adding now() and inc() functions to the gel

git-svn-id: http://google-refine.googlecode.com/svn/trunk@202 7d457c2a-affb-35e4-300a-418c747d4874

src/main/java/com/metaweb/gridworks/expr/functions/date/Inc.java

@@ -0,0 +1,58 @@
+package com.metaweb.gridworks.expr.functions.date;
+
+import java.util.Calendar;
+import java.util.Properties;
+
+import org.json.JSONException;
+import org.json.JSONWriter;
+
+import com.metaweb.gridworks.expr.EvalError;
+import com.metaweb.gridworks.gel.ControlFunctionRegistry;
+import com.metaweb.gridworks.gel.Function;
+
+public class Inc implements Function {
+
+    public Object call(Properties bindings, Object[] args) {
+        if (args.length == 3 && 
+                args[0] != null && args[0] instanceof Calendar && 
+                args[1] != null && args[1] instanceof Number && 
+                args[2] != null && args[2] instanceof String) {
+            Calendar date = (Calendar) args[0];
+            int amount = ((Number) args[1]).intValue();
+            String unit = (String) args[2];
+            
+            date.add(getField(unit), amount);
+            
+            return date; 
+        }
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects a date, a number and a string");
+    }
+
+    private int getField(String unit) {
+        if ("hours".equals(unit) || "hour".equals(unit) || "h".equals(unit)) {
+            return Calendar.HOUR;
+        } else if ("days".equals(unit) || "day".equals(unit) || "d".equals(unit)) {
+            return Calendar.DAY_OF_MONTH;
+        } else if ("years".equals(unit) || "year".equals(unit)) {
+            return Calendar.YEAR;
+        } else if ("months".equals(unit) || "month".equals(unit)) { // avoid 'm' to avoid confusion with minute
+            return Calendar.MONTH;
+        } else if ("minutes".equals(unit) || "minute".equals(unit) || "min".equals(unit)) { // avoid 'm' to avoid confusion with month
+            return Calendar.MINUTE;
+        } else if ("weeks".equals(unit) || "week".equals(unit) || "w".equals(unit)) {
+            return Calendar.WEEK_OF_MONTH;
+        } else if ("seconds".equals(unit) || "sec".equals(unit) || "s".equals(unit)) {
+            return Calendar.SECOND;
+        } else {
+            throw new RuntimeException("Unit '" + unit + "' not recognized.");
+        }
+    }
+    
+    public void write(JSONWriter writer, Properties options) throws JSONException {
+        writer.object();
+        writer.key("description"); writer.value("Returns a date changed by the given amount in the given unit of time");
+        writer.key("params"); writer.value("date d, number value, string unit (default to 'hour')");
+        writer.key("returns"); writer.value("date");
+        writer.endObject();
+    }
+}

src/main/java/com/metaweb/gridworks/gel/ControlFunctionRegistry.java

@@ -17,6 +17,8 @@ import com.metaweb.gridworks.expr.functions.arrays.Sort;
 import com.metaweb.gridworks.expr.functions.booleans.And;
 import com.metaweb.gridworks.expr.functions.booleans.Not;
 import com.metaweb.gridworks.expr.functions.booleans.Or;
+import com.metaweb.gridworks.expr.functions.date.Inc;
+import com.metaweb.gridworks.expr.functions.date.Now;
 import com.metaweb.gridworks.expr.functions.math.Ceil;
 import com.metaweb.gridworks.expr.functions.math.Exp;
 import com.metaweb.gridworks.expr.functions.math.Floor;
@@ -145,6 +147,9 @@ public class ControlFunctionRegistry {
         registerFunction("reverse", new Reverse());
         registerFunction("sort", new Sort());
 
+        registerFunction("now", new Now());
+        registerFunction("inc", new Inc());
+        
         registerFunction("round", new Round());
         registerFunction("floor", new Floor());
         registerFunction("ceil", new Ceil());