Module: RiCal::CoreExtensions::Time::WeekDayPredicates

Included in:
Date, DateTime, Time
Defined in:
lib/ri_cal/core_extensions/time/week_day_predicates.rb

Overview

  • ©2009 Rick DeNatale

  • All rights reserved. Refer to the file README.txt for the license

Provide predicate and related methods for use by the RiCal gem This module is included by Time, Date, and DateTime

Instance Method Summary collapse

Instance Method Details

#nth_wday_in_month(n, which_wday, for_time = self) ⇒ Object

e.g. to obtain the 3nd Tuesday of the receivers month use

time.nth_wday_in_month(2, 2)



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# File 'lib/ri_cal/core_extensions/time/week_day_predicates.rb', line 53

def nth_wday_in_month(n, which_wday, for_time = self)
  first_of_month = for_time.to_ri_cal_property_value.change(:day => 1)
  first_in_month = first_of_month.advance(:days => (which_wday - first_of_month.wday))
  first_in_month = first_in_month.advance(:days => 7) if first_in_month.month != first_of_month.month
  if n > 0
    first_in_month.advance(:days => (7*(n - 1)))
  else
    possible = first_in_month.advance(:days => 21)
    possible = possible.advance(:days => 7) while possible.month == first_in_month.month
    last_in_month = possible.advance(:days => - 7)
    (last_in_month.advance(:days => - (7*(n.abs - 1))))
  end
end

#nth_wday_in_month?(n, which_wday) ⇒ Boolean

A predicate to determine whether or not the receiver falls on a particular weekday of its month.

Parameters

n

the ordinal number being requested

which_wday

the weekday using Ruby time conventions, i.e. 0 => Sunday, 1 => Monday, …

Returns:

  • (Boolean) 


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# File 'lib/ri_cal/core_extensions/time/week_day_predicates.rb', line 72

def nth_wday_in_month?(n, which_wday)
  target = nth_wday_in_month(n, which_wday)
  [self.year, self.month, self.day] == [target.year, target.month, target.day]
end

#nth_wday_in_year(n, which_wday, for_time = self) ⇒ Object

e.g. to obtain the 2nd Monday of the receivers year use

time.nth_wday_in_year(2, 1)



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# File 'lib/ri_cal/core_extensions/time/week_day_predicates.rb', line 20

def nth_wday_in_year(n, which_wday, for_time = self)
  if n > 0
    first_of_year = for_time.to_ri_cal_property_value.change(:month => 1, :day => 1)
    first_in_year = first_of_year.advance(:days => (which_wday - first_of_year.wday + 7) % 7)
    first_in_year.advance(:days => (7*(n - 1)))
  else
    december25 = for_time.to_ri_cal_property_value.change(:month => 12, :day => 25)
    last_in_year = december25.advance(:days => (which_wday - december25.wday + 7) % 7)
    last_in_year.advance(:days => (7 * (n + 1)))
  end
end

#nth_wday_in_year?(n, which_wday) ⇒ Boolean

A predicate to determine whether or not the receiver falls on a particular weekday of its year.

See #nth_wday_in_year

Parameters

n

the ordinal number being requested

which_wday

the weekday using Ruby time conventions, i.e. 0 => Sunday, 1 => Monday, …

Returns:

  • (Boolean) 


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# File 'lib/ri_cal/core_extensions/time/week_day_predicates.rb', line 39

def nth_wday_in_year?(n, which_wday)
  target = nth_wday_in_year(n, which_wday)
  [self.year, self.mon, self.day] == [target.year, target.mon, target.day]
end

#start_of_week_with_wkst(wkst) ⇒ Object

Return a DateTime which is the beginning of the first day on or before the receiver with the specified wday



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# File 'lib/ri_cal/core_extensions/time/week_day_predicates.rb', line 79

def start_of_week_with_wkst(wkst)
   wkst ||= 1
   date = ::Date.civil(self.year, self.month, self.day)
   date -= 1 while date.wday != wkst
   date
end