了解Rails模型中的slug_candidates方法

时间:2018-03-31 09:37:54

标签: ruby-on-rails ruby friendly-url friendly-id

我正在尝试在我的Rails应用中创建漂亮的网址。我无法理解模型中#slug_candidates方法内发生的事情。

class News < ApplicationRecord
  friendly_id :slug_candidates, use: [:slugged, :finders, :history]
  def slug_candidates 
    [:title,
      [:title, :id]
    ] 
  end
end

answer中也找到了类似的方法:

def slug_candidates
  [
    :name,
    [:name, 2],
    [:name, 3],
    [:name, 4],
    [:name, 5],
    [:name, 6],
    [:name, 7]
  ]
end

有人可以提供该方法的简要说明吗?

1 个答案:

答案 0 :(得分:3)

如果我们有2个news具有相同的标题,slugs将是相同的。所以我们无法识别它们。例如:

New.all
# => [#<New id: 1, tile: "Title">, #<New id: 2, tile: "Title">]

# Without `slug_candidates`
New.first # => URL: "news/title"
New.second # => URL: "news/title"
# => We cannot find the second one.

现在slug_candidates提供了一个变种列表,而FriendlyId将遍历该列表,直到找到尚未采取的slug为止。

# With `slug_candidates`
def slug_candidates 
  [:title, [:title, :id]]
end

New.first # => URL: "news/title"
New.second # => URL: "news/title-2"