Rails 2.3.3: Touching, faster JSON, bug fixes

We’ve released Ruby on Rails version 2.3.3. This release fixes a lot of bugs and introduces a handful of new features.

Active Record

• touch is a convenient method to update a record’s timestamp and nothing else. This is extracted from apps whose models “touch” others when they change, such as a comment updating the parent.replies_changed_at timestamp after save and destroy. Timestamping an entire has_many association makes it easy to build a key for fragment caching that covers changes to the parent object and any of its children. This pattern is wrapped up as belongs_to :parent, :touch => :replies_changed_at. When the child changes, parent.replies_changed_at is touched. :touch => true is defaults to :touch => :updated_at.
• :primary_key option for belongs_to for broader support of legacy schemas and those using a separate UUID primary key: belongs_to :employee, :primary_key => 'SSN', :foreign_key => 'EMPID' changeset

JSON

• decoding backends for the json and yajl libraries. Both are significantly faster than the default YAML backend. To get started, install the json gem and set ActiveSupport::JSON.backend = 'JSONGem'.
• leaner user-facing encoding API. Since a JSON libraries implement to_json with varying compatibility, safely overriding it is difficult. Most custom to_json looks like

  
  def to_json(*encoder_specific_args)
    { :some => "json representation" }.to_json(*encoder_specific_args)
  end

  so we DRYed the user-facing API down to a more natural

  
  def as_json(options = {})
    { :some => "json representation" }
  end

  without the ugly internal state exposed by overloading to_json as both public-facing and internal builder API. Rails 3 splits the API explicitly, so prepare now by switching from to_json to as_json.

Other Features

• Add :concat option to asset tag helpers to force concatenation. changeset
• Restore backwards compatibility for AR::Base#to_xml. changeset
• Move from BlueCloth to Markdown for the markdown helper. Users using BlueCloth to provide their markdown functionality should upgrade to version 1.0.1 or 2.0.5 in order to restore compatibility.

Notable Bug Fixes

• Fix errors caused by class-reloading with streaming responses in development mode.
• Several fixes to the gem bundling, unpacking and installing system.
• Make text_area_tag escape contents by default.
• Make filter_parameters work correctly with array parameters.
• Thread-safety fixes for postgresql string quoting.
• Performance fixes for large response bodies.