如何使用accepts_nested_attributes_for在Rails3中创建嵌套对象？

Question

我无法弄清楚如何设置一个创建新的表单,Study同时还创建相关的StudySubject和Facility.的user_id,facility_id并且study_subject_id必须是可用于创建Study对象,你可以在数据库中关系模型看.

这是迁移的studies.其他表不包含外键.

def self.up
 create_table :studies do |t|
  t.references :user
  t.references :facility
  t.references :subject
  t.date "from"
  t.date "till"
  t.timestamps
 end
 add_index :studies, ["user_id", "facility_id", "subject_id"], :unique => true
end

模型定义了以下关联.

# user.rb
has_many :studies

# subject.rb
has_many :studies

# facility.rb
has_many :studies

# study
belongs_to :user
belongs_to :subject
belongs_to :facility

问题

1)has_many和belongs_to定义是否正确？
2)如何study使用accepts_nested_attributes_for创建一个？
3)研究应该只属于一个用户.我是否需要将其添加user_id到每个其他对象中以存储关联？

自从2周的广泛学习以来,我对Rails全新.对不起,也许是一个愚蠢的问题.

Answer 1

是的。有用。一位好朋友提供了帮助。这就是我们设置的。
请注意我同时重命名StudySubject为。Subject

该模型 study.rb

belongs_to :student, :class_name => "User", :foreign_key => "user_id"  
belongs_to :subject  
belongs_to :university, :class_name => "Facility", :foreign_key => "facility_id"  

accepts_nested_attributes_for :subject, :university

控制器 studies_controller.rb

def new
  @study = Study.new
  @study.subject = Subject.new
  @study.university = Facility.new
end

def create
  @study = Study.new(params[:study])
  @study.student = current_user

  if @study.save
    flash[:notice] = "Successfully created study."
    redirect_to(:action => 'index')
  else
    render('new')
  end
end

我使用devise进行身份验证，使用cancan进行授权。这就是current_user控制器中可用的原因。

新的研究观点 new.html.erb

<%= form_for @study, :url => { :action => "create" } do |f| %>

  <table summary="Study form fields">

    <%= render :partial => "shared/study_form_fields", :locals =>  { :f => f } %>

    <%= f.fields_for :subject do |builder| %>
      <%= render :partial => "shared/subject_form_fields", :locals =>  { :f => builder } %>
    <% end %>

    <%= f.fields_for :university do |builder| %>
      <%= render :partial => "shared/facility_form_fields", :locals =>  { :f => builder } %>
    <% end %>

  </table>

  <p><%= f.submit "Submit" %></p>

<% end %>

我希望这能为您节省一些时间。我花了很多时间来了解如何设置。