diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/date_time')
-rw-r--r-- | activesupport/lib/active_support/core_ext/date_time/calculations.rb | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/date_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_time/calculations.rb new file mode 100644 index 0000000000..dd30dd07bc --- /dev/null +++ b/activesupport/lib/active_support/core_ext/date_time/calculations.rb @@ -0,0 +1,173 @@ +require 'rational' + +module ActiveSupport #:nodoc: + module CoreExtensions #:nodoc: + module DateTime #:nodoc: + # Enables the use of time calculations within DateTime itself + module Calculations + + # Seconds since midnight: DateTime.now.seconds_since_midnight + def seconds_since_midnight + self.sec + (self.min * 60) + (self.hour * 3600) + end + + # Returns a new DateTime where one or more of the elements have been changed according to the +options+ parameter. The time options + # (hour, minute, sec) reset cascadingly, so if only the hour is passed, then minute and sec is set to 0. If the hour and + # minute is passed, then sec is set to 0. + def change(options) + ::DateTime.civil( + options[:year] || self.year, + options[:month] || self.month, + options[:mday] || self.mday, + options[:hour] || self.hour, + options[:min] || (options[:hour] ? 0 : self.min), + options[:sec] || ((options[:hour] || options[:min]) ? 0 : self.sec), + options[:offset] || self.offset, + options[:start] || self.start + ) + end + + # Uses Date to provide precise Time calculations for years, months, and days. The +options+ parameter takes a hash with + # any of these keys: :months, :days, :years. + def advance(options) + d = ::Date.new(year + (options.delete(:years) || 0), month, day) + d = d >> options.delete(:months) if options[:months] + d = d + options.delete(:days) if options[:days] + change(options.merge(:year => d.year, :month => d.month, :mday => d.day)) + end + + # Returns a new DateTime representing the time a number of seconds ago + # Do not use this method in combination with x.months, use months_ago instead! + def ago(seconds) + self.since(-seconds) + end + + # Returns a new DateTime representing the time a number of seconds since the instance time + # Do not use this method in combination with x.months, use months_since instead! + def since(seconds) + self + Rational(seconds, 86400) + end + alias :in :since + + # Returns a new DateTime representing the time a number of specified months ago + def months_ago(months) + months_since(-months) + end + + def months_since(months) + year, month, mday = self.year, self.month, self.mday + + month += months + + # in case months is negative + while month < 1 + month += 12 + year -= 1 + end + + # in case months is positive + while month > 12 + month -= 12 + year += 1 + end + + max = ::Time.days_in_month(month, year) + mday = max if mday > max + + change(:year => year, :month => month, :mday => mday) + end + + # Returns a new DateTime representing the time a number of specified years ago + def years_ago(years) + change(:year => self.year - years) + end + + def years_since(years) + change(:year => self.year + years) + end + + # Short-hand for years_ago(1) + def last_year + years_ago(1) + end + + # Short-hand for years_since(1) + def next_year + years_since(1) + end + + # Short-hand for months_ago(1) + def last_month + months_ago(1) + end + + # Short-hand for months_since(1) + def next_month + months_since(1) + end + + # Returns a new DateTime representing the "start" of this week (Monday, 0:00) + def beginning_of_week + days_to_monday = self.wday!=0 ? self.wday-1 : 6 + (self - days_to_monday).midnight + end + alias :monday :beginning_of_week + alias :at_beginning_of_week :beginning_of_week + + # Returns a new DateTime representing the start of the given day in next week (default is Monday). + def next_week(day = :monday) + days_into_week = { :monday => 0, :tuesday => 1, :wednesday => 2, :thursday => 3, :friday => 4, :saturday => 5, :sunday => 6} + ((self + 7).beginning_of_week + days_into_week[day]).change(:hour => 0) + end + + # Returns a new DateTime representing the start of the day (0:00) + def beginning_of_day + change(:hour => 0) + end + alias :midnight :beginning_of_day + alias :at_midnight :beginning_of_day + alias :at_beginning_of_day :beginning_of_day + + # Returns a new DateTime representing the end of the day (23:59:59) + def end_of_day + change(:hour => 23, :min => 59, :sec => 59) + end + + # Returns a new DateTime representing the start of the month (1st of the month, 0:00) + def beginning_of_month + change(:mday => 1,:hour => 0, :min => 0, :sec => 0) + end + alias :at_beginning_of_month :beginning_of_month + + # Returns a new DateTime representing the end of the month (last day of the month, 0:00) + def end_of_month + last_day = ::Time.days_in_month( self.month, self.year ) + change(:mday => last_day,:hour => 0, :min => 0, :sec => 0) + end + alias :at_end_of_month :end_of_month + + # Returns a new DateTime representing the start of the quarter (1st of january, april, july, october, 0:00) + def beginning_of_quarter + beginning_of_month.change(:month => [10, 7, 4, 1].detect { |m| m <= self.month }) + end + alias :at_beginning_of_quarter :beginning_of_quarter + + # Returns a new DateTime representing the start of the year (1st of january, 0:00) + def beginning_of_year + change(:month => 1,:mday => 1,:hour => 0, :min => 0, :sec => 0) + end + alias :at_beginning_of_year :beginning_of_year + + # Convenience method which returns a new DateTime representing the time 1 day ago + def yesterday + self - 1 + end + + # Convenience method which returns a new DateTime representing the time 1 day since the instance time + def tomorrow + self + 1 + end + end + end + end +end |