Class: Runt::WeekInterval

Inherits:
Object
  • Object
show all
Includes:
TExpr
Defined in:
lib/runt/temporalexpression.rb

Overview

This class creates an expression which matches dates occuring during the weeks alternating at the given interval begining on the week containing the date used to create the instance. 

WeekInterval.new(starting_date, interval)

Weeks are defined as Sunday to Saturday, as opposed to the commercial week which starts on a Monday. For example,

every_other_week = WeekInterval.new(Date.new(2013,04,24), 2)

will match any date that occurs during every other week begining with the week of 2013-04-21 (2013-04-24 is a Wednesday and 2013-04-21 is the Sunday that begins the containing week).

# Sunday of starting week
every_other_week.include?(Date.new(2013,04,21)) #==> true     
# Saturday of starting week
every_other_week.include?(Date.new(2013,04,27)) #==> true
# First week _after_ start week     
every_other_week.include?(Date.new(2013,05,01)) #==> false     
# Second week _after_ start week     
every_other_week.include?(Date.new(2013,05,06)) #==> true

NOTE: The idea and tests for this class were originally contributed as the REWeekWithIntervalTE class by Jeff Whitmire. The behavior of the original class provided both the matching of every n weeks and the specification of specific days of that week in a single class. This class only provides the matching of every n weeks. The exact functionality of the original class is easy to create using the Runt set operators and the DIWeek class:

# Old way
tu_thurs_every_third_week = REWeekWithIntervalTE.new(Date.new(2013,04,24),2,[2,4])

# New way
tu_thurs_every_third_week = 
    WeekInterval.new(Date.new(2013,04,24),2) & (DIWeek.new(Tuesday) | DIWeek.new(Thursday))

Notice that the compound expression (in parens after the “&”) can be replaced or combined with any other appropriate temporal expression to provide different functionality (REWeek to provide a range of days, REDay to provide certain times, etc…).

Contributed by Jeff Whitmire

Instance Method Summary collapse

Methods included from TExpr

#&, #-, #and, #dates, #minus, #or, #|

Constructor Details

#initialize(start_date, interval = 2) ⇒ WeekInterval

Returns a new instance of WeekInterval.



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# File 'lib/runt/temporalexpression.rb', line 869

def initialize(start_date,interval=2)
  @start_date = DPrecision.to_p(start_date,DPrecision::DAY)
  # convert base_date to the start of the week
  @base_date = @start_date - @start_date.wday
  @interval = interval
end

Instance Method Details

#include?(date) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/runt/temporalexpression.rb', line 876

def include?(date)
	return false if @base_date > date
	((adjust_for_year(date) - week_num(@base_date)) % @interval) == 0 
end

#to_s ⇒ Object 



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# File 'lib/runt/temporalexpression.rb', line 881

def to_s
  "every #{Runt.ordinalize(@interval)} week starting with the week containing #{Runt.format_date(@start_date)}"
end