Fix bug #52349 - Correctly support excel style date format strings in the TEXT function

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1221123 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/status.xml

@@ -34,6 +34,7 @@
 
     <changes>
         <release version="3.8-beta6" date="2012-??-??">
+           <action dev="poi-developers" type="fix">52349 - Correctly support excel style date format strings in the TEXT function</action>
            <action dev="poi-developers" type="fix">52369 - XSSFExcelExtractor should format numeric cells based on the format strings applied to them</action>
            <action dev="poi-developers" type="fix">52369 - Event based XSSF parsing should handle formatting of formula values in XSSFSheetXMLHandler</action>
            <action dev="poi-developers" type="fix">52348 - Avoid exception when creating cell style in a workbook that has an empty xf table</action>

src/java/org/apache/poi/ss/formula/functions/TextFunction.java

@@ -30,6 +30,7 @@ import org.apache.poi.ss.formula.eval.NumberEval;
 import org.apache.poi.ss.formula.eval.OperandResolver;
 import org.apache.poi.ss.formula.eval.StringEval;
 import org.apache.poi.ss.formula.eval.ValueEval;
+import org.apache.poi.ss.usermodel.DataFormatter;
 
 /**
  * @author Amol S. Deshmukh < amolweb at ya hoo dot com >
@@ -37,7 +38,7 @@ import org.apache.poi.ss.formula.eval.ValueEval;
  * @author Stephen Wolke (smwolke at geistig.com)
  */
 public abstract class TextFunction implements Function {
-
+	protected static final DataFormatter formatter = new DataFormatter();
    protected static final String EMPTY_STRING = "";
 
 	protected static final String evaluateStringArg(ValueEval eval, int srcRow, int srcCol) throws EvaluationException {
@@ -281,8 +282,11 @@ public abstract class TextFunction implements Function {
 	 * TEXT returns a number value formatted with the given
 	 * number formatting string. This function is not a complete implementation of
 	 * the Excel function.  This function implements decimal formatting
-	 * with the Java class DecimalFormat.  For date formatting this function uses
+	 * with the Java class DecimalFormat.  For date formatting, this function uses
-	 * the SimpleDateFormat class.<p/>
+	 * {@link DataFormatter}, which attempts to replicate the Excel date 
+	 * format string.
+	 * 
+	 * TODO Merge much of this logic with {@link DataFormatter}
 	 *
 	 * <b>Syntax<b>:<br/> <b>TEXT</b>(<b>value</b>, <b>format_text</b>)<br/>
 	 *
@@ -343,12 +347,9 @@ public abstract class TextFunction implements Function {
 				}
 			} else {
 				try {
-					DateFormat dateFormatter = new SimpleDateFormat(s1);
+	            // Ask DataFormatter to handle the Date string for us
-					Calendar cal = new GregorianCalendar(1899, 11, 30, 0, 0, 0);
+				   String formattedDate = formatter.formatRawCellContents(s0, -1, s1);
-					cal.add(Calendar.DATE, (int)Math.floor(s0));
+					return new StringEval(formattedDate);
-					double dayFraction = s0 - Math.floor(s0);
-					cal.add(Calendar.MILLISECOND, (int) Math.round(dayFraction * 24 * 60 * 60 * 1000));
-					return new StringEval(dateFormatter.format(cal.getTime()));
 				} catch (Exception e) {
 					return ErrorEval.VALUE_INVALID;
 				}

src/testcases/org/apache/poi/ss/formula/functions/TestText.java

@@ -93,7 +93,7 @@ public final class TestText extends TestCase {
 	}
 
    public void testTextWithDateFormatSecondArg() {
-
+      // Test with Java style M=Month
       ValueEval numArg = new NumberEval(321.321);
       ValueEval formatArg = new StringEval("dd:MM:yyyy hh:mm:ss");
       ValueEval[] args = { numArg, formatArg };
@@ -101,13 +101,28 @@ public final class TestText extends TestCase {
       ValueEval testResult = new StringEval("16:11:1900 07:42:14");
       assertEquals(testResult.toString(), result.toString());
 
+      // Excel also supports "m before h is month"
+      formatArg = new StringEval("dd:mm:yyyy hh:mm:ss");
+      args[1] = formatArg;
+      result = T.TEXT.evaluate(args, -1, (short)-1);
+      testResult = new StringEval("16:11:1900 07:42:14");
+      assertEquals(testResult.toString(), result.toString());
+
       // this line is intended to compute how "November" would look like in the current locale
       String november = new SimpleDateFormat("MMMM").format(new GregorianCalendar(2010,10,15).getTime());
 
+      // Again with Java style
       formatArg = new StringEval("MMMM dd, yyyy");
       args[1] = formatArg;
       result = T.TEXT.evaluate(args, -1, (short)-1);
       testResult = new StringEval(november + " 16, 1900");
       assertEquals(testResult.toString(), result.toString());
+
+      // And Excel style
+      formatArg = new StringEval("mmmm dd, yyyy");
+      args[1] = formatArg;
+      result = T.TEXT.evaluate(args, -1, (short)-1);
+      testResult = new StringEval(november + " 16, 1900");
+      assertEquals(testResult.toString(), result.toString());
    }
 }