Introduce ActiveSupport::TimeWithZone, for wrapping Time instances with a TimeZone. Introduce instance methods to Time for creating TimeWithZone instances, and class methods for managing a global time zone

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8696 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 72 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/core_ext/date_time.rb b/activesupport/lib/active_support/core_ext/date_time.rb
index 1d711de70b..66a93eac43 100644
--- a/activesupport/lib/active_support/core_ext/date_time.rb
+++ b/activesupport/lib/active_support/core_ext/date_time.rb
@@ -1,10 +1,12 @@
 require 'date'
 require 'active_support/core_ext/time/behavior'
+require 'active_support/core_ext/time/zones'
 require 'active_support/core_ext/date_time/calculations'
 require 'active_support/core_ext/date_time/conversions'
 
 class DateTime
   include ActiveSupport::CoreExtensions::Time::Behavior
+  include ActiveSupport::CoreExtensions::Time::Zones
   include ActiveSupport::CoreExtensions::DateTime::Calculations
   include ActiveSupport::CoreExtensions::DateTime::Conversions
 end
diff --git a/activesupport/lib/active_support/core_ext/time.rb b/activesupport/lib/active_support/core_ext/time.rb
index d87c4ec65a..ea50511a96 100644
--- a/activesupport/lib/active_support/core_ext/time.rb
+++ b/activesupport/lib/active_support/core_ext/time.rb
@@ -11,9 +11,11 @@ end
 require 'active_support/core_ext/time/behavior'
 require 'active_support/core_ext/time/calculations'
 require 'active_support/core_ext/time/conversions'
+require 'active_support/core_ext/time/zones'
 
 class Time#:nodoc:
   include ActiveSupport::CoreExtensions::Time::Behavior
   include ActiveSupport::CoreExtensions::Time::Calculations
   include ActiveSupport::CoreExtensions::Time::Conversions
+  include ActiveSupport::CoreExtensions::Time::Zones
 end
diff --git a/activesupport/lib/active_support/core_ext/time/zones.rb b/activesupport/lib/active_support/core_ext/time/zones.rb
new file mode 100644
index 0000000000..563d522d9a
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/time/zones.rb
@@ -0,0 +1,68 @@
+module ActiveSupport #:nodoc:
+  module CoreExtensions #:nodoc:
+    module Time #:nodoc:
+      # Methods for creating TimeWithZone objects from Time instances
+      module Zones
+        
+        def self.included(base) #:nodoc:
+          base.extend(ClassMethods) if base == ::Time # i.e., don't include class methods in DateTime
+        end
+        
+        module ClassMethods
+          attr_reader :zone
+
+          # Sets a global default time zone, separate from the system time zone in ENV['TZ']. 
+          # Accepts either a Rails TimeZone object, a string that identifies a 
+          # Rails TimeZone object (e.g., "Central Time (US & Canada)"), or a TZInfo::Timezone object
+          #
+          # Any Time or DateTime object can use this default time zone, via #in_current_time_zone.
+          # Example:
+          #
+          #   Time.zone = 'Hawaii'                  # => 'Hawaii'
+          #   Time.utc(2000).in_current_time_zone   # => Fri, 31 Dec 1999 14:00:00 HST -10:00
+          def zone=(zone)
+            @zone = get_zone(zone)
+          end
+          
+          def zone_reset!
+            @zone = nil
+          end
+          
+          def get_zone(zone)
+            ::String === zone || ::Numeric === zone ? TimeZone[zone] : zone
+          end
+        end
+        
+        # Gives the corresponding time in the supplied zone. self is assumed to be in UTC regardless of constructor.
+        #
+        # Examples:
+        #
+        #   t = Time.utc(2000)        # => Sat Jan 01 00:00:00 UTC 2000
+        #   t.in_time_zone('Alaska')  # => Fri, 31 Dec 1999 15:00:00 AKST -09:00
+        #   t.in_time_zone('Hawaii')  # => Fri, 31 Dec 1999 14:00:00 HST -10:00
+        def in_time_zone(zone)
+          ActiveSupport::TimeWithZone.new(self, ::Time.get_zone(zone))
+        end
+
+        # Returns the simultaneous time in Time.zone
+        def in_current_time_zone
+          in_time_zone(::Time.zone)
+        end
+
+        # Replaces the existing zone; leaves time value intact. Examples:
+        #
+        #   t = Time.utc(2000)            # => Sat Jan 01 00:00:00 UTC 2000
+        #   t.change_time_zone('Alaska')  # => Sat, 01 Jan 2000 00:00:00 AKST -09:00
+        #   t.change_time_zone('Hawaii')  # => Sat, 01 Jan 2000 00:00:00 HST -10:00
+        def change_time_zone(zone)
+          ActiveSupport::TimeWithZone.new(nil, ::Time.get_zone(zone), self)
+        end
+
+        # Replaces the existing zone to Time.zone; leaves time value intact
+        def change_time_zone_to_current
+          change_time_zone(::Time.zone)
+        end
+      end
+    end
+  end
+end
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