For example, suppose that you have a User model, and that you have a resources :users route. Normally, user_path will construct a path with the user object’s ‘id’ in it:
user = User.find_by_name('Phusion') user_path(user) # => "/users/1"
You can override to_param in your model to make user_path construct a path using the user’s name instead of the user’s id:
class User < ActiveRecord::Base def to_param # overridden name end end user = User.find_by_name('Phusion') user_path(user) # => "/users/Phusion"
# File activerecord/lib/active_record/integration.rb, line 25 def to_param # We can't use alias_method here, because method 'id' optimizes itself on the fly. id && id.to_s # Be sure to stringify the id for routes end