Added: toDate() now supports formats.

My dataset has the same dates written in two styles: Nov-09 and 11/09
You can now parse this using: value.toDate2('MM/yy','MMM-yy').toString('yyyy-MM')



git-svn-id: http://google-refine.googlecode.com/svn/trunk@414 7d457c2a-affb-35e4-300a-418c747d4874

src/main/java/com/metaweb/gridworks/expr/functions/ToDate.java

@@ -5,6 +5,10 @@ import java.util.Properties;
 import org.json.JSONException;
 import org.json.JSONWriter;
 
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.GregorianCalendar;
+
 import com.metaweb.gridworks.expr.util.CalendarParser;
 import com.metaweb.gridworks.expr.util.CalendarParserException;
 import com.metaweb.gridworks.gel.Function;
@@ -12,23 +16,51 @@ import com.metaweb.gridworks.gel.Function;
 public class ToDate implements Function {
 
     public Object call(Properties bindings, Object[] args) {
-        if (args.length == 1 || args.length == 2) {
+        if (args.length == 0) {
-            Object o1 = args[0];
+            // missing value, can this happen?
-            if (o1 != null && o1 instanceof String) {
+        }
+        if (!(args[0] instanceof String)) {
+            // ignore cell values that aren't strings
+            return null;
+        }
+        String o1 = (String) args[0];
+
+        // "o, boolean month_first (optional)"
+        if (args.length == 1 || (args.length == 2 && args[1] instanceof Boolean)) {
             boolean month_first = true;
             if (args.length == 2) {
-                    Object o2 = args[1];
+                month_first = (Boolean) args[1];
-                    if (o2 != null && o2 instanceof Boolean) {
-                        month_first = ((Boolean) o2).booleanValue();
-                    }
             }
             try {
-                    return CalendarParser.parse((String) o1, (month_first) ? CalendarParser.MM_DD_YY : CalendarParser.DD_MM_YY);
+                return CalendarParser.parse( o1, (month_first) ? CalendarParser.MM_DD_YY : CalendarParser.DD_MM_YY);
             } catch (CalendarParserException e) {
                 // do something about 
             }
         }
+
+        // "o, format1, format2 (optional), ..."
+        if (args.length>=2) {
+            for (int i=1;i<args.length;i++) {
+                if (!(args[i] instanceof String)) {
+                    // skip formats that aren't strings
+                    continue;
                 }
+                String format  = (String) args[i];
+                SimpleDateFormat formatter = new SimpleDateFormat(format);
+                Date date = null;
+                try {
+                    date = formatter.parse(o1);
+                } catch (java.text.ParseException e) {
+                    // ignore
+                }
+                if (date != null) {
+                    GregorianCalendar c = new GregorianCalendar();
+                    c.setTime(date);
+                    return c;
+                }
+            }
+        }
+
         return null;
     }
 
@@ -37,8 +69,8 @@ public class ToDate implements Function {
     throws JSONException {
 
         writer.object();
-        writer.key("description"); writer.value("Returns o converted to a date object");
+        writer.key("description"); writer.value("Returns o converted to a date object, you can hint if the day or the month is listed first, or give an ordered list of possible formats using this syntax: http://java.sun.com/j2se/1.4.2/docs/api/java/text/SimpleDateFormat.html");
-        writer.key("params"); writer.value("o, boolean month_first (optional)");
+        writer.key("params"); writer.value("o, boolean month_first / format1, format2, ... (all optional)");
         writer.key("returns"); writer.value("date");
         writer.endObject();
     }