Methods
C
T
Instance Public methods
cache_key()

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

Examples

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

Source: show | on GitHub 

# File activerecord/lib/active_record/integration.rb, line 37
def cache_key
  case
  when new_record?
    "#{self.class.model_name.cache_key}/new"
  when timestamp = self[:updated_at]
    timestamp = timestamp.utc.to_s(:number)
    "#{self.class.model_name.cache_key}/#{id}-#{timestamp}"
  else
    "#{self.class.model_name.cache_key}/#{id}"
  end
end
to_param()

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

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"

Source: show | on GitHub 

# 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