Ruby + OOP：我的子類期望@shipping_address IV有不同的數據類型嗎？

Question

在我的子類中，我的實例變量是不同的類型嗎？或者，這是紅寶石和動態打字的美麗的一部分？

例：

我有一個超UpsShipping具有可變的一個實例@shipping_method

這是我的第一個子類：

class UpsShippingQuote < UpsShipping 

    def ship_to 
    { 
     "CompanyName" => shipping_address.company, #<-- expects an object that responds to company, etc 
     "AttentionName" => shipping_address.name, 
     "PhoneNumber" => shipping_address.phone, 
     "Address" => recipient_address, 
     "ResidentialAddress" => nil 
    } 
    end 

    def recipient_address 
    { 
     "AddressLine1" => shipping_address.address, 
     "AddressLine2" => shipping_address.address_2, 
     "City" => shipping_address.city, 
     "StateProvinceCode" => shipping_address.state.code, 
     "CountryCode" => 'US', 
     "PostalCode" => shipping_address.postal_code 
    } 
    end 

和第2個亞類：

class UpsShippingEstimator < UpsShipping 

    def ship_to 
    { 
     "CompanyName" => "Test", 
     "AttentionName" => "Test", 
     "PhoneNumber" => "1231231234", 
     "Address" => recipient_address, 
     "ResidentialAddress" => nil 
    } 
    end 

    def recipient_address 
    { 
     "AddressLine1" => "Test", 
     "City" => shipping_address['city'], #<-- Expects a hash 
     "StateProvinceCode" => shipping_address['state'], 
     "CountryCode" => 'US', 
     "PostalCode" => shipping_address['zip_code'] 
    } 
    end 

所以在UpsShippingQuote，它期望噸他shipping_method是我Address模型的實例，但在UpsShippingEstimator，它預計shipping_method是一個散列的一個實例。

這樣好嗎？或者這是一種代碼味道，我正在做繼承錯誤？或者，我正在做得很好，因爲我正在利用動態輸入？

Answer 1

我認爲你應該只接受一個散列或者像散列一樣的東西。這是一個你可以給別人的界面。

對象是封裝知識的一種方式，所以您可以更好地向其他人解釋它。如果兒童使用不同的參數，則不能記錄該對象。

在另一方面，你可以使用一個哈希作爲一個接口：

class UpsShippingQuote < UpsShipping 

    def ship_to 
    { 
     "CompanyName" => shipping_address['company'], #<-- expects an object that responds to company, etc 
     "AttentionName" => shipping_address.['name'], 
     "PhoneNumber" => shipping_address.['phone'], 
     "Address" => recipient_address, 
     "ResidentialAddress" => nil 
    } 
    end 

end 

這將ActiveRecord工作，但你也可以啓用此行爲對於其他寶石類與方法：

def [] attribute 
    public_send(attribute) 
end 

而這應該使任何Ruby類嘎嘎作爲一個哈希。