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

   1 require 'active_support/duration'
   2
   3 module ActiveSupport #:nodoc:
   4   module CoreExtensions #:nodoc:
   5     module Time #:nodoc:
   6       # Enables the use of time calculations within Time itself
   7       module Calculations
   8         def self.included(base) #:nodoc:
   9           base.extend ClassMethods
  10
  11           base.class_eval do
  12             alias_method :plus_without_duration, :+
  13             alias_method :+, :plus_with_duration
  14
  15             alias_method :minus_without_duration, :-
  16             alias_method :-, :minus_with_duration
  17
  18             alias_method :minus_without_coercion, :-
  19             alias_method :-, :minus_with_coercion
  20
  21             alias_method :compare_without_coercion, :<=>
  22             alias_method :<=>, :compare_with_coercion
  23           end
  24         end
  25
  26         COMMON_YEAR_DAYS_IN_MONTH = [nil, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
  27
  28         module ClassMethods
  29           # Overriding case equality method so that it returns true for ActiveSupport::TimeWithZone instances
  30           def ===(other)
  31             other.is_a?(::Time)
  32           end
  33
  34           # Return the number of days in the given month.
  35           # If no year is specified, it will use the current year.
  36           def days_in_month(month, year = now.year)
  37             return 29 if month == 2 && ::Date.gregorian_leap?(year)
  38             COMMON_YEAR_DAYS_IN_MONTH[month]
  39           end
  40
  41           # Returns a new Time if requested year can be accommodated by Ruby's Time class
  42           # (i.e., if year is within either 1970..2038 or 1902..2038, depending on system architecture);
  43           # otherwise returns a DateTime
  44           def time_with_datetime_fallback(utc_or_local, year, month=1, day=1, hour=0, min=0, sec=0, usec=0)
  45             ::Time.send(utc_or_local, year, month, day, hour, min, sec, usec)
  46           rescue
  47             offset = utc_or_local.to_sym == :local ? ::DateTime.local_offset : 0
  48             ::DateTime.civil(year, month, day, hour, min, sec, offset)
  49           end
  50
  51           # Wraps class method +time_with_datetime_fallback+ with +utc_or_local+ set to <tt>:utc</tt>.
  52           def utc_time(*args)
  53             time_with_datetime_fallback(:utc, *args)
  54           end
  55
  56           # Wraps class method +time_with_datetime_fallback+ with +utc_or_local+ set to <tt>:local</tt>.
  57           def local_time(*args)
  58             time_with_datetime_fallback(:local, *args)
  59           end
  60         end
  61
  62         # Tells whether the Time object's time lies in the past
  63         def past?
  64           self < ::Time.current
  65         end
  66
  67         # Tells whether the Time object's time is today
  68         def today?
  69           self.to_date == ::Date.current
  70         end
  71
  72         # Tells whether the Time object's time lies in the future
  73         def future?
  74           self > ::Time.current
  75         end
  76
  77         # Seconds since midnight: Time.now.seconds_since_midnight
  78         def seconds_since_midnight
  79           self.to_i - self.change(:hour => 0).to_i + (self.usec/1.0e+6)
  80         end
  81
  82         # Returns a new Time where one or more of the elements have been changed according to the +options+ parameter. The time options
  83         # (hour, minute, sec, usec) reset cascadingly, so if only the hour is passed, then minute, sec, and usec is set to 0. If the hour and
  84         # minute is passed, then sec and usec is set to 0.
  85         def change(options)
  86           ::Time.send(
  87             self.utc? ? :utc_time : :local_time,
  88             options[:year]  || self.year,
  89             options[:month] || self.month,
  90             options[:day]   || self.day,
  91             options[:hour]  || self.hour,
  92             options[:min]   || (options[:hour] ? 0 : self.min),
  93             options[:sec]   || ((options[:hour] || options[:min]) ? 0 : self.sec),
  94             options[:usec]  || ((options[:hour] || options[:min] || options[:sec]) ? 0 : self.usec)
  95           )
  96         end
  97
  98         # Uses Date to provide precise Time calculations for years, months, and days.
  99         # The +options+ parameter takes a hash with any of these keys: <tt>:years</tt>,
 100         # <tt>:months</tt>, <tt>:weeks</tt>, <tt>:days</tt>, <tt>:hours</tt>,
 101         # <tt>:minutes</tt>, <tt>:seconds</tt>.
 102         def advance(options)
 103           unless options[:weeks].nil?
 104             options[:weeks], partial_weeks = options[:weeks].divmod(1)
 105             options[:days] = (options[:days] || 0) + 7 * partial_weeks
 106           end
 107
 108           unless options[:days].nil?
 109             options[:days], partial_days = options[:days].divmod(1)
 110             options[:hours] = (options[:hours] || 0) + 24 * partial_days
 111           end
 112
 113           d = to_date.advance(options)
 114           time_advanced_by_date = change(:year => d.year, :month => d.month, :day => d.day)
 115           seconds_to_advance = (options[:seconds] || 0) + (options[:minutes] || 0) * 60 + (options[:hours] || 0) * 3600
 116           seconds_to_advance == 0 ? time_advanced_by_date : time_advanced_by_date.since(seconds_to_advance)
 117         end
 118
 119         # Returns a new Time representing the time a number of seconds ago, this is basically a wrapper around the Numeric extension
 120         def ago(seconds)
 121           self.since(-seconds)
 122         end
 123
 124         # Returns a new Time representing the time a number of seconds since the instance time, this is basically a wrapper around
 125         # the Numeric extension.
 126         def since(seconds)
 127           f = seconds.since(self)
 128           if ActiveSupport::Duration === seconds
 129             f
 130           else
 131             initial_dst = self.dst? ? 1 : 0
 132             final_dst   = f.dst? ? 1 : 0
 133             (seconds.abs >= 86400 && initial_dst != final_dst) ? f + (initial_dst - final_dst).hours : f
 134           end
 135         rescue
 136           self.to_datetime.since(seconds)
 137         end
 138         alias :in :since
 139
 140         # Returns a new Time representing the time a number of specified months ago
 141         def months_ago(months)
 142           advance(:months => -months)
 143         end
 144
 145         # Returns a new Time representing the time a number of specified months in the future
 146         def months_since(months)
 147           advance(:months => months)
 148         end
 149
 150         # Returns a new Time representing the time a number of specified years ago
 151         def years_ago(years)
 152           advance(:years => -years)
 153         end
 154
 155         # Returns a new Time representing the time a number of specified years in the future
 156         def years_since(years)
 157           advance(:years => years)
 158         end
 159
 160         # Short-hand for years_ago(1)
 161         def last_year
 162           years_ago(1)
 163         end
 164
 165         # Short-hand for years_since(1)
 166         def next_year
 167           years_since(1)
 168         end
 169
 170
 171         # Short-hand for months_ago(1)
 172         def last_month
 173           months_ago(1)
 174         end
 175
 176         # Short-hand for months_since(1)
 177         def next_month
 178           months_since(1)
 179         end
 180
 181         # Returns a new Time representing the "start" of this week (Monday, 0:00)
 182         def beginning_of_week
 183           days_to_monday = self.wday!=0 ? self.wday-1 : 6
 184           (self - days_to_monday.days).midnight
 185         end
 186         alias :monday :beginning_of_week
 187         alias :at_beginning_of_week :beginning_of_week
 188
 189         # Returns a new Time representing the end of this week (Sunday, 23:59:59)
 190         def end_of_week
 191           days_to_sunday = self.wday!=0 ? 7-self.wday : 0
 192           (self + days_to_sunday.days).end_of_day
 193         end
 194         alias :at_end_of_week :end_of_week
 195
 196         # Returns a new Time representing the start of the given day in next week (default is Monday).
 197         def next_week(day = :monday)
 198           days_into_week = { :monday => 0, :tuesday => 1, :wednesday => 2, :thursday => 3, :friday => 4, :saturday => 5, :sunday => 6}
 199           since(1.week).beginning_of_week.since(days_into_week[day].day).change(:hour => 0)
 200         end
 201
 202         # Returns a new Time representing the start of the day (0:00)
 203         def beginning_of_day
 204           (self - self.seconds_since_midnight).change(:usec => 0)
 205         end
 206         alias :midnight :beginning_of_day
 207         alias :at_midnight :beginning_of_day
 208         alias :at_beginning_of_day :beginning_of_day
 209
 210         # Returns a new Time representing the end of the day (23:59:59)
 211         def end_of_day
 212           change(:hour => 23, :min => 59, :sec => 59)
 213         end
 214
 215         # Returns a new Time representing the start of the month (1st of the month, 0:00)
 216         def beginning_of_month
 217           #self - ((self.mday-1).days + self.seconds_since_midnight)
 218           change(:day => 1,:hour => 0, :min => 0, :sec => 0, :usec => 0)
 219         end
 220         alias :at_beginning_of_month :beginning_of_month
 221
 222         # Returns a new Time representing the end of the month (last day of the month, 0:00)
 223         def end_of_month
 224           #self - ((self.mday-1).days + self.seconds_since_midnight)
 225           last_day = ::Time.days_in_month( self.month, self.year )
 226           change(:day => last_day, :hour => 23, :min => 59, :sec => 59, :usec => 0)
 227         end
 228         alias :at_end_of_month :end_of_month
 229
 230         # Returns  a new Time representing the start of the quarter (1st of january, april, july, october, 0:00)
 231         def beginning_of_quarter
 232           beginning_of_month.change(:month => [10, 7, 4, 1].detect { |m| m <= self.month })
 233         end
 234         alias :at_beginning_of_quarter :beginning_of_quarter
 235
 236         # Returns a new Time representing the end of the quarter (last day of march, june, september, december, 23:59:59)
 237         def end_of_quarter
 238           beginning_of_month.change(:month => [3, 6, 9, 12].detect { |m| m >= self.month }).end_of_month
 239         end
 240         alias :at_end_of_quarter :end_of_quarter
 241
 242         # Returns  a new Time representing the start of the year (1st of january, 0:00)
 243         def beginning_of_year
 244           change(:month => 1,:day => 1,:hour => 0, :min => 0, :sec => 0, :usec => 0)
 245         end
 246         alias :at_beginning_of_year :beginning_of_year
 247
 248         # Returns a new Time representing the end of the year (31st of december, 23:59:59)
 249         def end_of_year
 250           change(:month => 12,:day => 31,:hour => 23, :min => 59, :sec => 59)
 251         end
 252         alias :at_end_of_year :end_of_year
 253
 254         # Convenience method which returns a new Time representing the time 1 day ago
 255         def yesterday
 256           advance(:days => -1)
 257         end
 258
 259         # Convenience method which returns a new Time representing the time 1 day since the instance time
 260         def tomorrow
 261           advance(:days => 1)
 262         end
 263
 264         def plus_with_duration(other) #:nodoc:
 265           if ActiveSupport::Duration === other
 266             other.since(self)
 267           else
 268             plus_without_duration(other)
 269           end
 270         end
 271
 272         def minus_with_duration(other) #:nodoc:
 273           if ActiveSupport::Duration === other
 274             other.until(self)
 275           else
 276             minus_without_duration(other)
 277           end
 278         end
 279
 280         # Time#- can also be used to determine the number of seconds between two Time instances.
 281         # We're layering on additional behavior so that ActiveSupport::TimeWithZone instances
 282         # are coerced into values that Time#- will recognize
 283         def minus_with_coercion(other)
 284           other = other.comparable_time if other.respond_to?(:comparable_time)
 285           minus_without_coercion(other)
 286         end
 287
 288         # Layers additional behavior on Time#<=> so that DateTime and ActiveSupport::TimeWithZone instances
 289         # can be chronologically compared with a Time
 290         def compare_with_coercion(other)
 291           # if other is an ActiveSupport::TimeWithZone, coerce a Time instance from it so we can do <=> comparison
 292           other = other.comparable_time if other.respond_to?(:comparable_time)
 293           if other.acts_like?(:date)
 294             # other is a Date/DateTime, so coerce self #to_datetime and hand off to DateTime#<=>
 295             to_datetime.compare_without_coercion(other)
 296           else
 297             compare_without_coercion(other)
 298           end
 299         end
 300       end
 301     end
 302   end
 303 end