Date.beginning_of_week thread local and beginning_of_week application config option added (default is Monday)

6 files changed, 121 insertions, 17 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 59e112e3f9..47f1c8458e 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   `Date.beginning_of_week` thread local and `beginning_of_week` application config option added (default is Monday). *Innokenty Mikhailov*
+
 *   An optional block can be passed to `config_accessor` to set its default value
 
         class User
diff --git a/activesupport/lib/active_support/core_ext/date/calculations.rb b/activesupport/lib/active_support/core_ext/date/calculations.rb
index 86badf4d29..ee23bc578c 100644
--- a/activesupport/lib/active_support/core_ext/date/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date/calculations.rb
@@ -9,6 +9,29 @@ class Date
   include DateAndTime::Calculations
 
   class << self
+    attr_accessor :beginning_of_week_default
+
+    # Returns the week start (e.g. :monday) for the current request, if this has been set (via Date.beginning_of_week=).
+    # If <tt>Date.beginning_of_week</tt> has not been set for the current request, returns the week start specified in <tt>config.beginning_of_week</tt>.
+    # If no config.beginning_of_week was specified, returns :monday.
+    def beginning_of_week
+      Thread.current[:beginning_of_week] || beginning_of_week_default || :monday
+    end
+
+    # Sets <tt>Date.beginning_of_week</tt> to a week start (e.g. :monday) for current request/thread.
+    #
+    # This method accepts any of the following day symbols:
+    # :monday, :tuesday, :wednesday, :thursday, :friday, :saturday, :sunday
+    def beginning_of_week=(week_start)
+      Thread.current[:beginning_of_week] = find_beginning_of_week!(week_start)
+    end
+
+    # Returns week start day symbol (e.g. :monday), or raises an ArgumentError for invalid day symbol.
+    def find_beginning_of_week!(week_start)
+      raise ArgumentError, "Invalid beginning of week: #{week_start}" unless ::Date::DAYS_INTO_WEEK.keys.include?(week_start)
+      week_start
+    end
+
     # Returns a new Date representing the date 1 day ago (i.e. yesterday's date).
     def yesterday
       ::Date.current.yesterday
diff --git a/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
index e703fca7a7..1f78b9eb5a 100644
--- a/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
@@ -109,10 +109,11 @@ module DateAndTime
     alias :at_beginning_of_year :beginning_of_year
 
     # Returns a new date/time representing the given day in the next week.
-    # Default is :monday.
+    # Week is assumed to start on +start_day+, default is
+    # +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
     # DateTime objects have their time set to 0:00.
-    def next_week(day = :monday)
-      first_hour{ weeks_since(1).beginning_of_week.days_since(DAYS_INTO_WEEK[day]) }
+    def next_week(start_day = Date.beginning_of_week)
+      first_hour{ weeks_since(1).beginning_of_week.days_since(days_span(start_day)) }
     end
 
     # Short-hand for months_since(1).
@@ -131,10 +132,11 @@ module DateAndTime
     end
 
     # Returns a new date/time representing the given day in the previous week.
-    # Default is :monday.
+    # Week is assumed to start on +start_day+, default is
+    # +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
     # DateTime objects have their time set to 0:00.
-    def prev_week(day = :monday)
-      first_hour{ weeks_ago(1).beginning_of_week.days_since(DAYS_INTO_WEEK[day]) }
+    def prev_week(start_day = Date.beginning_of_week)
+      first_hour{ weeks_ago(1).beginning_of_week.days_since(days_span(start_day)) }
     end
     alias_method :last_week, :prev_week
 
@@ -157,31 +159,44 @@ module DateAndTime
     alias_method :last_year, :prev_year
 
     # Returns the number of days to the start of the week on the given day.
-    # Default is :monday.
-    def days_to_week_start(start_day = :monday)
+    # Week is assumed to start on +start_day+, default is
+    # +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
+    def days_to_week_start(start_day = Date.beginning_of_week)
       start_day_number = DAYS_INTO_WEEK[start_day]
       current_day_number = wday != 0 ? wday - 1 : 6
       (current_day_number - start_day_number) % 7
     end
 
     # Returns a new date/time representing the start of this week on the given day.
-    # Default is :monday.
-    # DateTime objects have their time set to 0:00.
-    def beginning_of_week(start_day = :monday)
+    # Week is assumed to start on +start_day+, default is
+    # +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
+    # +DateTime+ objects have their time set to 0:00.
+    def beginning_of_week(start_day = Date.beginning_of_week)
       result = days_ago(days_to_week_start(start_day))
       acts_like?(:time) ? result.midnight : result
     end
     alias :at_beginning_of_week :beginning_of_week
-    alias :monday :beginning_of_week
+
+    # Returns Monday of this week assuming that week starts on Monday.
+    # +DateTime+ objects have their time set to 0:00.
+    def monday
+      beginning_of_week(:monday)
+    end
 
     # Returns a new date/time representing the end of this week on the given day.
-    # Default is :monday (i.e end of Sunday).
+    # Week is assumed to start on +start_day+, default is
+    # +Date.beginning_of_week+ or +config.beginning_of_week+ when set.
     # DateTime objects have their time set to 23:59:59.
-    def end_of_week(start_day = :monday)
+    def end_of_week(start_day = Date.beginning_of_week)
       last_hour{ days_since(6 - days_to_week_start(start_day)) }
     end
     alias :at_end_of_week :end_of_week
-    alias :sunday :end_of_week
+
+    # Returns Sunday of this week assuming that week starts on Monday.
+    # +DateTime+ objects have their time set to 23:59:59.
+    def sunday
+      end_of_week(:monday)
+    end
 
     # Returns a new date/time representing the end of the month.
     # DateTime objects will have a time set to 23:59:59.
@@ -209,5 +224,9 @@ module DateAndTime
       result = yield
       acts_like?(:time) ? result.end_of_day : result
     end
+
+    def days_span(day)
+      (DAYS_INTO_WEEK[day] - DAYS_INTO_WEEK[Date.beginning_of_week]) % 7
+    end
   end
 end
diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index 148f2c27f1..78baa80ccd 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -169,8 +169,9 @@ class Time
     beginning_of_day..end_of_day
   end
 
-  # Returns a Range representing the whole week of the current time. Week starts on start_day (default is :monday, i.e. end of Sunday).
-  def all_week(start_day = :monday)
+  # Returns a Range representing the whole week of the current time.
+  # Week starts on start_day, default is <tt>Date.week_start</tt> or <tt>config.week_start</tt> when set.
+  def all_week(start_day = Date.beginning_of_week)
     beginning_of_week(start_day)..end_of_week(start_day)
   end
 
diff --git a/activesupport/lib/active_support/railtie.rb b/activesupport/lib/active_support/railtie.rb
index aa8d408da9..29351db742 100644
--- a/activesupport/lib/active_support/railtie.rb
+++ b/activesupport/lib/active_support/railtie.rb
@@ -27,6 +27,15 @@ module ActiveSupport
       Time.zone_default = zone_default
     end
 
+    # Sets the default week start
+    # If assigned value is not a valid day symbol (e.g. :sunday, :monday, ...), an exception will be raised.
+    initializer "active_support.initialize_beginning_of_week" do |app|
+      require 'active_support/core_ext/date/calculations'
+      beginning_of_week_default = Date.find_beginning_of_week!(app.config.beginning_of_week)
+
+      Date.beginning_of_week_default = beginning_of_week_default
+    end
+
     initializer "active_support.set_configs" do |app|
       app.config.active_support.each do |k, v|
         k = "#{k}="
diff --git a/activesupport/test/core_ext/date_and_time_behavior.rb b/activesupport/test/core_ext/date_and_time_behavior.rb
index 014935b0c0..9927856aa2 100644
--- a/activesupport/test/core_ext/date_and_time_behavior.rb
+++ b/activesupport/test/core_ext/date_and_time_behavior.rb
@@ -101,6 +101,15 @@ module DateAndTimeBehavior
     assert_equal date_time_init(2006,11,1,0,0,0),  date_time_init(2006,10,23,0,0,0).next_week(:wednesday)
   end
 
+  def test_next_week_with_default_beginning_of_week_set
+    with_bw_default(:tuesday) do
+      assert_equal Time.local(2012, 3, 28), Time.local(2012, 3, 21).next_week(:wednesday)
+      assert_equal Time.local(2012, 3, 31), Time.local(2012, 3, 21).next_week(:saturday)
+      assert_equal Time.local(2012, 3, 27), Time.local(2012, 3, 21).next_week(:tuesday)
+      assert_equal Time.local(2012, 4, 02), Time.local(2012, 3, 21).next_week(:monday)
+    end
+  end
+
   def test_next_month_on_31st
     assert_equal date_time_init(2005,9,30,15,15,10), date_time_init(2005,8,31,15,15,10).next_month
   end
@@ -121,6 +130,15 @@ module DateAndTimeBehavior
     assert_equal date_time_init(2006,11,15,0,0,0), date_time_init(2006,11,23,0,0,0).prev_week(:wednesday)
   end
 
+  def test_prev_week_with_default_beginning_of_week
+    with_bw_default(:tuesday) do
+      assert_equal Time.local(2012, 3, 14), Time.local(2012, 3, 21).prev_week(:wednesday)
+      assert_equal Time.local(2012, 3, 17), Time.local(2012, 3, 21).prev_week(:saturday)
+      assert_equal Time.local(2012, 3, 13), Time.local(2012, 3, 21).prev_week(:tuesday)
+      assert_equal Time.local(2012, 3, 19), Time.local(2012, 3, 21).prev_week(:monday)
+    end
+  end
+
   def test_prev_month_on_31st
     assert_equal date_time_init(2004,2,29,10,10,10), date_time_init(2004,3,31,10,10,10).prev_month
   end
@@ -151,6 +169,18 @@ module DateAndTimeBehavior
     assert_equal 3, date_time_init(2011,11,9,0,0,0).days_to_week_start(:sunday)
   end
 
+  def test_days_to_week_start_with_default_set
+    with_bw_default(:friday) do
+      assert_equal 6, Time.local(2012,03,8,0,0,0).days_to_week_start
+      assert_equal 5, Time.local(2012,03,7,0,0,0).days_to_week_start
+      assert_equal 4, Time.local(2012,03,6,0,0,0).days_to_week_start
+      assert_equal 3, Time.local(2012,03,5,0,0,0).days_to_week_start
+      assert_equal 2, Time.local(2012,03,4,0,0,0).days_to_week_start
+      assert_equal 1, Time.local(2012,03,3,0,0,0).days_to_week_start
+      assert_equal 0, Time.local(2012,03,2,0,0,0).days_to_week_start
+    end
+  end
+
   def test_beginning_of_week
     assert_equal date_time_init(2005,1,31,0,0,0),  date_time_init(2005,2,4,10,10,10).beginning_of_week
     assert_equal date_time_init(2005,11,28,0,0,0), date_time_init(2005,11,28,0,0,0).beginning_of_week #monday
@@ -183,4 +213,24 @@ module DateAndTimeBehavior
     assert_equal date_time_init(2007,12,31,23,59,59,Rational(999999999, 1000)), date_time_init(2007,2,22,10,10,10).end_of_year
     assert_equal date_time_init(2007,12,31,23,59,59,Rational(999999999, 1000)), date_time_init(2007,12,31,10,10,10).end_of_year
   end
+
+  def test_monday_with_default_beginning_of_week_set
+    with_bw_default(:saturday) do
+      assert_equal date_time_init(2012,9,17,0,0,0), date_time_init(2012,9,18,0,0,0).monday
+    end
+  end
+
+  def test_sunday_with_default_beginning_of_week_set
+    with_bw_default(:wednesday) do
+      assert_equal date_time_init(2012,9,23,23,59,59, Rational(999999999, 1000)), date_time_init(2012,9,19,0,0,0).sunday
+    end
+  end
+
+  def with_bw_default(bw = :monday)
+    old_bw = Date.beginning_of_week
+    Date.beginning_of_week = bw
+    yield
+  ensure
+    Date.beginning_of_week = old_bw
+  end
 end