如何更新AR模型上属性的属性?
我正在使用piggybakgem 。
我有一个产品q
:
1.9.3p194 :009 > q => #<Product id: 20, name: "iPad", description: "\r\n\tiPad 11" tablet that will change the way...", price: 499.0, vendor_id: 11, created_at: "2012-12-15 23:40:27", updated_at: "2013-01-01 00:18:39", image: "ipad.png", sku: "AB-09123">
q
有一个属性piggybak_sellable
,它有其他属性。
1.9.3p194 :010 > q.piggybak_sellable => nil
这是在Rails管理UI中分配的Product
可用属性的示例。
1.9.3p194 :011 > p.piggybak_sellable => #<Piggybak::Sellable id: 1, sku: "AR4590", description: "Blue Shirt", price: #, quantity: 100, item_id: 19, item_type: "Product", active: true, unlimited_inventory: false>
我想将这些属性添加到nil
记录中。
我想更新q.piggybak_sellable
所有属性,而不必手动完成,即设置q.piggybak_sellable.sku = "ARJHR"
等。
我尝试做update_attributes
但它不起作用:
1.9.3p194 :008 > q.piggybak_sellable.update_attributes(:sku => "YJ4567", :description => "Awesome tablet", :price => 399, :quantity => 100, :item_id => 20, :item_type => "Product", :active => true) NoMethodError: undefined method `update_attributes' for nil:NilClass
关于如何做到这一点的想法?
我试图将它放在我的Product
模型的回调中 – 这是值得的。
谢谢。
如果对象已存在(如收到的错误消息所指示),则更新属性有效。 尝试这样的事情:
1.9.3p194 :008 > q.piggybak_sellable.create(:sku => "YJ4567", :description => "Awesome tablet", :price => 399, :quantity => 100, :item_id => 20, :item_type => "Product", :active => true)
因此,我需要做的是将我的产品的piggybak_sellable
属性设置为等于Piggybak::Sellable
类的实例,可以这样做:
1.9.3p194 :006 > m.piggybak_sellable = Piggybak::Sellable.new({:sku => "YJ4567", :description => "Awesome tablet", :price => 399, :quantity => 50, :item_id => 20, :item_type => "Product", :active => true}) (0.3ms) begin transaction Piggybak::Sellable Exists (18.7ms) SELECT 1 AS one FROM "sellables" WHERE "sellables"."sku" = 'YJ4567' LIMIT 1 SQL (29.6ms) INSERT INTO "sellables" ("active", "description", "item_id", "item_type", "price", "quantity", "sku", "unlimited_inventory") VALUES (?, ?, ?, ?, ?, ?, ?, ?) [["active", true], ["description", "Awesome tablet"], ["item_id", 20], ["item_type", "Product"], ["price", #], ["quantity", 50], ["sku", "YJ4567"], ["unlimited_inventory", false]] (2.7ms) commit transaction => #, quantity: 50, item_id: 20, item_type: "Product", active: true, unlimited_inventory: false>
正如marcamillion已经说过的那样,至少在某些情况下,您的关联显然不存在。 现在的问题是你怎么能让它静默初始化,以便在关联不存在时不会破坏它。 我会尝试这样做:
( q.piggybak_sellable || q.build_piggyback_sellable ). update_attributes(:sku => "YJ4567", :description => "Awesome tablet", :price => 399, :quantity => 100, :item_id => 20, :item_type => "Product", :active => true)