带有check_box循环的Rails嵌套属性 [英] Rails Nested attributes with check_box loop

问题描述

所以我有一个类别模型

class Category < ActiveRecord::Base
has_many :provider_categories
has_many :providers, :through => :provider_categories
end

和提供者模型

class Provider < ActiveRecord::Base
has_many :provider_categories
has_many :categories, :through => :provider_categories

accepts_nested_attributes_for :provider_categories, :allow_destroy => true
end

这是我的provider_category模型

here is my provider_category model

class ProviderCategory < ActiveRecord::Base
belongs_to :provider
belongs_to :category
end

我正在尝试创建一个嵌套表单，以将类别包括在提供者表单中

I'm trying to create a nested form to include the categories into the provider form

= form_for @provider do |f|
  ...
  [e-mail]_index do |category,index|
    =f.fields_for :provider_category, category do |pl|
      =pl.check_box :category_id
      =pl.label category.name
      =pl.hidden_field :provider_id, value: @provider.id

当我加载得到的页面时，复选框不配合

The checkbox is not cooperating when I load the page I get

undefined method `category_id' for #<Category:0x0000010184ff60>

如果我将:category_id更改为id，那么它可以工作，但是html outpuy看起来像这样

if I change the :category_id to id it works but the html outpuy looks like this

<input name="provider[provider_category][id]" type="hidden" value="0"><input checked="checked" id="provider_provider_category_id" name="provider[provider_category][id]" type="checkbox" value="1">
<label for="provider_provider_category_Acupuncture">Acupuncture</label>
<input id="provider_provider_category_provider_id" name="provider[provider_category][provider_id]" type="hidden" value="1">

我最终使用了check_box_tag

I ended up using check_box_tag

[e-mail]_index do |category|
  =f.fields_for :provider_category, category do |pl|
    .li
      =check_box_tag "provider[provider_category][category_id]", category.id
      =pl.label category.name
      =pl.hidden_field :provider_id, value: @provider.id

现在html输出似乎是正确的，但是没有保存.当我选择多个项目时，这是保存中的哈希值

Now the html output seems to be correct but it's not saving it. When I select multiple items this is the hash from saving

"provider"=>{"name"=>"Mr. Awesome", "phone"=>"999-999-9999", "email"=>"[e-mail]", "address"=>"awesome land", "provider_category"=>{"category_id"=>"3", "provider_id"=>"1"}}, "commit"=>"Save", "id"=>"1"}

我确实选择了3个选项，但仅将最后一个添加到哈希中

I did select 3 options but only the last one was added to the hash

我还在提供者控制器的强大参数中添加了提供者类别

I also added the provider categories in the strong params of provider controller

params.require(:provider).permit(..., :provider_categories => [:category_id, :provider_id])

非常感谢您的帮助

推荐答案

根据模型定义，ProviderCategory具有属性category_id和provider_id.您收到以下错误消息:

AS per your model definitions, ProviderCategory has attributes category_id and provider_id. You are getting error as:

undefined method `category_id' for #<Category:0x0000010184ff60>

因为没有传递ProviderCategory的实例，而是传递了Category类的实例.注意category被传入

because instead of passing instance of ProviderCategory, you have passed an instance of Category class. Notice category being passed in

=f.fields_for :provider_category, category do |pl|

，并且由于模型Category中没有名为category_id的属性，因此会收到错误消息.

and as there is no attribute named category_id in model Category you receive the error.

要解决该问题，只需更新视图中的fields_for方法调用，如下所示:

To resolve that, just update the fields_for method call in your view as below:

=f.fields_for :provider_categories, category.provider_categories.build do |pl|

更新

此外，您还必须更新ProvidersController的强参数，以便将provider_categories的记录正确保存在数据库中:

Also, you would have to update the strong params of ProvidersController so that records for provider_categories are saved correctly in database:

params.require(:provider).permit(..., :provider_categories_attributes => [:category_id, :provider_id])

使用provider_categories_attributes而不是provider_categories

更新2

OP还有另一个问题，因为未经检查的category_id传递了值0，并且在provider_categories中创建了错误的记录，该记录的category_id设置为0.

OP had another problem, for the unchecked category_id, value 0 was being passed and incorrect records with category_id set as 0 were getting created in provider_categories.

建议通过将reject_if选项传递给Provider模型中的accepts_nested_attributes_for方法调用来拒绝这些记录，如下所示:

Suggested to reject those records by passing reject_if option to accepts_nested_attributes_for method call in Provider model as below:

class Provider < ActiveRecord::Base
  has_many :provider_categories
  has_many :categories, :through => :provider_categories
  accepts_nested_attributes_for :provider_categories, :allow_destroy => true, reject_if: proc { |attributes| attributes['category_id'] == "0" }
end  

复选框未传递所检查类别的ID，建议如下更新复选框代码:

Checkbox was not passing the id's of checked categories, suggested to update the checkbox code as below:

=pl.check_box :category_id, {}, category.id, 0

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