我有一堆“小孩”对象已经保存,我想创建一个父对象,通过“亲戚”模式链接到孩子.
这个对象给了我一对多,通过亲戚.
要明确:用户访问“父母”页面,点击创建父母,并提供一个表格,让他们命名父母,并加起来这个父母的四个孩子(通过创建“亲戚”),这些“关系” “也被命名 – 这是重要的一部分.所以,我可以命名关系“步子”或“儿子”.
以下是我到目前为止的代码:
- class Kid < ActiveRecord::Base
- has_many :relatives
- has_many :parents,through: :relatives
- end
- class Parent < ActiveRecord::Base
- has_many :relatives
- has_many :kids,through: :relatives
- accepts_nested_attributes_for :relatives,:reject_if => lambda { |a| a[:content].blank? },:allow_destroy => true
- end
- class Relative < ActiveRecord::Base
- belongs_to :parent
- belongs_to :kid
- end
- class ParentsController < ApplicationController
- before_action :set_parent,only: [:show,:edit,:update,:destroy]
- before_action :lookup_kids,only: [:new,:edit]
- # GET /parents
- # GET /parents.json
- def index
- @parents = Parent.all
- end
- # GET /parents/1
- # GET /parents/1.json
- def show
- end
- # GET /parents/new
- def new
- @parent = Parent.new
- 4.times { @parent.relatives.build }
- end
- # GET /parents/1/edit
- def edit
- end
- # POST /parents
- # POST /parents.json
- def create
- @parent = Parent.new(parent_params)
- parent_params[:relatives_attributes].each do |k,r|
- @parent.relatives.build(r.except(:_destroy))
- end
- respond_to do |format|
- if @parent.save
- format.html { redirect_to @parent,notice: 'Parent was successfully created.' }
- format.json { render :show,status: :created,location: @parent }
- else
- format.html { render :new }
- format.json { render json: @parent.errors,status: :unprocessable_entity }
- end
- end
- end
- # cut for brevity.
- private
- # Use callbacks to share common setup or constraints between actions.
- def set_parent
- @parent = Parent.find(params[:id])
- end
- def parent_params
- params.require(:parent).permit(:name,relatives_attributes: [:parent_id,:kid_id,:relationship,:_destroy])
- end
- def lookup_kids
- @kids = Kid.all #for this nursery.
- end
- end
- <%= form_for(@parent) do |f| %>
- <% if @parent.errors.any? %>
- <div id="error_explanation">
- <h2><%= pluralize(@parent.errors.count,"error") %> prohibited this parent from being saved:</h2>
- <ul>
- <% @parent.errors.full_messages.each do |message| %>
- <li><%= message %></li>
- <% end %>
- </ul>
- </div>
- <% end %>
- <div class="field">
- <%= f.label :name %><br>
- <%= f.text_field :name %>
- </div>
- <h4>Kids:</h4>
- <%= f.fields_for :relatives do |r| %>
- <%= r.label :kid %>
- <%= r.collection_select :kid_id,@kids,:id,:name,include_blank: true%>
- <%= r.label :relationship %>
- <%= r.text_field :relationship %>
- <%= r.check_Box :_destroy %>
- <%= r.label :_destroy,"Remove" %>
- <br/>
- <% end %>
- <div class="actions">
- <%= f.submit %>
- </div>
- <% end %>
- ActiveRecord::Schema.define(version: 20151030113634) do
- create_table "kids",force: :cascade do |t|
- t.string "name"
- t.datetime "created_at",null: false
- t.datetime "updated_at",null: false
- end
- create_table "parents",null: false
- end
- create_table "relatives",force: :cascade do |t|
- t.string "relationship"
- t.integer "parent_id"
- t.integer "kid_id"
- t.datetime "created_at",null: false
- end
- add_index "relatives",["kid_id"],name: "index_relatives_on_kid_id"
- add_index "relatives",["parent_id"],name: "index_relatives_on_parent_id"
- end
当我在父母控制器中“创建”时,我可以看到正确的参数正在通过,但关系记录没有被保存.这不会自动发生吗?
我尝试循环遍历:relatives_attributes,但似乎不适用于“build”.
我怎样才能让“亲戚”记录得到保存?
编辑:添加参数发布:
- parent"=>{
- "name"=>"Dad","relatives_attributes"=>{
- "0"=>{"kid_id"=>"2","relationship"=>"Son","_destroy"=>"0"},"1"=>{"kid_id"=>"","relationship"=>"","2"=>{"kid_id"=>"","3"=>{"kid_id"=>"","_destroy"=>"0"}}}
编辑:我已经更新了,以显示我的最新编辑 – 注意’parent_params [:relatives_attributes] .each do | k,r |’在控制器中.这样现在可以保存孩子的记录,但唯一的问题是它也保存了空白的字段!所以我的“亲戚”记录为空值为孩子记录.我如何阻止它保存空字段(或创建空的相对记录)?
解决方法
答案是建立相对的每个子记录,如下所示:
- parent_params[:relatives_attributes].each do |k,r|
- @parent.relatives.build(r.except(:_destroy))
- end
在调用@ parent.save之前.
但是,我仍然有摆脱空白记录的问题.所以如果任何人有这个问题的答案,请在这里评论 – 或者如果有更好或更传统的做法,打我.跟进问题在这里:Why is this reject_if in my model not rejecting blank records?