require 'active_support/core_ext/string/filters' module ActiveRecord module Integration extend ActiveSupport::Concern included do ## # :singleton-method: # Indicates the format used to generate the timestamp in the cache key. # Accepts any of the symbols in Time::DATE_FORMATS. # # This is +:usec+, by default. class_attribute :cache_timestamp_format, :instance_writer => false self.cache_timestamp_format = :usec end # Returns a String, which Action Pack uses for constructing a 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" 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 # Returns a cache key that can be used to identify this record. # # 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) # # You can also pass a list of named timestamps, and the newest in the list will be # used to generate the key: # # Person.find(5).cache_key(:updated_at, :last_reviewed_at) def cache_key(*timestamp_names) case when new_record? "#{model_name.cache_key}/new" when timestamp_names.any? timestamp = max_updated_column_timestamp(timestamp_names) timestamp = timestamp.utc.to_s(cache_timestamp_format) "#{model_name.cache_key}/#{id}-#{timestamp}" when timestamp = max_updated_column_timestamp timestamp = timestamp.utc.to_s(cache_timestamp_format) "#{model_name.cache_key}/#{id}-#{timestamp}" else "#{model_name.cache_key}/#{id}" end end module ClassMethods # Defines your model's +to_param+ method to generate "pretty" URLs # using +method_name+, which can be any attribute or method that # responds to +to_s+. # # class User < ActiveRecord::Base # to_param :name # end # # user = User.find_by(name: 'Fancy Pants') # user.id # => 123 # user_path(user) # => "/users/123-fancy-pants" # # Values longer than 20 characters will be truncated. The value # is truncated word by word. # # user = User.find_by(name: 'David Heinemeier Hansson') # user.id # => 125 # user_path(user) # => "/users/125-david-heinemeier" # # Because the generated param begins with the record's +id+, it is # suitable for passing to +find+. In a controller, for example: # # params[:id] # => "123-fancy-pants" # User.find(params[:id]).id # => 123 def to_param(method_name = nil) if method_name.nil? super() else define_method :to_param do if (default = super()) && (result = send(method_name).to_s).present? && (param = result.squish.parameterize.truncate(20, separator: /-/, omission: '')).present? "#{default}-#{param}" else default end end end end end end end