ruby-on-rails - 无法修改关联 'Survey#answers'，因为它经历了多个其他关联

Question

我有一个处理调查及其答案的嵌套表单。但是当我加载表单时出现一个奇怪的错误:

ActiveRecord::HasManyThroughNestedAssociationsAreReadonly

有任何想法吗？我不确定我应该如何修复这些关联。

<%= form_for @survey do |f| %>

...
<%= f.fields_for :answers do |builder| %>
  <%= builder.text_field :content, :class=>"form-control" %>
<% end %>

...

<% end %>

调查#new

  def new
    @survey = Survey.new
    @template = Template.find(params[:template_id])
    @patient = Patient.find(params[:patient_id])
    @survey.answers.build
  end

调查.rb

class Survey < ActiveRecord::Base
      belongs_to :template
      has_many :questions, :through=> :template
      has_many :answers, :through=> :questions
      accepts_nested_attributes_for :answers
    end

模板文件

class Template < ActiveRecord::Base
    belongs_to :survey
    has_many :questions
end

问题.rb

class Question < ActiveRecord::Base
  belongs_to :template
  has_many :answers
end

答案.rb

class Answer < ActiveRecord::Base
  belongs_to :question
end

Answer 1

您错过了线路 has_many :templates在 Survey.rb 中。
您还必须指定 :templates (型号名称的复数)在
相同的文件:
has_many :questions, :through=> :templates
所以最终的变体是:

class Survey < ActiveRecord::Base
      has_many :templates
      has_many :questions, :through=> :templates
      has_many :answers, :through=> :questions
      accepts_nested_attributes_for :answers
    end

也作为你的模特 survey和 answer是关联的，您不需要在 Controller 中获取模板:

def new
    @survey = Survey.new
    @patient = Patient.find(params[:patient_id])
    @survey.answers.build
end