Add support for "ww" in date format (#12037)

Calculate number of the week in the year based on Date. Note, support for "ww" is missing from GWT DateTimeFormat and java.util.Calendar is not supported in GWT, hence DIY method is needed.

Fixes: #10603

client/src/main/java/com/vaadin/client/DateTimeService.java

@@ -39,6 +39,10 @@ public class DateTimeService {
 
     private static int[] maxDaysInMonth = { 31, 28, 31, 30, 31, 30, 31, 31, 30,
             31, 30, 31 };
+    private int[] yearDays = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273,
+            304, 334 };
+    private int[] leapYearDays = { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274,
+            305, 335};
 
     private static final long MILLISECONDS_PER_DAY = 24 * 3600 * 1000;
 
@@ -372,6 +376,10 @@ public class DateTimeService {
      * @since 8.2
      */
     public String formatDate(Date date, String formatStr, TimeZone timeZone) {
+        /*
+         * Format week numbers
+         */
+        formatStr = formatWeekNumbers(date, formatStr);
         /*
          * Format month and day names separately when locale for the
          * DateTimeService is not the same as the browser locale
@@ -388,6 +396,47 @@ public class DateTimeService {
         return result;
     }
 
+    /*
+     * Calculate number of the week in the year based on Date
+     * Note, support for "ww" is missing GWT DateTimeFormat
+     * and java.util.Calendar is not supported in GWT
+     * Hence DIY method needed
+     */
+    private String getWeek(Date date) {
+        int year = date.getYear()+1900;
+        int month = date.getMonth();
+        int day = date.getDate()+1;
+        int weekDay = date.getDay();
+        if (weekDay == 6) { 
+            weekDay = 0;
+        } else {
+           weekDay = weekDay - 1;
+        }
+        boolean leap = false;
+        if (((year % 4) == 0) && (((year % 100) != 0) || ((year % 400) == 0))) {
+           leap = true;
+        }
+        int week;
+        if (leap) {
+            week = countWeek(leapYearDays, month, day, weekDay);
+        } else {
+            week = countWeek(yearDays, month, day, weekDay);
+        }
+        return ""+week;
+    }
+
+    private int countWeek(int[] days, int month, int day, int weekDay) {
+        return ((days[month] + day) - (weekDay + 7) % 7 + 7) / 7;
+    }
+
+    private String formatWeekNumbers(Date date, String formatStr) {
+        if (formatStr.contains("ww")) {
+            String weekNumber = getWeek(date);
+            formatStr = formatStr.replaceAll("ww", weekNumber);
+        }
+        return formatStr;
+    }
+
     private String formatDayNames(Date date, String formatStr) {
         if (formatStr.contains("EEEE")) {
             String dayName = getDay(date.getDay());

server/src/main/java/com/vaadin/ui/AbstractLocalDateField.java

@@ -15,9 +15,11 @@
  */
 package com.vaadin.ui;
 
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
 import java.time.Instant;
 import java.time.LocalDate;
-import java.time.LocalDateTime;
+import java.time.ZoneId;
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
 import java.time.format.FormatStyle;
@@ -26,6 +28,7 @@ import java.util.Date;
 import java.util.Locale;
 import java.util.Map;
 
+import com.vaadin.data.Result;
 import com.vaadin.data.validator.DateRangeValidator;
 import com.vaadin.data.validator.RangeValidator;
 import com.vaadin.shared.ui.datefield.AbstractTextualDateFieldState;
@@ -163,4 +166,27 @@ public abstract class AbstractLocalDateField
         return temporalAccessor == null ? null
                 : LocalDate.from(temporalAccessor);
     }
+
+    @Override
+    protected Result<LocalDate> handleUnparsableDateString(String dateString) {
+        // Handle possible week number, which cannot be parsed client side due
+        // limitations in GWT
+        if (this.getDateFormat() != null && this.getDateFormat().contains("w")) {
+            Date parsedDate;
+            SimpleDateFormat df = new SimpleDateFormat(this.getDateFormat(),this.getLocale());
+            try {
+                parsedDate = df.parse(dateString);
+            } catch (ParseException e) {
+                return super.handleUnparsableDateString(dateString);
+            }
+            ZoneId zi = this.getZoneId();
+            if (zi ==  null) {
+                zi = ZoneId.systemDefault();
+            }
+            LocalDate date = Instant.ofEpochMilli(parsedDate.getTime()).atZone(zi).toLocalDate();
+            return Result.ok(date);
+        } else {
+            return super.handleUnparsableDateString(dateString);
+        }
+    }
 }

uitest/src/main/java/com/vaadin/tests/components/datefield/AbstractDateFieldTest.java

@@ -64,6 +64,7 @@ public abstract class AbstractDateFieldTest<T extends AbstractLocalDateField>
                 getDatePattern(new Locale("fi", "FI"), DateFormat.MEDIUM));
         options.put(getDatePattern(new Locale("fi", "FI"), DateFormat.SHORT),
                 getDatePattern(new Locale("fi", "FI"), DateFormat.SHORT));
+        options.put("ww yyyy", "ww yyyy");
 
         createSelectAction("Date format", category, options, "-",
                 dateFormatCommand);