Rails多態關聯不會保存_type

我的項目中有幾個模型：Request，Work，Car和Employee。工作是Request和Car/Employee之間的中間模型。Rails多態關聯不會保存_type

這裏有關聯：

請求

has_many :works, dependent: :destroy 
def performers 
    works.map {|x| x.performer} 
end

工作

belongs_to :request 
belongs_to :performer, polymorphic: true

汽車

has_many :works, as: :performer 
has_many :requests, through: :works, as: :performer

員工

has_many :works, as: :performer 
has_many :requests, through: :works, as: :performer

查看用於創建工程：

<%= form_for([@request, @work]) do |f| %> 
    <%= (f.collection_select :performer_id, Employee.all, :id, :name) if @request.type == "StaffRequest" %> 
    <%= (f.collection_select :performer_id, Car.all, :id, :select_info) if @request.type == "CarRequest" %> 
    <%= f.submit 'OK' %> 
<% end %>

工作控制器

def new 
    @work = @request.works.new 
    end 

    def create 
    @work = @request.works.new(work_params) 
    end 

    def work_params 
     params.require(:work).permit(:performer_id, :request_id) 
    end

的PROBL em是我的performer_type列總是空的，它不保存類名。可能是什麼問題？有任何想法嗎？

來源

2016-12-30 Marat

你能提供你正在使用的代碼在'works'表中創建一行嗎？例如'Work.create'或'Employee.new（...）.save'？ – coreyward

在'has_many：requests'你爲什麼要加'as：performer'？「通過」應該足夠了。 – Deep

它是空的，因爲你我以前不通過它，你應該添加一個隱藏字段，用於形成：你必須通過performer_id：

<%= form_for([@request, @work]) do |f| %> 
    <% if @request.type == "StaffRequest" %> 
    <%= (f.hidden_field :performer_type, value: "Employee") %> 
    <%= (f.collection_select :performer_id, Employee.all, :id, :name) %> 
    <% elsif @request.type == "CarRequest" %> 
    <%= (f.hidden_field :performer_type, value: "Car") %> 
    <%= (f.collection_select :performer_id, Car.all, :id, :select_info) %> 
    <% end %> 
    <%= f.submit 'OK' %> 
<% end %>

來源

2016-12-30 09:39:45

我總是通過多態關聯類型來爲你計算rails的東西 – Marat

除了performer_type也，要做到這一點的一種方法是通過形式select_tag：

def create 
    @work = @request.works.new(work_params) 
end 

def work_params 
    # use :performer if you use :performer as in the select form field 
    params.require(:work).permit(:performer, :request_id) 

    # OR 

    # use :performer_id & :performer_type if you also use the hidden field 
    params.require(:work).permit(:performer_id, :performer_type, :request_id) 
end

這是一個很好的例子（爲Rails 4.2）使用單一的選擇表單域多態的，所以你可以這樣寫：

<%= f.grouped_collection_select :global_performer, [ Car, Employee ], :all, :model_name, :to_global_id, :name %>

How to create grouped select box in Rails for polymorphic association using Global ID?

來源

2016-12-30 09:55:13

Rails多態關聯不會保存_type

回答

相關問題