The following are some of the smaller, but notable features added to Rails 1.2 ActiveSupport since the Rails 1.1 release. (compiled by Joshua Sierles).
Module#unloadable marks constants that require unloading after each request. Example:
CONFIG.unloadable
Module#alias_attribute clones class attributes, including their getter, setter and query methods. Example:
class Email < ActiveRecord::Base
alias_attribute :subject, :title
end
e = Email.find(1)
e.title # => "Superstars"
e.subject # => "Superstars"
e.subject? # => true
e.subject = "Megastars"
e.title # => "Megastars"
Enumerable#sum calculates a sum from the array elements. Examples:
[1, 2, 3].sum
payments.sum { |p| p.price * p.tax_rate }
payments.sum(&:price)
This replaces: payments.inject(0) { |sum, p| sum + p.price }
Array#to_s(:db) produces a comma-separated list of ids. Example:
Purchase.find(:all, :conditions => "product_id IN (#{shops.products.to_s(:db)})"
Module#alias_method_chain encapsulates the common pattern:
alias_method :foo_without_feature, :foo
alias_method :foo, :foo_with_feature
With alias_method_chain:
alias_method_chain :foo, :feature
Array#split divides arrays into one or more subarrays by value or block. Examples:
[1, 2, 3, 4, 5].split(3) => [[1, 2], [4, 5]]
(1..10).to_a.split { |i| i % 3 == 0 } # => [[1, 2], [4, 5], [7, 8], [10]]
Hash.from_xml(string) creates a hash from an XML string, typecasting its elements if possible. Example:
Hash.from_xml <<-EOT
<note>
<title>This is a note</title>
<created-at type="date">2004-10-10</created-at>
</note>
EOT
...would return:
{ :note => { :title => "This is a note", :created_at => Date.new(2004, 10, 10) } }
The Builder package has been upgraded to version 2.0. Changes include:
-- UTF-8 characters in data are now correctly translated to their XML equivalents
-- Attribute values are now escaped by default