lib/core_ext/time_with_zone.rb
require 'core_ext/duration'
require 'core_ext/time_zone'
require 'core_ext/object/acts_like'
module CoreExt
# A Time-like class that can represent a time in any time zone. Necessary
# because standard Ruby Time instances are limited to UTC and the
# system's <tt>ENV['TZ']</tt> zone.
#
# You shouldn't ever need to create a TimeWithZone instance directly via +new+.
# Instead use methods +local+, +parse+, +at+ and +now+ on TimeZone instances,
# and +in_time_zone+ on Time and DateTime instances.
#
# Time.zone = 'Eastern Time (US & Canada)' # => 'Eastern Time (US & Canada)'
# Time.zone.local(2007, 2, 10, 15, 30, 45) # => Sat, 10 Feb 2007 15:30:45 EST -05:00
# Time.zone.parse('2007-02-10 15:30:45') # => Sat, 10 Feb 2007 15:30:45 EST -05:00
# Time.zone.at(1171139445) # => Sat, 10 Feb 2007 15:30:45 EST -05:00
# Time.zone.now # => Sun, 18 May 2008 13:07:55 EDT -04:00
# Time.utc(2007, 2, 10, 20, 30, 45).in_time_zone # => Sat, 10 Feb 2007 15:30:45 EST -05:00
#
# See Time and TimeZone for further documentation of these methods.
#
# TimeWithZone instances implement the same API as Ruby Time instances, so
# that Time and TimeWithZone instances are interchangeable.
#
# t = Time.zone.now # => Sun, 18 May 2008 13:27:25 EDT -04:00
# t.hour # => 13
# t.dst? # => true
# t.utc_offset # => -14400
# t.zone # => "EDT"
# t.to_s(:rfc822) # => "Sun, 18 May 2008 13:27:25 -0400"
# t + 1.day # => Mon, 19 May 2008 13:27:25 EDT -04:00
# t.beginning_of_year # => Tue, 01 Jan 2008 00:00:00 EST -05:00
# t > Time.utc(1999) # => true
# t.is_a?(Time) # => true
# t.is_a?(CoreExt::TimeWithZone) # => true
class TimeWithZone
# Report class name as 'Time' to thwart type checking.
def self.name
'Time'
end
PRECISIONS = Hash.new { |h, n| h[n] = "%FT%T.%#{n}N".freeze }
PRECISIONS[0] = '%FT%T'.freeze
include Comparable
attr_reader :time_zone
def initialize(utc_time, time_zone, local_time = nil, period = nil)
@utc, @time_zone, @time = utc_time, time_zone, local_time
@period = @utc ? period : get_period_and_ensure_valid_local_time(period)
end
# Returns a Time or DateTime instance that represents the time in +time_zone+.
def time
@time ||= period.to_local(@utc)
end
# Returns a Time or DateTime instance that represents the time in UTC.
def utc
@utc ||= period.to_utc(@time)
end
alias_method :comparable_time, :utc
alias_method :getgm, :utc
alias_method :getutc, :utc
alias_method :gmtime, :utc
# Returns the underlying TZInfo::TimezonePeriod.
def period
@period ||= time_zone.period_for_utc(@utc)
end
# Returns the simultaneous time in <tt>Time.zone</tt>, or the specified zone.
def in_time_zone(new_zone = ::Time.zone)
return self if time_zone == new_zone
utc.in_time_zone(new_zone)
end
# Returns a <tt>Time.local()</tt> instance of the simultaneous time in your
# system's <tt>ENV['TZ']</tt> zone.
def localtime(utc_offset = nil)
utc.respond_to?(:getlocal) ? utc.getlocal(utc_offset) : utc.to_time.getlocal(utc_offset)
end
alias_method :getlocal, :localtime
# Returns true if the current time is within Daylight Savings Time for the
# specified time zone.
#
# Time.zone = 'Eastern Time (US & Canada)' # => 'Eastern Time (US & Canada)'
# Time.zone.parse("2012-5-30").dst? # => true
# Time.zone.parse("2012-11-30").dst? # => false
def dst?
period.dst?
end
alias_method :isdst, :dst?
# Returns true if the current time zone is set to UTC.
#
# Time.zone = 'UTC' # => 'UTC'
# Time.zone.now.utc? # => true
# Time.zone = 'Eastern Time (US & Canada)' # => 'Eastern Time (US & Canada)'
# Time.zone.now.utc? # => false
def utc?
period.offset.abbreviation == :UTC || period.offset.abbreviation == :UCT
end
alias_method :gmt?, :utc?
# Returns the offset from current time to UTC time in seconds.
def utc_offset
period.utc_total_offset
end
alias_method :gmt_offset, :utc_offset
alias_method :gmtoff, :utc_offset
# Returns a formatted string of the offset from UTC, or an alternative
# string if the time zone is already UTC.
#
# Time.zone = 'Eastern Time (US & Canada)' # => "Eastern Time (US & Canada)"
# Time.zone.now.formatted_offset(true) # => "-05:00"
# Time.zone.now.formatted_offset(false) # => "-0500"
# Time.zone = 'UTC' # => "UTC"
# Time.zone.now.formatted_offset(true, "0") # => "0"
def formatted_offset(colon = true, alternate_utc_string = nil)
utc? && alternate_utc_string || TimeZone.seconds_to_utc_offset(utc_offset, colon)
end
# Returns the time zone abbreviation.
#
# Time.zone = 'Eastern Time (US & Canada)' # => "Eastern Time (US & Canada)"
# Time.zone.now.zone # => "EST"
def zone
period.zone_identifier.to_s
end
# Returns a string of the object's date, time, zone and offset from UTC.
#
# Time.zone.now.inspect # => "Thu, 04 Dec 2014 11:00:25 EST -05:00"
def inspect
"#{time.strftime('%a, %d %b %Y %H:%M:%S')} #{zone} #{formatted_offset}"
end
# Returns a string of the object's date and time in the ISO 8601 standard
# format.
#
# Time.zone.now.xmlschema # => "2014-12-04T11:02:37-05:00"
def xmlschema(fraction_digits = 0)
"#{time.strftime(PRECISIONS[fraction_digits.to_i])}#{formatted_offset(true, 'Z'.freeze)}"
end
alias_method :iso8601, :xmlschema
# Coerces time to a string for JSON encoding. The default format is ISO 8601.
# You can get %Y/%m/%d %H:%M:%S +offset style by setting
# <tt>CoreExt::JSON::Encoding.use_standard_json_time_format</tt>
# to +false+.
#
# # With CoreExt::JSON::Encoding.use_standard_json_time_format = true
# Time.utc(2005,2,1,15,15,10).in_time_zone("Hawaii").to_json
# # => "2005-02-01T05:15:10.000-10:00"
#
# # With CoreExt::JSON::Encoding.use_standard_json_time_format = false
# Time.utc(2005,2,1,15,15,10).in_time_zone("Hawaii").to_json
# # => "2005/02/01 05:15:10 -1000"
def as_json(options = nil)
if CoreExt::JSON::Encoding.use_standard_json_time_format
xmlschema(CoreExt::JSON::Encoding.time_precision)
else
%(#{time.strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)})
end
end
def init_with(coder) #:nodoc:
initialize(coder['utc'], coder['zone'], coder['time'])
end
def encode_with(coder) #:nodoc:
coder.tag = '!ruby/object:CoreExt::TimeWithZone'
coder.map = { 'utc' => utc, 'zone' => time_zone, 'time' => time }
end
# Returns a string of the object's date and time in the format used by
# HTTP requests.
#
# Time.zone.now.httpdate # => "Tue, 01 Jan 2013 04:39:43 GMT"
def httpdate
utc.httpdate
end
# Returns a string of the object's date and time in the RFC 2822 standard
# format.
#
# Time.zone.now.rfc2822 # => "Tue, 01 Jan 2013 04:51:39 +0000"
def rfc2822
to_s(:rfc822)
end
alias_method :rfc822, :rfc2822
# Returns a string of the object's date and time.
# Accepts an optional <tt>format</tt>:
# * <tt>:default</tt> - default value, mimics Ruby Time#to_s format.
# * <tt>:db</tt> - format outputs time in UTC :db time. See Time#to_formatted_s(:db).
# * Any key in <tt>Time::DATE_FORMATS</tt> can be used. See core_ext/core_ext/time/conversions.rb.
def to_s(format = :default)
if format == :db
utc.to_s(format)
elsif formatter = ::Time::DATE_FORMATS[format]
formatter.respond_to?(:call) ? formatter.call(self).to_s : strftime(formatter)
else
"#{time.strftime("%Y-%m-%d %H:%M:%S")} #{formatted_offset(false, 'UTC')}" # mimicking Ruby Time#to_s format
end
end
alias_method :to_formatted_s, :to_s
# Replaces <tt>%Z</tt> directive with +zone before passing to Time#strftime,
# so that zone information is correct.
def strftime(format)
format = format.gsub(/((?:\A|[^%])(?:%%)*)%Z/, "\\1#{zone}")
getlocal(utc_offset).strftime(format)
end
# Use the time in UTC for comparisons.
def <=>(other)
utc <=> other
end
# Returns true if the current object's time is within the specified
# +min+ and +max+ time.
def between?(min, max)
utc.between?(min, max)
end
# Returns true if the current object's time is in the past.
def past?
utc.past?
end
# Returns true if the current object's time falls within
# the current day.
def today?
time.today?
end
# Returns true if the current object's time is in the future.
def future?
utc.future?
end
# Returns +true+ if +other+ is equal to current object.
def eql?(other)
other.eql?(utc)
end
def hash
utc.hash
end
# Adds an interval of time to the current object's time and returns that
# value as a new TimeWithZone object.
#
# Time.zone = 'Eastern Time (US & Canada)' # => 'Eastern Time (US & Canada)'
# now = Time.zone.now # => Sun, 02 Nov 2014 01:26:28 EDT -04:00
# now + 1000 # => Sun, 02 Nov 2014 01:43:08 EDT -04:00
#
# If we're adding a Duration of variable length (i.e., years, months, days),
# move forward from #time, otherwise move forward from #utc, for accuracy
# when moving across DST boundaries.
#
# For instance, a time + 24.hours will advance exactly 24 hours, while a
# time + 1.day will advance 23-25 hours, depending on the day.
#
# now + 24.hours # => Mon, 03 Nov 2014 00:26:28 EST -05:00
# now + 1.day # => Mon, 03 Nov 2014 01:26:28 EST -05:00
def +(other)
if duration_of_variable_length?(other)
method_missing(:+, other)
else
result = utc.acts_like?(:date) ? utc.since(other) : utc + other rescue utc.since(other)
result.in_time_zone(time_zone)
end
end
alias_method :since, :+
# Returns a new TimeWithZone object that represents the difference between
# the current object's time and the +other+ time.
#
# Time.zone = 'Eastern Time (US & Canada)' # => 'Eastern Time (US & Canada)'
# now = Time.zone.now # => Mon, 03 Nov 2014 00:26:28 EST -05:00
# now - 1000 # => Mon, 03 Nov 2014 00:09:48 EST -05:00
#
# If subtracting a Duration of variable length (i.e., years, months, days),
# move backward from #time, otherwise move backward from #utc, for accuracy
# when moving across DST boundaries.
#
# For instance, a time - 24.hours will go subtract exactly 24 hours, while a
# time - 1.day will subtract 23-25 hours, depending on the day.
#
# now - 24.hours # => Sun, 02 Nov 2014 01:26:28 EDT -04:00
# now - 1.day # => Sun, 02 Nov 2014 00:26:28 EDT -04:00
def -(other)
if other.acts_like?(:time)
to_time - other.to_time
elsif duration_of_variable_length?(other)
method_missing(:-, other)
else
result = utc.acts_like?(:date) ? utc.ago(other) : utc - other rescue utc.ago(other)
result.in_time_zone(time_zone)
end
end
# Subtracts an interval of time from the current object's time and returns
# the result as a new TimeWithZone object.
#
# Time.zone = 'Eastern Time (US & Canada)' # => 'Eastern Time (US & Canada)'
# now = Time.zone.now # => Mon, 03 Nov 2014 00:26:28 EST -05:00
# now.ago(1000) # => Mon, 03 Nov 2014 00:09:48 EST -05:00
#
# If we're subtracting a Duration of variable length (i.e., years, months,
# days), move backward from #time, otherwise move backward from #utc, for
# accuracy when moving across DST boundaries.
#
# For instance, <tt>time.ago(24.hours)</tt> will move back exactly 24 hours,
# while <tt>time.ago(1.day)</tt> will move back 23-25 hours, depending on
# the day.
#
# now.ago(24.hours) # => Sun, 02 Nov 2014 01:26:28 EDT -04:00
# now.ago(1.day) # => Sun, 02 Nov 2014 00:26:28 EDT -04:00
def ago(other)
since(-other)
end
# Uses Date to provide precise Time calculations for years, months, and days
# according to the proleptic Gregorian calendar. The result is returned as a
# new TimeWithZone object.
#
# The +options+ parameter takes a hash with any of these keys:
# <tt>:years</tt>, <tt>:months</tt>, <tt>:weeks</tt>, <tt>:days</tt>,
# <tt>:hours</tt>, <tt>:minutes</tt>, <tt>:seconds</tt>.
#
# If advancing by a value of variable length (i.e., years, weeks, months,
# days), move forward from #time, otherwise move forward from #utc, for
# accuracy when moving across DST boundaries.
#
# Time.zone = 'Eastern Time (US & Canada)' # => 'Eastern Time (US & Canada)'
# now = Time.zone.now # => Sun, 02 Nov 2014 01:26:28 EDT -04:00
# now.advance(seconds: 1) # => Sun, 02 Nov 2014 01:26:29 EDT -04:00
# now.advance(minutes: 1) # => Sun, 02 Nov 2014 01:27:28 EDT -04:00
# now.advance(hours: 1) # => Sun, 02 Nov 2014 01:26:28 EST -05:00
# now.advance(days: 1) # => Mon, 03 Nov 2014 01:26:28 EST -05:00
# now.advance(weeks: 1) # => Sun, 09 Nov 2014 01:26:28 EST -05:00
# now.advance(months: 1) # => Tue, 02 Dec 2014 01:26:28 EST -05:00
# now.advance(years: 1) # => Mon, 02 Nov 2015 01:26:28 EST -05:00
def advance(options)
# If we're advancing a value of variable length (i.e., years, weeks, months, days), advance from #time,
# otherwise advance from #utc, for accuracy when moving across DST boundaries
if options.values_at(:years, :weeks, :months, :days).any?
method_missing(:advance, options)
else
utc.advance(options).in_time_zone(time_zone)
end
end
%w(year mon month day mday wday yday hour min sec usec nsec to_date).each do |method_name|
class_eval <<-EOV, __FILE__, __LINE__ + 1
def #{method_name} # def month
time.#{method_name} # time.month
end # end
EOV
end
# Returns Array of parts of Time in sequence of
# [seconds, minutes, hours, day, month, year, weekday, yearday, dst?, zone].
#
# now = Time.zone.now # => Tue, 18 Aug 2015 02:29:27 UTC +00:00
# now.to_a # => [27, 29, 2, 18, 8, 2015, 2, 230, false, "UTC"]
def to_a
[time.sec, time.min, time.hour, time.day, time.mon, time.year, time.wday, time.yday, dst?, zone]
end
# Returns the object's date and time as a floating point number of seconds
# since the Epoch (January 1, 1970 00:00 UTC).
#
# Time.zone.now.to_f # => 1417709320.285418
def to_f
utc.to_f
end
# Returns the object's date and time as an integer number of seconds
# since the Epoch (January 1, 1970 00:00 UTC).
#
# Time.zone.now.to_i # => 1417709320
def to_i
utc.to_i
end
alias_method :tv_sec, :to_i
# Returns the object's date and time as a rational number of seconds
# since the Epoch (January 1, 1970 00:00 UTC).
#
# Time.zone.now.to_r # => (708854548642709/500000)
def to_r
utc.to_r
end
# Returns an instance of Time in the system timezone.
def to_time
utc.to_time
end
# Returns an instance of DateTime with the timezone's UTC offset
#
# Time.zone.now.to_datetime # => Tue, 18 Aug 2015 02:32:20 +0000
# Time.current.in_time_zone('Hawaii').to_datetime # => Mon, 17 Aug 2015 16:32:20 -1000
def to_datetime
utc.to_datetime.new_offset(Rational(utc_offset, 86_400))
end
# So that +self+ <tt>acts_like?(:time)</tt>.
def acts_like_time?
true
end
# Say we're a Time to thwart type checking.
def is_a?(klass)
klass == ::Time || super
end
alias_method :kind_of?, :is_a?
# An instance of CoreExt::TimeWithZone is never blank
def blank?
false
end
def freeze
period; utc; time # preload instance variables before freezing
super
end
def marshal_dump
[utc, time_zone.name, time]
end
def marshal_load(variables)
initialize(variables[0].utc, ::Time.find_zone(variables[1]), variables[2].utc)
end
# respond_to_missing? is not called in some cases, such as when type conversion is
# performed with Kernel#String
def respond_to?(sym, include_priv = false)
# ensure that we're not going to throw and rescue from NoMethodError in method_missing which is slow
return false if sym.to_sym == :to_str
super
end
# Ensure proxy class responds to all methods that underlying time instance
# responds to.
def respond_to_missing?(sym, include_priv)
# consistently respond false to acts_like?(:date), regardless of whether #time is a Time or DateTime
return false if sym.to_sym == :acts_like_date?
time.respond_to?(sym, include_priv)
end
# Send the missing method to +time+ instance, and wrap result in a new
# TimeWithZone with the existing +time_zone+.
def method_missing(sym, *args, &block)
wrap_with_time_zone time.__send__(sym, *args, &block)
rescue NoMethodError => e
raise e, e.message.sub(time.inspect, self.inspect), e.backtrace
end
private
def get_period_and_ensure_valid_local_time(period)
# we don't want a Time.local instance enforcing its own DST rules as well,
# so transfer time values to a utc constructor if necessary
@time = transfer_time_values_to_utc_constructor(@time) unless @time.utc?
begin
period || @time_zone.period_for_local(@time)
rescue ::TZInfo::PeriodNotFound
# time is in the "spring forward" hour gap, so we're moving the time forward one hour and trying again
@time += 1.hour
retry
end
end
def transfer_time_values_to_utc_constructor(time)
::Time.utc(time.year, time.month, time.day, time.hour, time.min, time.sec, Rational(time.nsec, 1000))
end
def duration_of_variable_length?(obj)
CoreExt::Duration === obj && obj.parts.any? {|p| [:years, :months, :days].include?(p[0]) }
end
def wrap_with_time_zone(time)
if time.acts_like?(:time)
periods = time_zone.periods_for_local(time)
self.class.new(nil, time_zone, time, periods.include?(period) ? period : nil)
elsif time.is_a?(Range)
wrap_with_time_zone(time.begin)..wrap_with_time_zone(time.end)
else
time
end
end
end
end