Show Week Numbers

README.md

@@ -52,6 +52,7 @@ Possible options are:
 * :first_day_of_week: The first day of the week (0 = Sunday, 1 = Monday etc.). Defaults to the :'date.first_day_of_week' translation in the respective locale or 0 if no translation can be found.
 * :hide_day_names: Hide the table header showing day names. Defaults to false.
 * :hide_month_name: Hide the table header showing the month name. Defaults to false.
+* :show_week_numbers: Shows the week numbers on the left of the calendar. Defaults to false. Week numbers are calculated considering Monday as the first day of week except if the :first_day_of_week is set to 0 (Sunday).
 * :use_full_day_names: Use full instead of abbreviated day names. Defaults to false.
 * :use_full_month_names: Use full instead of abbreviated month names. Defaults to true.
 * :yield_surrounding_days: Defines whether or not days or the previous and next month are yielded to the passed block. Defaults to false.
@@ -124,6 +125,8 @@ You can do all kinds of mighty stuff with a proc. Imagine a situation where you
 
 The option :next_and_previous_month can be used as a shortcut if you want to use the same formatting for the next and previous month. Both, :next_month and :previous_month override the :next_and_previous_month if given.
 
+An alternative description for the week header can be provided by using the option :weeks_column_name. This defaults to "Week".
+
 i18n
 ====
 

lib/later_dude/calendar.rb

@@ -39,7 +39,7 @@ def initialize(year, month, options={}, &block)
     def to_html(&block)
       @block = block if block_given?
       content_tag(:table, :class => "#{@options[:calendar_class]}") do
-        content_tag(:thead, "#{show_month_names}#{show_day_names}".html_safe) + content_tag(:tbody, show_days)
+        content_tag(:thead, "#{show_week_headers}#{show_month_names}#{show_day_names}".html_safe) + content_tag(:tbody, show_days)
       end
     end
 
@@ -53,7 +53,7 @@ def last_rendered_date
 
     private
     def show_days
-      content_tag(:tr, "#{show_previous_month}#{show_current_month}#{show_following_month}".html_safe)
+      content_tag(:tr, "#{show_week_number}#{show_previous_month}#{show_current_month}#{show_following_month}".html_safe)
     end
 
     def show_previous_month
@@ -99,12 +99,26 @@ def show_day(day)
 
       content = content_tag(:td, content.to_s.html_safe, options)
 
-      # close table row at the end of a week and start a new one
-      # opening and closing tag for the first and last week are included in #show_days
-      content << "</tr><tr>".html_safe if day < @days.last && day.wday == last_day_of_week
+      if day < @days.last && day.wday == last_day_of_week
+        # close table row at the end of a week and start a new one
+        # opening and closing tag for the first and last week are included in #show_days
+        content << "</tr><tr>".html_safe
+        # add week number at the beginning of next row
+        content << show_week_number(day.next)
+      end
       content
     end
 
+    # if the day argument is not passed then we are showing the first week
+    def show_week_number(day = @days.first)
+      return if !@options[:show_week_numbers]
+
+      # this considers only weeks starting on sunday or monday
+      # todo: week number calculation for all other scenarios
+      week = @options[:first_day_of_week] == 0 ? (day+1).cweek : day.cweek
+      content_tag(:th, week, :scope => "row", :class => "week_number")
+    end
+
     def beginning_of_week(day)
       diff = day.wday - first_day_of_week
       diff += 7 if first_day_of_week > day.wday # hackish ;-)
@@ -117,6 +131,18 @@ def show_month_names
       content_tag(:tr, "#{previous_month}#{current_month}#{next_month}".html_safe, :class => 'month_names')
     end
 
+    def show_week_headers
+      return if !@options[:show_week_numbers]
+      rows = 3
+      rows -= 1 if @options[:hide_month_name]
+      rows -= 1 if @options[:hide_day_names]
+
+      content_tag(:tr, :class => "week_header") do
+        content_tag(:th, @options[:weeks_column_name].html_safe, :scope => "col", :rowspan => rows, :class => "week") +
+        content_tag(:th, "", :colspan => "7")
+      end
+    end
+
     # @options[:previous_month] can either be a single value or an array containing two values. For a single value, the
     # value can either be a strftime compatible string or a proc.
     # For an array, the first value is considered to be a strftime compatible string and the second is considered to be
@@ -207,6 +233,8 @@ def default_calendar_options
           :first_day_of_week => I18n.translate(:'date.first_day_of_week', :default => "0").to_i,
           :hide_day_names => false,
           :hide_month_name => false,
+          :show_week_numbers => false,
+          :weeks_column_name => "Week",
           :use_full_day_names => false,
           :current_month => I18n.translate(:'date.formats.calendar_header', :default => "%B"),
           :next_month => false,

test/test_helper.rb

@@ -1,5 +1,6 @@
 require 'test/unit'
 require 'active_support/test_case'
+require 'active_support/core_ext'
 require 'mocha'
 
 require 'later_dude'