001 /**
002 * ========================================
003 * JFreeReport : a free Java report library
004 * ========================================
005 *
006 * Project Info: http://reporting.pentaho.org/
007 *
008 * (C) Copyright 2000-2007, by Object Refinery Limited, Pentaho Corporation and Contributors.
009 *
010 * This library is free software; you can redistribute it and/or modify it under the terms
011 * of the GNU Lesser General Public License as published by the Free Software Foundation;
012 * either version 2.1 of the License, or (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016 * See the GNU Lesser General Public License for more details.
017 *
018 * You should have received a copy of the GNU Lesser General Public License along with this
019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020 * Boston, MA 02111-1307, USA.
021 *
022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023 * in the United States and other countries.]
024 *
025 * ------------
026 * $Id: AttrFunction.java,v 1.4 2007/04/01 18:49:25 taqua Exp $
027 * ------------
028 * (C) Copyright 2000-2005, by Object Refinery Limited.
029 * (C) Copyright 2005-2007, by Pentaho Corporation.
030 */
031
032 package org.jfree.report.expressions.formula.sys;
033
034 import org.jfree.formula.EvaluationException;
035 import org.jfree.formula.FormulaContext;
036 import org.jfree.formula.LibFormulaErrorValue;
037 import org.jfree.formula.function.Function;
038 import org.jfree.formula.function.ParameterCallback;
039 import org.jfree.formula.lvalues.TypeValuePair;
040 import org.jfree.formula.typing.coretypes.AnyType;
041 import org.jfree.formula.typing.coretypes.ErrorType;
042 import org.jfree.report.expressions.ReportFormulaContext;
043 import org.jfree.report.structure.Element;
044
045 /**
046 * Creation-Date: 24.11.2006, 13:02:41
047 *
048 * @author Thomas Morgner
049 */
050 public class AttrFunction implements Function
051 {
052 public AttrFunction()
053 {
054 }
055
056 public String getCanonicalName()
057 {
058 return "ATTR";
059 }
060
061 public TypeValuePair evaluate(FormulaContext context,
062 ParameterCallback parameters)
063 throws EvaluationException
064 {
065 // we expect strings and will check, whether the reference for theses
066 // strings is dirty.
067 if (context instanceof ReportFormulaContext == false)
068 {
069 return new TypeValuePair(ErrorType.TYPE, new LibFormulaErrorValue
070 (LibFormulaErrorValue.ERROR_REFERENCE_NOT_RESOLVABLE));
071 }
072
073 final ReportFormulaContext reportFormulaContext =
074 (ReportFormulaContext) context;
075 Object declaringElement = reportFormulaContext.getDeclaringElement();
076 if (declaringElement instanceof Element == false)
077 {
078 return new TypeValuePair(ErrorType.TYPE, new LibFormulaErrorValue
079 (LibFormulaErrorValue.ERROR_REFERENCE_NOT_RESOLVABLE));
080 }
081
082 final Element element = (Element) declaringElement;
083
084 if (parameters.getParameterCount() == 1)
085 {
086 final String value = (String) parameters.getValue(0);
087 return new TypeValuePair(AnyType.TYPE, element.getAttribute(value));
088 }
089 else if (parameters.getParameterCount() == 2)
090 {
091 final String namespace = (String) parameters.getValue(0);
092 final String attrName = (String) parameters.getValue(1);
093 return new TypeValuePair(AnyType.TYPE,
094 element.getAttribute(namespace, attrName));
095 }
096 return new TypeValuePair(ErrorType.TYPE, new LibFormulaErrorValue
097 (LibFormulaErrorValue.ERROR_INVALID_ARGUMENT));
098 }
099
100 }