Rails 3-3个表之间关联的复杂表单

Question

我有三个相关的表格：

• 具有1限制的 (* - 1)
• 以及具有1特性的 (* - 1)

当我创建一个新的事实时，我需要在事实中加入新的形式，指示一个值来创建一个限制，并选择一个特性。我想知道使用复杂表单http://railscasts.com/episodes/73-complex-forms-part-1是否可以应用到我的问题上？

Answer 1

在MrYoshiji @MrYoshiji的建议之后，我能够用这种方法解决我的问题：

#事实模型

 class Fact < ActiveRecord::Base
 attr_accessible :description, :restriction
 belongs_to :restriction, :dependent => :destroy

 accepts_nested_attributes_for :restriction

 end

#约束模型

class Restriction < ActiveRecord::Base
attr_accessible :threshold, :feature
has_many :facts
belongs_to :feature

accepts_nested_attributes_for :feature  
end

#控制器

def new
    @fact = Fact.new
    @restriction = @fact.build_restriction
    @feature = @restriction.build_feature
    ...

def create
    @fact = Fact.new(fact_params)
    @feature = Feature.find(params[:feature][:id])
    @restriction = Restriction.new(:threshold => params[:fact][:threshold])
    @restriction.feature = @feature
    @restriction.save

    @fact.restriction = @restriction
    @fact.save
    ...

#事实视图

 <%= form_for(@fact) do |f| %>
 ...
     <%= fields_for "fact",@fact.restriction do |restr_form| %>
     ...
         <%= fields_for "fact",@fact.restriction.feature do |feat_form| %>
         ...

任何疑问法官都会问。

Answer 2

我认为你可以这样做：

# Fact model
accepts_nested_attributes_for :restriction
# Restriction model
accepts_nested_attributes_for :feature

# controller
@fact = Fact.new
@restriction = @fact.restriction.new
@feature = @restriction.feature.new

# view
form_for @fact do |fact_fields|
  # ...
  fields_for @restriction do |restriction_fields|
    # ...
    fields_for @feature do |feature_fields|
      # ...
    end
  end
end

您应该得到这样的参数：

{ 
  'fact' => {
     'some_stuff' => 'some_values',

     'restriction_attributes' => {
       'some_other_stuff' => 'some_other_values',

       'feature_attributes' => {
         'stuff' => 'values'
       }
     }
  }
}