Add :day_format option to date_select

  date_select("article", "written_on", day_format: ->(day) { day.ordinalize })

generates day options like

  <option value="1">1st</option>\n<option value="2">2nd</option>...

Author: shunichi

actionview/CHANGELOG.md

@@ -1,3 +1,10 @@
+*   Add `:day_format` option to `date_select`
+
+        date_select("article", "written_on", day_format: ->(day) { day.ordinalize })
+        # generates day options like <option value="1">1st</option>\n<option value="2">2nd</option>...
+
+    *Shunichi Ikegami*
+
 *   Allow `link_to` helper to infer link name from `Model#to_s` when it
     is used with a single argument:
 

actionview/lib/action_view/helpers/date_helper.rb

@@ -206,6 +206,7 @@ def time_ago_in_words(from_time, options = {})
       #   you are creating new record. While editing existing record, <tt>:end_year</tt> defaults to
       #   the current selected year plus 5.
       # * <tt>:year_format</tt>       - Set format of years for year select. Lambda should be passed.
+      # * <tt>:day_format</tt>        - Set format of days for day select. Lambda should be passed.
       # * <tt>:discard_day</tt>       - Set to true if you don't want to show a day select. This includes the day
       #   as a hidden field instead of showing a select field. Also note that this implicitly sets the day to be the
       #   first of the given month in order to not create invalid dates like 31 February.
@@ -279,6 +280,9 @@ def time_ago_in_words(from_time, options = {})
       #   # Generates a date select with custom year format.
       #   date_select("article", "written_on", year_format: ->(year) { "Heisei #{year - 1988}" })
       #
+      #   # Generates a date select with custom day format.
+      #   date_select("article", "written_on", day_format: ->(day) { day.ordinalize })
+      #
       # The selects are prepared for multi-parameter assignment to an Active Record object.
       #
       # Note: If the day is not included as an option but the month is, the day will be set to the 1st to ensure that
@@ -811,7 +815,7 @@ def select_day
         if @options[:use_hidden] || @options[:discard_day]
           build_hidden(:day, day || 1)
         else
-          build_options_and_select(:day, day, start: 1, end: 31, leading_zeros: false, use_two_digit_numbers: @options[:use_two_digit_numbers])
+          build_select(:day, build_day_options(day))
         end
       end
 
@@ -899,6 +903,27 @@ def translated_month_names
           I18n.translate(key, locale: @options[:locale])
         end
 
+        # Looks up day names by number.
+        #
+        #   day_name(1) # => 1
+        #
+        # If the <tt>use_two_digit_numbers: true</tt> option is passed to DateTimeSelector:
+        #
+        #   day_name(1) # => "01"
+        #
+        # If the <tt>day_format: ->(day) { day.ordinalize }</tt> option is passed to DateTimeSelector:
+        #
+        #   day_name(1) # => "1st"
+        def day_name(number)
+          if day_format_lambda = @options[:day_format]
+            day_format_lambda.call(number)
+          elsif @options[:use_two_digit_numbers]
+            "%02d" % number
+          else
+            number
+          end
+        end
+
         # Looks up month names by number (1-based):
         #
         #   month_name(1) # => "January"
@@ -1011,6 +1036,35 @@ def build_options(selected, options = {})
           (select_options.join("\n") + "\n").html_safe
         end
 
+        # Build select option HTML for day.
+        #  build_day_options(2)
+        #  => "<option value="1">1</option>
+        #      <option value="2" selected="selected">2</option>
+        #      <option value="3">3</option>..."
+        #
+        # If <tt>day_format: ->(day) { day.ordinalize }</tt> option is passed to DateTimeSelector
+        #  build_day_options(2)
+        #  => "<option value="1">1st</option>
+        #      <option value="2" selected="selected">2nd</option>
+        #      <option value="3">3rd</option>..."
+        #
+        # If <tt>use_two_digit_numbers: true</tt> option is passed to DateTimeSelector
+        #  build_day_options(2)
+        #  => "<option value="1">01</option>
+        #      <option value="2" selected="selected">02</option>
+        #      <option value="3">03</option>..."
+        def build_day_options(selected)
+          select_options = []
+          (1..31).each do |value|
+            tag_options = { value: value }
+            tag_options[:selected] = "selected" if selected == value
+            text = day_name(value)
+            select_options << content_tag("option", text, tag_options)
+          end
+
+          (select_options.join("\n") + "\n").html_safe
+        end
+
         # Build select option HTML for year.
         # If <tt>year_format</tt> option is not passed
         #  build_year_options(1998, start: 1998, end: 2000)

actionview/test/template/date_helper_test.rb

@@ -251,6 +251,16 @@ def test_select_day_with_two_digit_numbers
     assert_dom_equal expected, select_day(2, use_two_digit_numbers: true)
   end
 
+  def test_select_day_with_day_fomat
+    expected = +%(<select id="date_day" name="date[day]">\n)
+    expected << %(<option value="1">1st</option>\n<option selected="selected" value="2">2nd</option>\n<option value="3">3rd</option>\n<option value="4">4th</option>\n<option value="5">5th</option>\n<option value="6">6th</option>\n<option value="7">7th</option>\n<option value="8">8th</option>\n<option value="9">9th</option>\n<option value="10">10th</option>\n<option value="11">11th</option>\n<option value="12">12th</option>\n<option value="13">13th</option>\n<option value="14">14th</option>\n<option value="15">15th</option>\n<option value="16">16th</option>\n<option value="17">17th</option>\n<option value="18">18th</option>\n<option value="19">19th</option>\n<option value="20">20th</option>\n<option value="21">21st</option>\n<option value="22">22nd</option>\n<option value="23">23rd</option>\n<option value="24">24th</option>\n<option value="25">25th</option>\n<option value="26">26th</option>\n<option value="27">27th</option>\n<option value="28">28th</option>\n<option value="29">29th</option>\n<option value="30">30th</option>\n<option value="31">31st</option>\n)
+    expected << "</select>\n"
+
+    day_format = ->(day) { ActiveSupport::Inflector.ordinalize(day) }
+    assert_dom_equal expected, select_day(Time.mktime(2011, 8, 2), day_format: day_format)
+    assert_dom_equal expected, select_day(2, day_format: day_format)
+  end
+
   def test_select_day_with_html_options
     expected = +%(<select id="date_day" name="date[day]" class="selector">\n)
     expected << %(<option value="1">1</option>\n<option value="2">2</option>\n<option value="3">3</option>\n<option value="4">4</option>\n<option value="5">5</option>\n<option value="6">6</option>\n<option value="7">7</option>\n<option value="8">8</option>\n<option value="9">9</option>\n<option value="10">10</option>\n<option value="11">11</option>\n<option value="12">12</option>\n<option value="13">13</option>\n<option value="14">14</option>\n<option value="15">15</option>\n<option value="16" selected="selected">16</option>\n<option value="17">17</option>\n<option value="18">18</option>\n<option value="19">19</option>\n<option value="20">20</option>\n<option value="21">21</option>\n<option value="22">22</option>\n<option value="23">23</option>\n<option value="24">24</option>\n<option value="25">25</option>\n<option value="26">26</option>\n<option value="27">27</option>\n<option value="28">28</option>\n<option value="29">29</option>\n<option value="30">30</option>\n<option value="31">31</option>\n)