ruby-on-rails - 如何从 ActiveRecord CollectionProxy 获取值？

Question

我在遍历集合属性以获取值时遇到问题。

这是我的代理

<ActiveRecord::Associations::CollectionProxy [#<Product id: 12, name: "test", cost_in_cents: 4400, created_at: "2014-10-31 17:18:58", updated_at: "2014-10-31 17:18:58", subscription: nil, product_type: "One Time">, #<Product id: 14, name: "aggg", cost_in_cents: 1400, created_at: "2014-10-31 17:28:19", updated_at: "2014-10-31 17:28:19", subscription: nil, product_type: "One Time">]>

我希望能够像这样遍历代理中的所有对象。

my_collection_proxy.each do |c| c.name end

但这似乎不起作用。如何获取代理中每个名称的值？

输出:

@order.products.each do |a| a.name end
=> [#<Product id: 12, store_front_id: 8, name: "test", cost_in_cents: 4400, created_at: "2014-10-31 17:18:58", updated_at: "2014-10-31 17:18:58", subscription: nil, product_type: "One Time">, #<Product id: 14, store_front_id: 8, name: "aggg", cost_in_cents: 1400, created_at: "2014-10-31 17:28:19", updated_at: "2014-10-31 17:28:19", subscription: nil, product_type: "One Time">]

我希望我的输出看起来像什么:

=> test
=> aggg

Answer 1

如果你想把所有的名字放到一个数组中，你应该使用 Enumerable#collect:

names = @order.products.collect(&:name)