Question

关注railscast＃196但使用Rails 4 - 我在尝试从问题父模型中删除答案时遇到了问题。

未经许可的参数：_destroy

_answer_fields.html.erb

<fieldset>                                                                                                                                                                                                  
    <%= f.text_field :response %>                                                                                                                                                                       
    <%= f.hidden_field :_destroy %>                                                                                                                                                                                                                                                                                                                                                                                 
    <%= link_to "remove" , "#", class: "remove_fields" %>                                                                                                                                               
</fieldset>

question.rb

accepts_nested_attributes_for :questions, :allow_destroy => true

surveys_controller.rb

def survey_params                                                                                                                                                                                       
  params.require(:survey).permit(:name, :questions_attributes => [:id, :content, :answers_attributes => [:id, :response]])                                                                              
end

我在单击时删除了表单中的字段，但该记录尚未删除。

谢谢

编辑：JS设置隐藏变量

 jQuery ->                                                                                                                                                                                                   
        $(document).on 'click' , ".remove_fields" , (event) ->                                                                                                                                              
                $(this).prev('input[type=hidden]').val('1')                                                                                                                                                 
                $(this).closest('fieldset').hide()                                                                                                                                                          
                event.preventDefault()

Answer 1

@Hitham S. AlQadheeb可能是对的 - 检查你的模型是否正确......

survey.rb

class Survey < ActiveRecord::Base
  has_many :questions, :dependent => :destroy
  accepts_nested_attributes_for :questions
end

和 question.rb

class Question < ActiveRecord::Base
  belongs_to :survey
  has_many :answers, :dependent => :destroy
  accepts_nested_attributes_for :answers, :reject_if => lambda { |a| a[:content].blank? }, :allow_destroy => true
end

然而，Unpermitted parameters: _destroy错误实际上应该指的是您的控制器对强参数的实现：survey_params。您需要告诉rails您的表单将通过:_destroy字段。试试这个：

def survey_params                                                                                                                                                                                       
  params.require(:survey).permit(:name, :questions_attributes => [:id, :content, :_destroy, :answers_attributes => [:id, :response, :_destroy]])                                                                              
end
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Answer 2

应该是

question.rb

belongs_to :survey 
has_many :answers, : dependent => :destroy
accepts_nested_attributes_for :answers, :allow_destroy => true

再看一遍http://railscasts.com/episodes/196-nested-model-form-part-1

删除嵌套属性时未允许的属性_destroy

2 个答案: