Random list of ActiveSupport goodies

I recently browsed through the ActiveSupport code and found some nice stuff I did not know about:

ActiveSupport::Callbacks Show archive.org snapshot

ActiveRecord-like callbacks, if you need callbacks in non ActiveRecord objects

ActiveSupport::MessageEncryptor Show archive.org snapshot

encrypt and decrypt ruby objects

ActiveSupport::MessageVerifier Show archive.org snapshot

sign and verify ruby objects

ActiveSupport::OrderedOptions Show archive.org snapshot

like an ordered hash, but the keys can also be accessed like methods

Copyh = ActiveSupport::OrderedOptions.new
h['foo'] = 'bar'
h.foo = 'bar'  # same thing
h['foo']       # => 'bar'
h.foo          # => 'bar'

in? Show archive.org snapshot (> 3.0 only)

reverse of Array#include?

Copycharacters = ["Konata", "Kagami", "Tsukasa"]
"Konata".in?(characters)  # => true

Array.wrap Show archive.org snapshot

wraps argument in an array, unless it is array-like already. The behaviour is a bit saner than Array[...].

CopyArray.wrap(nil)           # => []
Array.wrap([1,2,3])       # => [1,2,3]
Array.wrap(1)             # => [1]
Array.wrap("foo \n bar")  # => ["foo \n bar"]

Class.class_attributes Show archive.org snapshot (> 3.0 only)

inheritable class attributes. Subclasses inherit from their parents, but cannot override their values

Copyclass Base
  class_attribute :setting
end
	
class Subclass < Base
end
	
Base.setting = true
Subclass.setting            # => true
Subclass.setting = false
Subclass.setting            # => false
Base.setting                # => true

Float#round Show archive.org snapshot

round to a given number of decimals

Copy1.2345.round(2)  # => 1.23
1.2345.round(3)  # => 1.235

Hash#deep_merge(!) Show archive.org snapshot

merge hashes recursively

String#squish(!) Show archive.org snapshot

removes leading and trailing whitespace, and converts all internal whitespace to single spaces

Copy%{ Multi-line
   string }.squish                    # => "Multi-line string"
" foo   bar    \n   \t   boo".squish  # => "foo bar boo"

Time.current, Date.current, DateTime.current Show archive.org snapshot

behaves like .now or .zone.now depending on whether a time zone is set