require 'tzinfo'
module ActiveSupport
# 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 ENV['TZ'] zone
class TimeWithZone
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
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 Time.zone, 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 Time.local() instance of the simultaneous time in your system's ENV['TZ'] zone
def localtime
utc.getlocal
end
alias_method :getlocal, :localtime
def dst?
period.dst?
end
alias_method :isdst, :dst?
def utc?
time_zone.name == 'UTC'
end
alias_method :gmt?, :utc?
def utc_offset
period.utc_total_offset
end
alias_method :gmt_offset, :utc_offset
alias_method :gmtoff, :utc_offset
def formatted_offset(colon = true, alternate_utc_string = nil)
utc? && alternate_utc_string || utc_offset.to_utc_offset_s(colon)
end
# Time uses #zone to display the time zone abbreviation, so we're duck-typing it
def zone
period.zone_identifier.to_s
end
def inspect
"#{time.strftime('%a, %d %b %Y %H:%M:%S')} #{zone} #{formatted_offset}"
end
def xmlschema
"#{time.strftime("%Y-%m-%dT%H:%M:%S")}#{formatted_offset(true, 'Z')}"
end
alias_method :iso8601, :xmlschema
def to_json(options = nil)
if ActiveSupport.use_standard_json_time_format
utc.xmlschema.inspect
else
%("#{time.strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)}")
end
end
def to_yaml(options = {})
if options.kind_of?(YAML::Emitter)
utc.to_yaml(options)
else
time.to_yaml(options).gsub('Z', formatted_offset(true, 'Z'))
end
end
def httpdate
utc.httpdate
end
def rfc2822
to_s(:rfc822)
end
alias_method :rfc822, :rfc2822
# :db format outputs time in UTC; all others output time in local. Uses TimeWithZone's strftime, so %Z and %z work correctly
def to_s(format = :default)
return utc.to_s(format) if format == :db
if 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 1.9 Time#to_s format
end
end
# Replaces %Z and %z directives with #zone and #formatted_offset, respectively, before passing to
# Time#strftime, so that zone information is correct
def strftime(format)
format = format.gsub('%Z', zone).gsub('%z', formatted_offset(false))
time.strftime(format)
end
# Use the time in UTC for comparisons
def <=>(other)
utc <=> other
end
def between?(min, max)
utc.between?(min, max)
end
def eql?(other)
utc == other
end
# If wrapped #time is a DateTime, use DateTime#since instead of #+
# Otherwise, just pass on to #method_missing
def +(other)
result = utc.acts_like?(:date) ? utc.since(other) : utc + other
result.in_time_zone(time_zone)
end
# If a time-like object is passed in, compare it with #utc
# Else if wrapped #time is a DateTime, use DateTime#ago instead of #-
# Otherwise, just pass on to method missing
def -(other)
if other.acts_like?(:time)
utc - other
else
result = utc.acts_like?(:date) ? utc.ago(other) : utc - other
result.in_time_zone(time_zone)
end
end
def since(other)
utc.since(other).in_time_zone(time_zone)
end
def ago(other)
utc.ago(other).in_time_zone(time_zone)
end
def advance(options)
utc.advance(options).in_time_zone(time_zone)
end
def usec
time.respond_to?(:usec) ? time.usec : 0
end
def to_a
[time.sec, time.min, time.hour, time.day, time.mon, time.year, time.wday, time.yday, dst?, zone]
end
def to_f
utc.to_f
end
def to_i
utc.to_i
end
alias_method :hash, :to_i
alias_method :tv_sec, :to_i
# A TimeWithZone acts like a Time, so just return self
def to_time
self
end
def to_datetime
utc.to_datetime.new_offset(Rational(utc_offset, 86_400))
end
# so that self acts_like?(:time)
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?
# Neuter freeze because freezing can cause problems with lazy loading of attributes
def freeze
self
end
def marshal_dump
[utc, time_zone.name, time]
end
def marshal_load(variables)
initialize(variables[0], ::Time.send!(:get_zone, variables[1]), variables[2])
end
# Ensure proxy class responds to all methods that underlying time instance responds to
def respond_to?(sym)
# consistently respond false to acts_like?(:date), regardless of whether #time is a Time or DateTime
return false if sym.to_s == 'acts_like_date?'
super || time.respond_to?(sym)
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)
result = time.__send__(sym, *args, &block)
result.acts_like?(:time) ? self.class.new(nil, time_zone, result) : result
end
private
def get_period_and_ensure_valid_local_time
# 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
@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(time.year, time.month, time.day, time.hour, time.min, time.sec, time.respond_to?(:usec) ? time.usec : 0)
end
end
end
