如何设置 url helper 方法参数的默认值? [英] How to set defaults for parameters of url helper methods?

问题描述

我使用语言代码作为前缀，例如www.mydomain.com/en/posts/1.这就是我在 routes.rb 中所做的:

I use language code as a prefix, e.g. www.mydomain.com/en/posts/1. This is what I did in routes.rb:

scope ":lang" do
  resources :posts
end

现在我可以轻松使用 url 助手，例如:post_path(post.id, :lang => :en).问题是我想在 cookie 中使用一个值作为默认语言.所以我可以只写 post_path(post.id).

Now I can easily use url helpers such as: post_path(post.id, :lang => :en). The problem is that I would like to use a value in a cookie as a default language. So I could write just post_path(post.id).

有什么办法可以为 url helper 中的参数设置默认值?我找不到 url helper 的源代码 - 有人能指出我正确的方向吗?

Is there any way how to set default values for parameters in url helpers? I can't find the source code of url helpers - can someone point me in the right direction?

另一种方式:我已经尝试在 routes.rb 中设置它，但它仅在启动时进行评估，这对我不起作用:

Another way: I have already tried to set it in routes.rb but it's evaluated in startup time only, this does not work for me:

scope ":lang", :defaults => { :lang => lambda { "en" } } do
  resources :posts
end

推荐答案

这是我脑中的编码，所以不能保证，但在初始化程序中尝试一下:

This is coding from my head, so no guarantee, but give this a try in an initializer:

module MyRoutingStuff
  alias :original_url_for :url_for
  def url_for(options = {})
    options[:lang] = :en unless options[:lang]   # whatever code you want to set your default
    original_url_for
  end
end
ActionDispatch::Routing::UrlFor.send(:include, MyRoutingStuff)

或者直接的猴子补丁...

or straight monkey-patch...

module ActionDispatch
  module Routing
    module UrlFor
      alias :original_url_for :url_for
      def url_for(options = {})
        options[:lang] = :en unless options[:lang]   # whatever code you want to set your default
        original_url_for
      end
    end
  end
end

url_for 的代码在 Rails 3.0.7 中的 actionpack/lib/routing/url_for.rb 中

The code for url_for is in actionpack/lib/routing/url_for.rb in Rails 3.0.7

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