How to DRY Your Rails Routes
工作中经常会遇到一些资源之间要共享路由，就像 controller 和 model 的 concern 文件夹一样，Rails 4 开始对 routes 也提供了 concern 功能，而且用起来很简单。
concern :printable do
member do
post :print
end
end
resources :pamphlets, concerns: :printable
resources :posters, concerns: :printable do
collection do
post :bulk_print
end
end
看起来还不错，现在有一个需求，需要确保在浏览器的 JavaScript 禁用的情况下也能删除资源。
首先要给所有的 resources 都添加两个自定义的路由方法。我们可以这么写：
resources_types = %i(banners cities notifications categories expresses promotions)
resources_types.each do |type|
resources type do
get :delete
delete :delete, action: :destroy
end
end
这样写真的很麻烦，渐渐这个数组就会越来越长，而且有些还需要添加一些其它的路由。
这时候更好的办法是在 config/initializers 中添加一个 delete_resource_route.rb
module DeleteResourceRoute
def resources(*args, &block)
super(*args) do
yield if block_given?
member do
get :delete
delete :delete, action: :destroy
end
end
end
end
ActionDispatch::Routing::Mapper.send(:include, DeleteResourceRoute)
添加 app/views/application/delete.html.erb。
<%= form_tag request.url, method: :delete do %>
<h2>Are you sure you want to delete this record?</h2>
<p>
<%= submit_tag "Destroy" %>
<% if request.referrer.present? %>
or <%= link_to "cancel", request.referer %>
<% end %>
</p>
<% end %>
注意 Rails 的查找路径，application 是一个很好的放置共享文件的地方，过去我都是放在 shared 文件夹下，但是文档其实早就提过这个问题。
This makes app/views/application/ a great place for your shared partials
