Ruby on Rails：如何在特定条件下验证嵌套属性？

Question

提问by Tintin81

I have these models:

我有这些模型：

class Organisation < ActiveRecord::Base

  has_many    :people
  has_one     :address, :as         => :addressable,
                        :dependent  => :destroy
  accepts_nested_attributes_for :address, :allow_destroy => true

end

class Person < ActiveRecord::Base

  attr_accessible :first_name, :last_name, :email, :organisation_id, :address_attributes

  belongs_to  :user
  belongs_to  :organisation
  has_one     :address, :as         => :addressable,
                        :dependent  => :destroy
  accepts_nested_attributes_for :address, :allow_destroy => true

  # These two methods seem to have no effect at all!
  validates_presence_of :organisation,  :unless => "address.present?"
  validates_associated  :address,       :unless => "organisation.present?"

end

class Address < ActiveRecord::Base

  belongs_to :addressable, :polymorphic => true

  validates_presence_of :line1, :line2, :city, :zip

end

...and these views:

...以及这些观点：

_fields.html.erb:

_fields.html.erb：

<%= render 'shared/error_messages', :object => f.object %>
<fieldset>
<div class="left">
    <%= f.label :first_name %><br/>
    <%= f.text_field :first_name %>
</div>
<div>
    <%= f.label :last_name %><br/>
    <%= f.text_field :last_name %>
</div>
<div>
    <%= f.label :email %><br/>
    <%= f.text_field :email %>
</div>
<div>
    <%= f.label :organisation_id %><br/>
    <%= f.select(:organisation_id, current_user.organisation_names, {:include_blank => "--- None ---"}, :id => 'organisation_select') %>
</div>
</fieldset>

<%= f.fields_for :address do |address| %>
  <%= render 'shared/address', :f => address %>
<% end %>

_address.html.erb:

_address.html.erb：

<fieldset id="address_fields">
<div>
    <%= f.label :line1 %>
    <%= f.text_field :line1 %>
</div>
<div>
    <%= f.label :line2 %>
    <%= f.text_field :line2 %>
</div>
<div>
    <%= f.label :zip %>
    <%= f.text_field :zip %>
</div>  
<div>
    <%= f.label :city %>
    <%= f.text_field :city %>
</div>  
</fieldset>

people_controller.rb:

def new
  puts params.inspect
  @person = Person.new(:organisation_id => params[:organisation_id])
  @person.build_address
  @title = "New person"
end

{"action"=>"new", "controller"=>"people"}

def edit
  puts params.inspect
  @title = @person.name
end

{"action"=>"edit", "id"=>"69", "controller"=>"people"}

def create
  puts params.inspect
  if params[:organisation_id]
    @person = current_user.organisations.build_person(params[:person])
  else
    @person = current_user.people.build(params[:person])
  end
  if @person.save
    flash[:success] = "Person created."
    redirect_to people_path
  else
    render :action => "new"
  end
end

{"commit"=>"Create", "action"=>"create", "person"=>{"last_name"=>"Doe", "organisation_id"=>"9", "email"=>"[email protected]", "first_name"=>"John", "address_attributes"=>{"city"=>"Chicago", "zip"=>"12345", "line2"=>"Apt 1", "line1"=>"1 Main Street"}}, "authenticity_token"=>"Jp3XVLbA3X1SOigPezYFfEol0FGjcMHRTy6jQeM1OuI=", "controller"=>"people", "utf8"=>"?"}

Inside my Personmodel I need to make sure that only if a person's organisation_idis blank, that person's address fields have to be present.

在我的Person模型中，我需要确保只有当一个organisation_id人的地址为空时，该人的地址字段才必须存在。

I tried something like this:

我试过这样的事情：

validates :address, :presence => true, :if => "organisation_id.blank?"

But it's not working.

但它不起作用。

How can this be done?

如何才能做到这一点？

Thanks for any help.

谢谢你的帮助。

Answer 1

回答by Matt Dressel

First of all, I want to be sure that you mean blank?rather than present?. Typically, I see this:

首先，我想确定您的意思是blank?而不是present?。通常，我看到这个：

validate :address, :presence_of => true, :if => 'organisation.present?'

Meaning, you only want to validate address if organisation is also present.

意思是，如果组织也存在，您只想验证地址。

Regarding, :accepts_nested_attributes_for, are you using this feature by passing in nested form attributes, or some such thing? I just want to make sure you absolutely need to use this functionality. If you are not actually dealing with nested form attributes, you can implement cascading validation using:

关于，:accepts_nested_attributes_for您是通过传递嵌套表单属性还是某些类似的东西来使用此功能？我只是想确保您绝对需要使用此功能。如果您实际上没有处理嵌套的表单属性，则可以使用以下方法实现级联验证：

validates_associated :address

If you do need to use :accepts_nested_attributes, be sure to check out the :reject_ifparameter. Basically, you can reject adding an attribute (and it's descendants) altogether if certain conditions apply:

如果确实需要使用:accepts_nested_attributes，请务必检查:reject_if参数。基本上，如果某些条件适用，您可以完全拒绝添加属性（及其后代）：

accepts_nested_attributes_for :address, :allow_destroy => true, :reject_if => :no_organisation

def no_organisation(attributes)
  attributes[:organisation_id].blank?
end

Now, if none of the above apply, let's take a look at your syntax:

现在，如果以上都不适用，让我们来看看你的语法：

It should work, :if/:unlesstake symbols, strings and procs. You don't need to point to the foreign_key, but can simplify by pointing to:

它应该可以工作，:if/:unless采用符号、字符串和 procs。您不需要指向foreign_key，但可以通过指向来简化：

:if => "organisation.blank?"

You have other validations in the Address model, correct? Is Address being validated when you don't want it to? Or is Address not being validated? I can help you test it out in the console if you can give me some additional details.

您在 Address 模型中有其他验证，对吗？当您不希望地址被验证时，它会被验证吗？或者地址没有被验证？如果你能给我一些额外的细节，我可以帮你在控制台中测试它。

To make things easier for myself re: mass-assignment, I changed the rails config: config.active_record.whitelist_attributes = false
I created a gist for you to follow along
I have a sample project as well. Let me know if you are interested.
Basic points:
Added the following to Person to ensure that either Org or Address are valid:
validates_presence_of :organisation, :unless => "address.present?"validates_associated :address, :unless => "organisation.present?"
Added validation to Address to trigger errors when Org is not present: validates_presence_of :line1, :line2, :city, :zip
I was able to produce the requirements you are seeking. Please look at the gist I createdwhere I have a full console test plan.

为了让我自己更轻松：mas-assignment，我更改了 rails 配置： config.active_record.whitelist_attributes = false
我创建了一个要点供您遵循
我也有一个示例项目。如果您有兴趣，请告诉我。
基本要点：
将以下内容添加到 Person 以确保 Org 或 Address 有效：
validates_presence_of :organisation, :unless => "address.present?"validates_associated :address, :unless => "organisation.present?"
添加了对 Address 的验证以在 Org 不存在时触发错误： validates_presence_of :line1, :line2, :city, :zip
我能够产生您正在寻求的要求。请查看我创建的要点，其中有完整的控制台测试计划。

I added a controller file to the previous gist.

我在之前的 gist 中添加了一个控制器文件。

Overview:

概述：

All you should need to create the person is: @person = current_user.people.build(params[:person])
:organisation_id will always be found off of the :person param node, like so: params[:person][:organisation_id]So you're if will never be true.

创建此人所需的全部内容是： @person = current_user.people.build(params[:person])
:organisation_id 总是会从 :person 参数节点中找到，就像这样： params[:person][:organisation_id]所以你如果永远不会是真的。

I updated the gist with the necessary changes to the controller, the modeland the form.

我更新了要点，对控制器、模型和表单进行了必要的更改。

Overview:

概述：

You need to cleanup your controller. You are using accepts_nested_attribute, so in the :create, you only care about params[:person]. Additionally, in the render :new, you need to setup any instance variables that the partial will use. This does NOTgo back through the :newaction. The :newand :editactions also need to be simplified.
Your Person model needs to use the :reject_ifargument because the Address fields are coming back to the :create action as :address_attributes => {:line1 => '', :line2 => '', etc}. you only want to create the association if any have values. Then your validates_presence_offor :organisationwill work just fine.
Your form needs to pass the organisation id to the controller, rather than the organisation names
It's all in the gist

您需要清理控制器。您正在使用accepts_nested_attribute，因此在 :create 中，您只关心params[:person]. 此外，在中render :new，您需要设置部分将使用的任何实例变量。但这不是通过返回:new的动作。该:new和:edit行动也必须简化。
您的 Person 模型需要使用该:reject_if参数，因为 Address 字段将返回到 :create 操作 as :address_attributes => {:line1 => '', :line2 => '', etc}。如果有任何值，您只想创建关联。那么你的validates_presence_offor:organisation将工作得很好。
您的表单需要将组织 ID 传递给控制器，而不是组织名称
一切都在要点中

Should be the final gist.

应该是最后的要点。

Overview:

概述：

Add the following to your edit action right after building the @person:
@person.build_address if @person.address.nil? This ensure that you have the address inputs, even if the @person.address does not exist. It doesn't exist, because of the :reject_if condition on accepts_nested_attributes
I DRYed up the :reject_if as follows. It's a little hacky, but has some utility:
```
accepts_nested_attributes_for :address, :allow_destroy => true, :reject_if => :attributes_blank?

def attributes_blank?(attrs)  
  attrs.except('id').values.all?(&:blank?)  
end  
```
a. attrs-> the result of params[:person][:address]
b. .except('id')-> return all key-values except for 'id'
c. .values-> return all values from a hash as an array
d. .all?-> do all elements in the array satisfy the following check
e. &:blank-> ruby shorthand for a block, like this: all?{ |v| v.blank? }

在构建@person 后立即将以下内容添加到您的编辑操作中：
@person.build_address 如果@person.address.nil？这确保您有地址输入，即使 @person.address 不存在。它不存在，因为 accepts_nested_attributes 上的 :reject_if 条件
我干了 :reject_if 如下。它有点hacky，但有一些实用性：
```
accepts_nested_attributes_for :address, :allow_destroy => true, :reject_if => :attributes_blank?

def attributes_blank?(attrs)  
  attrs.except('id').values.all?(&:blank?)  
end  
```
一种。attrs-> params[:person][:address] 的结果
b. .except('id')-> 返回除 'id' 之外的所有键值
c. .values-> 将散列中的所有值作为数组返回
d. .all?-> 数组中的所有元素是否满足以下检查
e. &:blank-> ruby 块的简写，如下所示：all?{ |v| v.blank? }

Answer 2

回答by varatis

Are you sure you didn't mean:

你确定你不是说：

validates :address, :presence => true, :if => organisation_id.nil?

Answer 3

回答by Matt

A more simple approach might be to add a custom validator. It's super easy, and you don't have to stumble on syntax or try to figure out why Rails' magic isn't working.

更简单的方法可能是添加自定义验证器。这非常容易，而且您不必偶然发现语法或试图弄清楚为什么 Rails 的魔法不起作用。

Inside my Person model I need to make sure that only if a person's organisation_id is blank, that person's address fields have to be present.

在我的 Person 模型中，我需要确保只有当一个人的 organization_id 为空时，该人的地址字段才必须存在。

class Person < ActiveRecord::Base
  ...
  validate :address_if_organisation_id_is_present

  private

  def address_if_organisation_id_is_present
    return true unless organisation_id
    errors.add(:address, "cannot be blank") unless address
  end
end

Adding to a model's errors will prevent it from saving. Note: you may wish to use address.blank?or address.empty?as discussed in other answers, but you can define this for the behavior you'd like.

添加到模型的错误将阻止它保存。注意：您可能希望使用address.blank?或address.empty?在其他答案中讨论，但您可以为您想要的行为定义它。

Ruby on Rails：如何在特定条件下验证嵌套属性？

提问by Tintin81

回答by Matt Dressel

回答by varatis

回答by Matt

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Ruby on Rails：如何在特定条件下验证嵌套属性？

提问by Tintin81

回答by Matt Dressel

回答by varatis

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