This class has dubious semantics and we only have it so that people can write params instead of params and they get the same value for both keys.
The TimeZone class serves as a wrapper around TZInfo::Timezone instances. It allows us to do the following:
Limit the set of zones provided by TZInfo to a meaningful subset of 142 zones.
Retrieve and display zones with a friendlier name (e.g., "Eastern Time (US & Canada)" instead of "America/New_York").
Lazily load TZInfo::Timezone instances only when they're needed.
Create ActiveSupport::TimeWithZone instances via TimeZone's local, parse, at and now methods.
If you set config.time_zone in the Rails Application, you can access this TimeZone object via Time.zone:
# application.rb: class Application < Rails::Application config.time_zone = "Eastern Time (US & Canada)" end Time.zone # => #<TimeZone:0x514834...> Time.zone.name # => "Eastern Time (US & Canada)" Time.zone.now # => Sun, 18 May 2008 14:30:44 EDT -04:00
The version of TZInfo bundled with Active Support only includes the definitions necessary to support the zones defined by the TimeZone class. If you need to use zones that aren't defined by TimeZone, you'll need to install the TZInfo gem (if a recent version of the gem is installed locally, this will be used instead of the bundled version.)
OrderedHash is namespaced to prevent conflicts with other implementations
A typical module looks like this
module M def self.included(base) base.send(:extend, ClassMethods) base.send(:include, InstanceMethods) scope :foo, :conditions => { :created_at => nil } end module ClassMethods def cm; puts 'I am a class method'; end end module InstanceMethods def im; puts 'I am an instance method'; end end end
By using ActiveSupport::Concern the above module could instead be written as:
module M extend ActiveSupport::Concern included do scope :foo, :conditions => { :created_at => nil } end module ClassMethods def cm; puts 'I am a class method'; end end module InstanceMethods def im; puts 'I am an instance method'; end end end
lazy_load_hooks allows rails to lazily load a lot of components and thus making the app boot faster. Because of this feature now there is no need to require ActiveRecord::Base at boot time purely to apply configuration. Instead a hook is registered that applies configuration once ActiveRecord::Base is loaded. Here ActiveRecord::Base is used as example but this feature can be applied elsewhere too.
Here is an example where on_load method is called to register a hook.
initializer "active_record.initialize_timezone" do ActiveSupport.on_load(:active_record) do self.time_zone_aware_attributes = true self.default_timezone = :utc end end
When the entirety of activerecord/lib/active_record/base.rb has been evaluated then run_load_hooks is invoked. The very last line of activerecord/lib/active_record/base.rb is:
ActiveSupport.run_load_hooks(:active_record, ActiveRecord::Base)
Some code from jeremymcanally's "pending" github.com/jeremymcanally/pending/tree/master
Use Ruby's SecureRandom library if available.
# File lib/active_support/lazy_load_hooks.rb, line 32 def self.execute_hook(base, options, block) if options[:yield] block.call(base) else base.instance_eval(&block) end end
# File lib/active_support.rb, line 28 def load_all!; load_all_hooks.each { |hook| hook.call } end
# File lib/active_support/lazy_load_hooks.rb, line 24 def self.on_load(name, options = {}, &block) if base = @loaded[name] execute_hook(base, options, block) else @load_hooks[name] << [block, options] end end
Generated with the Darkfish Rdoc Generator 2.