Patch from Johan Karlsteen for bug #53966 - Implement IfError AP function

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1426382 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java

@@ -22,8 +22,7 @@ import org.apache.poi.ss.formula.udf.UDFFinder;
 import java.util.*;
 
 /**
- * @author Josh Micich
+ * Analysis Toolpack Function Definitions 
- * @author Petr Udalau - systematized work of add-in libraries and user defined functions.
  */
 public final class AnalysisToolPak implements UDFFinder {
 
@@ -112,7 +111,7 @@ public final class AnalysisToolPak implements UDFFinder {
         r(m, "HEX2BIN", null);
         r(m, "HEX2DEC", null);
         r(m, "HEX2OCT", null);
-        r(m, "IFERROR", null);
+        r(m, "IFERROR", IfError.instance);
         r(m, "IMABS", null);
         r(m, "IMAGINARY", null);
         r(m, "IMARGUMENT", null);

src/java/org/apache/poi/ss/formula/atp/IfError.java

@@ -0,0 +1,65 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.atp;
+
+import org.apache.poi.ss.formula.OperationEvaluationContext;
+import org.apache.poi.ss.formula.eval.ErrorEval;
+import org.apache.poi.ss.formula.eval.EvaluationException;
+import org.apache.poi.ss.formula.eval.ValueEval;
+import org.apache.poi.ss.formula.functions.FreeRefFunction;
+/**
+ * Implementation of 'Analysis Toolpak' Excel function IFERROR()<br/>
+ *
+ * Returns an error text if there is an error in the evaluation<p/>
+ * 
+ * <b>Syntax</b><br/>
+ * <b>IFERROR</b>(<b>expression</b>, <b>string</b>)
+ * 
+ * @author Johan Karlsteen
+ */
+final class IfError implements FreeRefFunction {
+
+	public static final FreeRefFunction instance = new IfError();
+
+	private IfError() {
+		// enforce singleton
+	}
+
+	public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
+		if (args.length != 2) {
+			return ErrorEval.VALUE_INVALID;
+		}
+
+		ValueEval val;
+		try {
+			val = evaluateArgParity(args[0], args[1], ec.getRowIndex(), ec.getColumnIndex());
+		} catch (EvaluationException e) {
+			return e.getErrorEval();
+		}
+
+		return val;
+	}
+
+	private static ValueEval evaluateArgParity(ValueEval arg, ValueEval iferror, int srcCellRow, int srcCellCol) throws EvaluationException {
+		if(arg instanceof ErrorEval) {
+			return iferror;
+		} else {
+			return arg;
+		}
+	}
+}

src/testcases/org/apache/poi/ss/formula/atp/TestIfError.java

@@ -0,0 +1,84 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+package org.apache.poi.ss.formula.atp;
+
+import junit.framework.TestCase;
+
+import org.apache.poi.hssf.usermodel.HSSFWorkbook;
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.FormulaEvaluator;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.ss.util.CellReference;
+
+/**
+ * Testcase for 'Analysis Toolpak' function IFERROR()
+ * 
+ * @author Johan Karlsteen
+ */
+public class TestIfError extends TestCase {
+
+    /**
+     * =IFERROR(210/35,\"Error in calculation\")"  Divides 210 by 35 and returns 6.0
+     * =IFERROR(55/0,\"Error in calculation\")"    Divides 55 by 0 and returns the error text
+     */
+    public static void testEvaluate(){
+        Workbook wb = new HSSFWorkbook();
+        Sheet sh = wb.createSheet();
+        Row row1 = sh.createRow(0);
+        Row row2 = sh.createRow(1);
+
+        // Create cells
+        row1.createCell(0, Cell.CELL_TYPE_NUMERIC);
+        row1.createCell(1, Cell.CELL_TYPE_NUMERIC);
+        row2.createCell(0, Cell.CELL_TYPE_NUMERIC);
+        row2.createCell(1, Cell.CELL_TYPE_NUMERIC);
+
+        // Create references
+        CellReference a1 = new CellReference("A1");
+        CellReference a2 = new CellReference("A2");
+        CellReference b1 = new CellReference("B1");
+        CellReference b2 = new CellReference("B2");
+        
+        // Set values
+        sh.getRow(a1.getRow()).getCell(a1.getCol()).setCellValue(210);
+        sh.getRow(a2.getRow()).getCell(a2.getCol()).setCellValue(55);
+        sh.getRow(b1.getRow()).getCell(b1.getCol()).setCellValue(35);
+        sh.getRow(b2.getRow()).getCell(b2.getCol()).setCellValue(0);
+        
+        Cell cell1 = sh.createRow(3).createCell(0);
+        cell1.setCellFormula("IFERROR(A1/B1,\"Error in calculation\")");
+        Cell cell2 = sh.createRow(3).createCell(0);
+        cell2.setCellFormula("IFERROR(A2/B2,\"Error in calculation\")");
+
+        double accuracy = 1E-9;
+
+        FormulaEvaluator evaluator = wb.getCreationHelper().createFormulaEvaluator();
+
+        assertEquals("Checks that the cell is numeric",
+        		Cell.CELL_TYPE_NUMERIC, evaluator.evaluate(cell1).getCellType());
+        assertEquals("Divides 210 by 35 and returns 6.0",
+                6.0, evaluator.evaluate(cell1).getNumberValue(), accuracy);
+        
+        
+        assertEquals("Checks that the cell is numeric",
+        		Cell.CELL_TYPE_STRING, evaluator.evaluate(cell2).getCellType());        
+        assertEquals("Rounds -10 to a nearest multiple of -3 (-9)",
+                "Error in calculation", evaluator.evaluate(cell2).getStringValue());
+    }
+}