ruby-on-rails - 带有集合的acts_as_taggable_on

Question

我有一个属于某个类别的产品列表。每个产品都有标签。请参阅以下示例（伪代码）

Category = transport
Products = car, train, bus

car has tags = small, fast
train has tags = fast, large
bus has tags = slow, large

如何列出运输类别中产品的所有标签？结果应该是 ["small", "fast", "large", "slow"]

Answer 1

定义一个数组来保存产品的标签。遍历属于该类别的产品。我假设，你已经建立了关系。从数组中删除重复项（如果有）。

@tags = [] 
@category.products.each { |p| @tags << p.tags }
@tags.uniq!