Rails中嵌套表单的解决

最新推荐文章于 2019-03-15 17:29:04 发布

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最新推荐文章于 2019-03-15 17:29:04 发布

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本文详细介绍了Rails中嵌套表单的实现方法，包括如何配置模型接受嵌套属性、控制器中的参数允许策略以及视图层如何构建嵌套表单。通过具体案例展示了嵌套表单在一对多和一对一关系中的应用。

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什么是嵌套表单呢？举个简单的例子吧，比如你有两个表，一个User表，另一个Account表，他们是一对一的关系（也可以一对多等）。现在需要提交一个表单的时候同时提交User，Account对应的字段数据。在Rails中有一种简单的方法解决，分别使用了这些方法

accepts_nested_attributes_for 
attr_accessible
fields_for

下面我们用代码进行说明一下。

class User < ActiveRecord::Base
   has_one :account 

   accepts_nested_attributes_for :account  #注意添加这两行
   attr_accessible  :account_attributes

end

class Account<ActiveRecord::Base
belongs_to :user

class UsersController < ApplicationController
  def new
    @user = User.new
    @user.account.build #不要遗漏
  end

 def create
     @user = User.new(params[:user])
     if @user.save
       ...         
     end
  end
end

users/new.html.erb:

 <% form_for @user do |f| %>
    <%= f.text_field :name %>
    <% f.fields_for :account do |pf| %> #注意这里
      <%= pf.text_field :age %>
    <% end %>
 <% end %>

这是一对一的情况，假设是一对多呢，如User has_many :accounts ; Account belongs_to :user这种情况下只要将对应的account改写成accounts，就ok了

一些深入参考：

http://robots.thoughtbot.com/post/52960938209/accepts-nested-attributes-for-with-has-many-through

http://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html

以上是Rails3中，如果在Rails4中使用了Using Strong Parameters ,参考这里

去掉model中的 attr_accessible :account_attributes ，在对应的controller中添加Strong Parameters的方法

http://www.railsexperiments.com/using-strong-parameters-with-nested-forms/

实例1：

coupon.rb中：

accepts_nested_attributes_for :cdkey, allow_destroy: true

作用是添加一对一cdkey表单的嵌套

_form.html.erb中：

div class="ui form">
<%= form_for [:manage, @coupon], html: {multipart: true} do |f| %>

<div class="fields">
<div class="field">
<%= f.label :coupon_type %>
<%= f.select :coupon_type, Coupon::CouponType, {include_blank: "select coupon type"}, class: "ui dropdown" %>
</div>

<div class="field">
<%= f.label :total_count, "数量限制" %>
<%= f.text_field :total_count %>
</div>
</div>

<div class="ui segment">

<h4 class="ui header">CDKEY</h4>

<div class="fields">
<%= f.fields_for :cdkey do |c| %>
<div class="field">
<%= c.label :code, "cdkey 设置后可以输入该cdkey兑换优惠券" %>
<%= c.text_field :code %>
</div>

<div class="field">
<%= c.label :count, "该cdkey可以兑换的次数" %>
<%= c.text_field :count %>
</div>

<div class="field">
<%= c.label :start_at %>
<%= c.text_field :start_at, class: "datepicker" %>
</div>

<div class="field">
<%= c.label :end_at %>
<%= c.text_field :end_at, class: "datepicker" %>
</div>

<div class="field">
<label for="">Delete</label>
<div class="ui checkbox">
<%= c.check_box :_destroy, style: "display: hidden" %>
<%= label_tag "删除" %>
</div>
</div>
<% end %>
</div>

</div>

<div class="field">
<%= f.label :name %>
<%= f.text_field :name %>
</div>

<div class="field">
<%= f.label :description %>
<%= f.text_area :description, rows: 2 %>
</div>

<div class="fields">
<div class="field">
<%= f.label :start_time %>
<%= f.text_field :start_time, class: "datepicker" %>
</div>
<div class="field">
<%= f.label :end_time %>
<%= f.text_field :end_time, class: "datepicker" %>
</div>
</div>

<div class="fields">
<div class="field">
<%= f.label :active_days %>
<%= f.text_field :active_days %>
</div>
<div class="field">
<%= f.label :expiration_time %>
<%= f.text_field :expiration_time, class: "datepicker" %>
</div>
</div>

<div class="fields">
<div class="field">
<%= f.label :value %>
<%= f.text_field :value %>
</div>
<div class="field">
<%= f.label :status %>
<%= f.select :status, Coupon::STATUS, {}, class: "ui dropdown" %>
</div>
</div>

<div class="fields">
<div class="field">
<%= f.label :no_prefix %>
<%= f.text_field :no_prefix %>
</div>
</div>

<div class="ui segment">

<h4 class="ui header">Can use countries</h4>

<div class="ui grid">

<div class="ui wide column">
<div class="ui checkbox">
<%= check_box_tag "coupon[countries_limit][]", "all", @coupon.countries_limit.to_a.include?("all"), style: "display: hidden" %>
<%= label_tag "all" %>
</div>
</div>

<% SupportCountry.all.each do |sc| %>
<div class="ui wide column">
<div class="ui checkbox">
<%= check_box_tag "coupon[countries_limit][]", sc.iso_code, @coupon.countries_limit.to_a.include?(sc.iso_code), style: "display: hidden" %>
<%= label_tag sc.iso_code %>
</div>
</div>
<% end %>
</div>

</div>

<div class="field">
<button class="ui submit blue button" type="submit" name="action">
Submit
</button>
</div>

<% end %>
</div>

注意： <%= f.fields_for :cdkey do |c| %>
<div class="field">
<%= c.label :code, "cdkey 设置后可以输入该cdkey兑换优惠券" %>
<%= c.text_field :code %>
</div>

<div class="field">
<%= c.label :count, "该cdkey可以兑换的次数" %>
<%= c.text_field :count %>
</div>

<div class="field">
<%= c.label :start_at %>
<%= c.text_field :start_at, class: "datepicker" %>
</div>

<div class="field">
<%= c.label :end_at %>
<%= c.text_field :end_at, class: "datepicker" %>
</div>

<div class="field">
<label for="">Delete</label>
<div class="ui checkbox">
<%= c.check_box :_destroy, style: "display: hidden" %>
<%= label_tag "删除" %>
</div>
</div>
<% end %>

这一段为对嵌套表单的提交

coupon_controller.rb中：

def edit
@coupon = Coupon.find(params[:id])
if @coupon.cdkey.present?
@cdkey =@coupon.cdkey
else
@cdkey = @coupon.build_cdkey
end
end

def update
@coupon = Coupon.find(params[:id])
if @coupon.update(coupon_params)
redirect_to manage_coupons_path
end
end

private
def coupon_params
params.require(:coupon).permit(
:name, :coupon_type, :value, :description, :start_time, :end_time,
:active_days, :expiration_time, :status, :no_prefix, :total_count, cdkey_attributes: [:id, :code, :start_at, :end_at, :count, :_destroy],
countries_limit: []
)
end

注意：edit中的 @cdkey = @coupon.build_cdkey这句和coupon_params健壮参数中 cdkey_attributes: [:id, :code, :start_at, :end_at, :count, :_destroy],这句