Rails routing using custom attribute rather than table column

问题

Using Rails 4.2, I want to create a custom route using an attr_accessor rather than a table column, but I can't get the resource_path method to work.

I want custom route like this: /foos/the-title-parameterized-1 (where "1" is the id of the object).

Foo model:

#...
attr_accessor :slug
#dynamically generate a slug:
def slug
  "#{self.title.parameterize[0..200]}-#{self.id}"
end
#...

routes.rb:

get 'foos/:slug' => 'foos#show', :as => 'foo'

foos_controller.rb:

def show
  @foo = Foo.find params[:slug].split("-").last.to_i
end

In my show view, when I use helper method foo_path it returns the route using the id of the object rather than the slug like this: /foos/1. Is it possible to get this helper method to use the accessor method? Am I off track with this approach?

I would prefer to use Friendly Id but I dont believe its possible without creating a slug column in my model table. I dont want to create a column because there are millions of records.

回答1:

You want to override the to_param method in your model:

class Foo < ActiveRecord::Base
  # ...
  def to_param
    slug
  end

  # or
  alias :to_param :slug
end

You may also want to use the :constraints option in your route so that only URLs that match e.g. /-\d+\z/ are matched.

Keep in mind also that, using this method, the path /foos/i-am-not-this-foos-slug-123 will lead to the same record as /foos/i-am-this-foos-slug-123.

来源：https://stackoverflow.com/questions/41658221/rails-routing-using-custom-attribute-rather-than-table-column

标签

ruby-on-rails

routes