module ActiveRecord::Integration

Person.find(5).cache_key # => "people/5-20071224150000" (updated_at available)
Product.find(5).cache_key # => "products/5" (updated_at not available)
Product.new.cache_key # => "products/new"

Returns a cache key that can be used to identify this record.

def cache_key
  case
  when new_record?
    "#{self.class.model_name.cache_key}/new"
  when timestamp = max_updated_column_timestamp
    timestamp = timestamp.utc.to_s(cache_timestamp_format)
    "#{self.class.model_name.cache_key}/#{id}-#{timestamp}"
  else
    "#{self.class.model_name.cache_key}/#{id}"
  end
end

user_path(user) # => "/users/Phusion"
user = User.find_by(name: 'Phusion')

end
end
name
def to_param # overridden
class User < ActiveRecord::Base

a path using the user's name instead of the user's id:
You can override +to_param+ in your model to make +user_path+ construct

user_path(user) # => "/users/1"
user = User.find_by(name: 'Phusion')

construct a path with the user object's 'id' in it:
resources :users route. Normally, +user_path+ will
For example, suppose that you have a User model, and that you have a

or nil if this record's unsaved.
object. The default implementation returns this record's id as a String,
Returns a String, which Action Pack uses for constructing an URL to this

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