如何在rails中實現對象組合？

Question

我是Rails框架的新手。我試圖創建一個非ActiveRecord支持的模型類，具有以下複合結構 -

{ 
    "address" : { 
     "city" : "Bangalore", 
     "state" : "KA" 
    }, 
    "images" : [ 
     "image-path-1", 
     "image-path-2" 
     "image-path-3" 
    ], 
    "facilities" : [ 
     { 
      "name" : "abcd" 
     }, 
     { 
      "name" : "xyz" 
     } 
    ] 
} 

如何去創建此複合模型？

Answer 1

在rails中，您將實現所謂的「Form」模型。對於Rails新手來說，這會向您介紹許多奇怪的「半高級」主題，但以下是您想要做的事情。我建議您查找任何您沒看過的方法/模塊，因爲在這裏背景中有一些神奇的導軌使用（驗證回調等）：

首先選擇一個類名...根據您提供的屬性我會打電話給班級公司。

class Company 

include ActiveModel::Model #This gives you access to the model methods you're used to. 
include ActiveModel::Validations::Callbacks #Needed for before_validation 

attr_accessor :address 
attr_accessor :images 
attr_accessor :facilities #This accessor method basically just says you will be using "facilities" as a virtual attribute and it will allow you to define it. 

#Add validations here as needed if you're taking these values from form inputs 

def initialize(params={}) #This will be executed when you call Company.new in your controller 
    self.facilities=params[:facilities] 
    #etc for the other fields you want to define just make sure you added them above with attr_accessor or you wont be able to define them. Attr_accessor is a pure ruby method if it's new to you. 
end 



    def another_method 
    unless self.facilities.somethingYourCheckingForLikeNil? 
    errors.add(:facilities, "This failed and what you checked for is not here!" 
    end 
    end 

end 

然後在您的控制器如果按照正常的流程，你會碰到這樣的：

def new 
    company = Company.new 
end 

def create 
    company = Company.new(company_params) 
    #whatever logic here for saving what you may want saved to a database table etc... 
end 


private 

def company_params 
    params.require(:company).permit(:facilities, :address, :whatever_other_params_etc) 
end 

沒有更多的信息，我不能給你一個完整的例子然而，這應該讓你的軌道上詳細瞭解「表單模型」。