Adding TimeZone#at and DateTime#to_f

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9042 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Adding TimeZone#at and DateTime#to_f [Geoff Buesing]
+
 * TimeWithZone responds to Ruby 1.9 weekday-named query methods [Geoff Buesing]
 
 * TimeWithZone caches TZInfo::TimezonePeriod used for time conversion so that it can be reused, and enforces DST rules correctly when instance is created from a local time [Geoff Buesing]

activesupport/lib/active_support/core_ext/date_time/conversions.rb

@@ -78,6 +78,12 @@ def to_datetime
         def xmlschema
           strftime("%Y-%m-%dT%H:%M:%S%Z")
         end if RUBY_VERSION < '1.9'
+        
+        # Converts self to a floating-point number of seconds since the Unix epoch 
+        def to_f
+          days_since_unix_epoch = self - ::DateTime.civil(1970)
+          (days_since_unix_epoch * 86_400).to_f
+        end
       end
     end
   end

activesupport/lib/active_support/time_with_zone.rb

@@ -160,7 +160,7 @@ def -(other)
     end unless RUBY_VERSION < '1.9'
     
     def to_a
-      time.to_a[0, 8].push(dst?, zone)
+      [time.sec, time.min, time.hour, time.day, time.mon, time.year, time.wday, time.yday, dst?, zone]
     end
     
     def to_f

activesupport/lib/active_support/values/time_zone.rb

@@ -178,7 +178,7 @@ def to_s
   begin # the following methods depend on the tzinfo gem
     require_library_or_gem "tzinfo" unless Object.const_defined?(:TZInfo)
     
-    # Method for creating new ActiveSupport::TimeWithZone instance in time zone of +self+. Example:
+    # Method for creating new ActiveSupport::TimeWithZone instance in time zone of +self+ from given values. Example:
     #
     #   Time.zone = "Hawaii"                      # => "Hawaii"
     #   Time.zone.local(2007, 2, 1, 15, 30, 45)   # => Thu, 01 Feb 2007 15:30:45 HST -10:00
@@ -186,6 +186,16 @@ def local(*args)
       time = Time.utc_time(*args)
       ActiveSupport::TimeWithZone.new(nil, self, time)
     end
+
+    # Method for creating new ActiveSupport::TimeWithZone instance in time zone of +self+ from number of seconds since the Unix epoch. Example:
+    #
+    #   Time.zone = "Hawaii"        # => "Hawaii"
+    #   Time.utc(2000).to_f         # => 946684800.0
+    #   Time.zone.at(946684800.0)   # => Fri, 31 Dec 1999 14:00:00 HST -10:00
+    def at(secs)
+      utc = Time.at(secs).utc rescue DateTime.civil(1970).since(secs)
+      utc.in_time_zone(self)
+    end
     
     # Returns an ActiveSupport::TimeWithZone instance representing the current time
     # in the time zone represented by +self+. Example:
@@ -234,7 +244,7 @@ def tzinfo
     
   rescue LoadError # Tzinfo gem is not available
     # re-raise LoadError only when a tzinfo-dependent method is called:
-    %w(local now today utc_to_local local_to_utc period_for_utc period_for_local tzinfo).each do |method|
+    %w(local at now today utc_to_local local_to_utc period_for_utc period_for_local tzinfo).each do |method|
       define_method(method) {|*args| raise LoadError, "TZInfo gem is required for TimeZone##{method}. `gem install tzinfo` and try again."}
     end
   end

activesupport/test/core_ext/date_time_ext_test.rb

@@ -271,6 +271,11 @@ def test_compare_with_time_with_zone
     assert_equal  0, DateTime.civil(2000) <=> ActiveSupport::TimeWithZone.new( Time.utc(2000, 1, 1, 0, 0, 0), TimeZone['UTC'] )
     assert_equal(-1, DateTime.civil(2000) <=> ActiveSupport::TimeWithZone.new( Time.utc(2000, 1, 1, 0, 0, 1), TimeZone['UTC'] ))
   end
+  
+  def test_to_f
+    assert_equal 946684800.0, DateTime.civil(2000).to_f
+    assert_equal 946684800.0, DateTime.civil(1999,12,31,19,0,0,Rational(-5,24)).to_f
+  end
 
   protected
     def with_env_tz(new_tz = 'US/Eastern')

activesupport/test/time_zone_test.rb

@@ -185,6 +185,25 @@ def test_local_enforces_fall_dst_rules
     assert_equal true, twz.dst? 
     assert_equal 'EDT', twz.zone
   end
+  
+  def test_at
+    zone = TimeZone['Eastern Time (US & Canada)']
+    secs = 946684800.0
+    twz = zone.at(secs)
+    assert_equal Time.utc(1999,12,31,19), twz.time
+    assert_equal Time.utc(2000), twz.utc
+    assert_equal zone, twz.time_zone
+    assert_equal secs, twz.to_f
+  end
+  
+  def test_at_with_old_date
+    zone = TimeZone['UTC']
+    secs = -3786825600.0
+    twz = zone.at(secs)
+    assert_equal [0,0,0,1,1,1850], twz.to_a[0,6]
+    assert_equal zone, twz.time_zone
+    assert_equal secs, twz.to_f
+  end
 
   protected
     def with_env_tz(new_tz = 'US/Eastern')