vendor/rails/activesupport/lib/active_support/core_ext/time/zones.rb

   1 module ActiveSupport #:nodoc:
   2   module CoreExtensions #:nodoc:
   3     module Time #:nodoc:
   4       module Zones
   5         def self.included(base) #:nodoc:
   6           base.extend(ClassMethods) if base == ::Time # i.e., don't include class methods in DateTime
   7         end
   8
   9         module ClassMethods
  10           attr_accessor :zone_default
  11
  12           # Returns the TimeZone for the current request, if this has been set (via Time.zone=).
  13           # If <tt>Time.zone</tt> has not been set for the current request, returns the TimeZone specified in <tt>config.time_zone</tt>.
  14           def zone
  15             Thread.current[:time_zone] || zone_default
  16           end
  17
  18           # Sets <tt>Time.zone</tt> to a TimeZone object for the current request/thread.
  19           #
  20           # This method accepts any of the following:
  21           #
  22           # * A Rails TimeZone object.
  23           # * An identifier for a Rails TimeZone object (e.g., "Eastern Time (US & Canada)", <tt>-5.hours</tt>).
  24           # * A TZInfo::Timezone object.
  25           # * An identifier for a TZInfo::Timezone object (e.g., "America/New_York").
  26           #
  27           # Here's an example of how you might set <tt>Time.zone</tt> on a per request basis -- <tt>current_user.time_zone</tt>
  28           # just needs to return a string identifying the user's preferred TimeZone:
  29           #
  30           #   class ApplicationController < ActionController::Base
  31           #     before_filter :set_time_zone
  32           #
  33           #     def set_time_zone
  34           #       Time.zone = current_user.time_zone
  35           #     end
  36           #   end
  37           def zone=(time_zone)
  38             Thread.current[:time_zone] = get_zone(time_zone)
  39           end
  40
  41           # Allows override of <tt>Time.zone</tt> locally inside supplied block; resets <tt>Time.zone</tt> to existing value when done.
  42           def use_zone(time_zone)
  43             old_zone, ::Time.zone = ::Time.zone, get_zone(time_zone)
  44             yield
  45           ensure
  46             ::Time.zone = old_zone
  47           end
  48
  49           # Returns <tt>Time.zone.now</tt> when <tt>config.time_zone</tt> is set, otherwise just returns <tt>Time.now</tt>.
  50           def current
  51             ::Time.zone_default ? ::Time.zone.now : ::Time.now
  52           end
  53
  54           private
  55             def get_zone(time_zone)
  56               return time_zone if time_zone.nil? || time_zone.is_a?(TimeZone)
  57               # lookup timezone based on identifier (unless we've been passed a TZInfo::Timezone)
  58               unless time_zone.respond_to?(:period_for_local)
  59                 time_zone = TimeZone[time_zone] || TZInfo::Timezone.get(time_zone) rescue nil
  60               end
  61               # Return if a TimeZone instance, or wrap in a TimeZone instance if a TZInfo::Timezone
  62               if time_zone
  63                 time_zone.is_a?(TimeZone) ? time_zone : TimeZone.create(time_zone.name, nil, time_zone)
  64               end
  65             end
  66         end
  67
  68         # Returns the simultaneous time in <tt>Time.zone</tt>.
  69         #
  70         #   Time.zone = 'Hawaii'         # => 'Hawaii'
  71         #   Time.utc(2000).in_time_zone  # => Fri, 31 Dec 1999 14:00:00 HST -10:00
  72         #
  73         # This method is similar to Time#localtime, except that it uses <tt>Time.zone</tt> as the local zone
  74         # instead of the operating system's time zone.
  75         #
  76         # You can also pass in a TimeZone instance or string that identifies a TimeZone as an argument,
  77         # and the conversion will be based on that zone instead of <tt>Time.zone</tt>.
  78         #
  79         #   Time.utc(2000).in_time_zone('Alaska')  # => Fri, 31 Dec 1999 15:00:00 AKST -09:00
  80         def in_time_zone(zone = ::Time.zone)
  81           ActiveSupport::TimeWithZone.new(utc? ? self : getutc, ::Time.__send__(:get_zone, zone))
  82         end
  83       end
  84     end
  85   end
  86 end