in Ruby on Rails
问题描述
我最近遇到了很多问题,但是感谢这个很棒的社区,我学到了很多东西.
I've been full of questions lately, but thanks to this awesome community, I'm learning a ton.
我之前获得了多态关联所需的所有帮助,现在我有一个关于使用多态模型处理表单的问题.例如,我有 Phoneable 和 User,所以当我创建表单来注册用户时,我希望能够为用户分配一些电话号码(即:手机、工作、家庭).
I got all the help I needed with polymorphic associations earlier and now I have a question about tackling forms with polymorphic models. For instance I have Phoneable and User, so when I create my form to register a user, I want to be able to assign a few phone numbers to the user (ie: cell, work, home).
class User < ActiveRecord::Base
has_many :phones, :as => :phoneable
end
class Phone < ActiveRecord::Base
belongs_to :phoneable, :polymorphic => true
end
class CreateUsers < ActiveRecord::Migration
t.column :name, :string
t.references :phoneable, :polymorphic => true
end
class CreatePhones < ActiveRecord::Migration
t.column :area_code, :integer
t.column :number, :integer
t.column :type, :string
t.references :phoneable, :polymorphic => true
end
现在,当我创建表单时,我感到很困惑.通常我会这样做:
Now when I create my form, I'm getting confused. Normally I would do the following:
- form_for :user, :html => {:multipart => true} do |form|
%fieldset
%label{:for => "name"} Name:
= form.text_field :name
##now how do I go about adding a phone number?
##typically I'd do this:
##%label{:for => "phone"} Phone:
##= form.text_field :phone
使用多态,我是否会以同样的方式处理,但使用 fields_for?
Using polymorphism, would I just approach the same way, but use fields_for?
- user_form.fields_for :phone do |phone| %>
%label{for => "area_code"} Area Code:
= phone.text_field :area_code
%label{for => "number"} Number:
= phone.text_field :number
在这种情况下,这是正确的方法吗?
Is this the correct approach in this instance?
推荐答案
在我们进一步讨论之前,我确实注意到了一个问题 - 你不需要 t.references
和 has_many
关联的一侧.所以你在 create_user
模型中不需要它.它的作用是创建 phonable_id
和 phoneable_type
列,您只需要在多态模型中使用它.
Before we go further, I did notice one issue - you do not need the t.references
with the has_many
side of the association. So you do not need it in the create_user
model. What that does is it creates the phonable_id
and the phoneable_type
columns, you only need that in the polymorphic model.
使用 fields_for
方法,您正朝着正确的方向前进.但是为了让它工作,你需要告诉模型如何处理这些字段.您可以使用 accepts_nested_attributes_for
类方法来做到这一点.
You are heading down the correct path with the fields_for
approach. But in order to get that working, you need to tell the model how to handle those fields. You do that with the accepts_nested_attributes_for
class method.
class User < ActiveRecord::Base
has_many :phones, :as => :phoneable
accepts_nested_attributes_for :phones
end
还有一件小事,您需要让 fields_for
指向关联的确切名称
and one minor thing, you will need to have the fields_for
point to the exact name of the association
- form_for @user do |user_form|
- user_form.fields_for :phones do |phone|
代替
- form_for @user do |user_form|
- user_form.fields_for :phone do |phone|
并确保删除您的流浪 %>
erb 标记 :)
and make sure you remove your stray %>
erb tag :)
更多关于 accepts_nested_attributes_for
:http://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html
我希望这会有所帮助!
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