Add support for skeleton date formats

lib/ffi-icu/lib.rb

@@ -425,11 +425,12 @@ module ICU
     attach_function :unum_set_attribute, "unum_setAttribute#{suffix}", [:pointer, :number_format_attribute, :int32_t], :void
     # date
     enum :date_format_style, [
-      :none,  -1,
-      :full,   0,
-      :long,   1,
-      :medium, 2,
-      :short,  3,
+      :pattern, -2,
+      :none,    -1,
+      :full,    0,
+      :long,    1,
+      :medium,  2,
+      :short,   3,
     ]
     attach_function :udat_open, "udat_open#{suffix}", [:date_format_style, :date_format_style, :string, :pointer, :int32_t, :pointer, :int32_t, :pointer ], :pointer
     attach_function :udat_close, "unum_close#{suffix}", [:pointer], :void
@@ -437,6 +438,9 @@ module ICU
     attach_function :udat_parse, "udat_parse#{suffix}", [:pointer, :pointer, :int32_t,  :pointer, :pointer], :double
     attach_function :udat_toPattern, "udat_toPattern#{suffix}", [:pointer, :bool    , :pointer, :int32_t    , :pointer], :int32_t
     attach_function :udat_applyPattern, "udat_applyPattern#{suffix}", [:pointer, :bool    , :pointer, :int32_t     ], :void
+    # skeleton pattern
+    attach_function :udatpg_open, "udatpg_open#{suffix}", [:string, :pointer], :pointer
+    attach_function :udatpg_getBestPattern, "udatpg_getBestPattern#{suffix}", [:pointer, :pointer, :int32_t, :pointer, :int32_t, :pointer], :int32_t
     # tz
     attach_function :ucal_setDefaultTimeZone, "ucal_setDefaultTimeZone#{suffix}", [:pointer, :pointer], :int32_t
     attach_function :ucal_getDefaultTimeZone, "ucal_getDefaultTimeZone#{suffix}", [:pointer, :int32_t, :pointer], :int32_t

lib/ffi-icu/time_formatting.rb

@@ -65,21 +65,46 @@ module ICU
 
       private
 
-      def make_formatter(time_style, date_style, locale, time_zone_str)
+      def make_formatter(time_style, date_style, locale, time_zone_str, skeleton)
         time_zone = nil
-        d_len = 0
+        tz_len = 0
         if time_zone_str
           time_zone = UCharPointer.from_string(time_zone_str)
-          d_len = time_zone_str.size
+          tz_len = time_zone_str.size
         else
           Lib.check_error { | error| 
             i_len  = 150
             time_zone = UCharPointer.new(i_len)
-            d_len = Lib.ucal_getDefaultTimeZone(time_zone, i_len, error) 
+            tz_len = Lib.ucal_getDefaultTimeZone(time_zone, i_len, error) 
           }
         end
 
-        ptr = Lib.check_error { | error| Lib.udat_open(time_style, date_style, locale, time_zone, d_len, FFI::MemoryPointer.new(4), -1, error) }
+        pattern_len = -1
+        pattern_ptr = FFI::MemoryPointer.new(4)
+
+        if skeleton
+          skeleton = UCharPointer.from_string(skeleton)
+
+          pattern_len = 0
+          pattern_ptr = UCharPointer.new(pattern_len)
+
+          pg_ptr = Lib.check_error { |error| Lib.udatpg_open(locale, error) }
+          generator = FFI::AutoPointer.new(pg_ptr, Lib.method(:udat_close))
+
+          retried = false  
+          begin
+            Lib.check_error do |error|
+              pattern_len = Lib.udatpg_getBestPattern(generator, skeleton, skeleton.size, pattern_ptr, pattern_len, error)
+            end
+          rescue BufferOverflowError
+            raise BufferOverflowError, "needed: #{pattern_len}" if retried
+            pattern_ptr = pattern_ptr.resized_to pattern_len
+            retried = true
+            retry
+          end
+        end
+
+        ptr = Lib.check_error { | error| Lib.udat_open(time_style, date_style, locale, time_zone, tz_len, pattern_ptr, pattern_len, error) }
         FFI::AutoPointer.new(ptr, Lib.method(:udat_close))
       end
     end
@@ -91,7 +116,9 @@ module ICU
         locale     = options[:locale] || 'C'
         tz_style   = options[:tz_style]
         time_zone  = options[:zone]
-        @f = make_formatter(time_style, date_style, locale, time_zone)
+        skeleton   = options[:skeleton]
+
+        @f = make_formatter(time_style, date_style, locale, time_zone, skeleton)
         if tz_style
           f0 = date_format(true)
           f1 = update_tz_format(f0, tz_style)    
@@ -177,6 +204,23 @@ module ICU
           needed_length = Lib.udat_applyPattern(@f, localized, pattern, pattern_len)
         end
       end
+
+      def with_retry(out_ptr)
+        needed_length = 0
+        out_ptr = UCharPointer.new(needed_length)
+        retried = false
+
+        begin
+          Lib.check_error do |error|
+            yield(error)
+          end
+        rescue BufferOverflowError
+          raise BufferOverflowError, "needed: #{needed_length}" if retried
+          out_ptr = out_ptr.resized_to needed_length
+          retried = true
+          retry
+        end
+      end
     end # DateTimeFormatter
   end # Formatting
 end # ICU

spec/time_spec.rb

@@ -59,7 +59,7 @@ module ICU
         expect(f2.format(t8)).to eq("3/29/08#{en_sep} 6:38:24 AM #{en_tz}")
       end
 
-      f3 = TimeFormatting.create(:locale => 'de_DE', :zone => 'Africa/Dakar ', :date => :short , :time => :long)
+      f3 = TimeFormatting.create(:locale => 'de_DE', :zone => 'Africa/Dakar', :date => :short , :time => :long)
       ge_sep = ""
       if cldr_version >= "27.0.1"
         ge_sep = ","
@@ -82,6 +82,19 @@ module ICU
         expect(f3.format(t7)).to eq("29.03.08#{ge_sep} 02:37:23 GMT")
         expect(f3.format(t8)).to eq("29.03.08#{ge_sep} 03:38:24 GMT")
       end
+
+      context 'skeleton pattern' do
+        f4 = TimeFormatting.create(:locale => 'fr_FR', :date => :pattern , :time => :pattern, :skeleton => 'MMMy')
+
+        it 'check format' do
+          expect(f4.format(t0)).to eq("nov. 2008")
+          expect(f4.format(t1)).to eq("oct. 2008")
+        end
+
+        it 'check date_format' do
+          expect(f4.date_format(true)).to eq("MMM y")
+        end
+      end
     end
   end
 end