Active Record Tweaks

Active Record is great, but could be better. Here are some tweaks for it.

Support

=========== Tested against:

• Active Record of version 3.2 and 4.0
• Ruby 1.9.3, 2.0.0 (except Rails 4 with 1.9.2)

Install

gem 'active_record_tweaks'

Usage

Either include it in specific record or just ActiveRecord::Base

class SomeRecord
  include ActiveRecordTweaks
end 

# or

# In a initialzer
ActiveRecord::Base.send(:include, ActiveRecordTweaks)

#cache_key_without_timestamp

Nothing special, just like record.cache_key
But it has no timestamp so you can use it for scoped cache key
(e.g. When caching with Cookie, which you want to control the expiry time independent of record update time)
Usage:

  # Just like using #cache_key
  record.cache_key_without_timestamp

.cache_key

There is no class level cache key for ActiveRecord at the moment (4.0.1)
Passing an array to cache_digest could lead to performance issue and the key can become too long when collection is big
(rails#12726)
This is used for getting a cache key for a ActiveRecord class for all record (I don't know how to write one for Relation, could be similar)
You can use it for class level caching (like displaying all Categories or a random list of 5 users
And the cache would only expire when there is any record created, updated, or deleted (since count and maximum of updated_at are used)

Person.count # => 1000
Person.maximum(:updated_at) # => 20131106012125528738000
Person.cache_key # => "people/all/1000-20131106012125528738000"

Usage:

RecordClass.cache_key

You can also use it with multiple records (Rails 4 Record might have updated_at and updated_on)

RecordClass.cache_key(:updated_at, :updated_on)