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: AbstractExpressionReadHandler.java 3525 2007-10-16 11:43:48Z tmorgner $ 027 * ------------ 028 * (C) Copyright 2000-2005, by Object Refinery Limited. 029 * (C) Copyright 2005-2007, by Pentaho Corporation. 030 */ 031 package org.jfree.report.modules.factories.report.flow; 032 033 import java.beans.IntrospectionException; 034 035 import org.jfree.report.expressions.Expression; 036 import org.jfree.report.expressions.FormulaExpression; 037 import org.jfree.report.expressions.FormulaFunction; 038 import org.jfree.report.util.CharacterEntityParser; 039 import org.jfree.report.util.beans.BeanUtility; 040 import org.jfree.util.ObjectUtilities; 041 import org.jfree.xmlns.parser.AbstractXmlReadHandler; 042 import org.jfree.xmlns.parser.ParseException; 043 import org.jfree.xmlns.parser.XmlReadHandler; 044 import org.xml.sax.Attributes; 045 import org.xml.sax.SAXException; 046 047 /** 048 * Creation-Date: 09.04.2006, 13:23:32 049 * 050 * @author Thomas Morgner 051 */ 052 public abstract class AbstractExpressionReadHandler 053 extends AbstractXmlReadHandler 054 { 055 private Expression expression; 056 private BeanUtility expressionBeanUtility; 057 private CharacterEntityParser characterEntityParser; 058 059 public AbstractExpressionReadHandler() 060 { 061 this.characterEntityParser = CharacterEntityParser.createXMLEntityParser(); 062 } 063 064 protected String getDefaultClassName() 065 { 066 return null; 067 } 068 069 /** 070 * Starts parsing. 071 * 072 * @param attrs the attributes. 073 * @throws SAXException if there is a parsing error. 074 */ 075 protected void startParsing(final Attributes attrs) throws SAXException 076 { 077 final String name = attrs.getValue(getUri(), "name"); 078 String className = attrs.getValue(getUri(), "class"); 079 final String formula = attrs.getValue(getUri(), "formula"); 080 if (className == null) 081 { 082 if (formula != null) 083 { 084 final String initial = attrs.getValue(getUri(), "initial"); 085 if (initial != null) 086 { 087 final FormulaFunction function = new FormulaFunction(); 088 function.setInitial(initial); 089 function.setFormula(formula); 090 this.expression = function; 091 } 092 else 093 { 094 final FormulaExpression expression = new FormulaExpression(); 095 expression.setFormula(formula); 096 this.expression = expression; 097 } 098 } 099 else 100 { 101 className = getDefaultClassName(); 102 if (className == null) 103 { 104 throw new ParseException("Required attribute 'class' is missing.", 105 getRootHandler().getDocumentLocator()); 106 } 107 } 108 } 109 110 if (expression == null) 111 { 112 expression = (Expression) ObjectUtilities.loadAndInstantiate 113 (className, AbstractExpressionReadHandler.class, Expression.class); 114 if (expression == null) 115 { 116 throw new ParseException("Expression '" + className + 117 "' is not valid. The specified class is not an expression or function.", 118 getRootHandler().getDocumentLocator()); 119 } 120 } 121 122 expression.setName(name); 123 expression.setDeepTraversing("true".equals(attrs.getValue(getUri(), "deep-traversing"))); 124 expression.setPrecompute("true".equals(attrs.getValue(getUri(), "precompute"))); 125 expression.setPreserve("true".equals(attrs.getValue(getUri(), "preserve"))); 126 127 try 128 { 129 expressionBeanUtility = new BeanUtility(expression); 130 } 131 catch (ClassCastException e) 132 { 133 throw new ParseException("Expression '" + className + 134 "' is not valid. The specified class is not an expression or function.", 135 e, getRootHandler().getDocumentLocator()); 136 } 137 catch (IntrospectionException e) 138 { 139 throw new ParseException("Expression '" + className + 140 "' is not valid. Introspection failed for this expression.", 141 e, getRootHandler().getDocumentLocator()); 142 } 143 144 } 145 146 /** 147 * Returns the handler for a child element. 148 * 149 * @param tagName the tag name. 150 * @param atts the attributes. 151 * @return the handler or null, if the tagname is invalid. 152 * @throws SAXException if there is a parsing error. 153 */ 154 protected XmlReadHandler getHandlerForChild(final String uri, 155 final String tagName, 156 final Attributes atts) 157 throws SAXException 158 { 159 if (isSameNamespace(uri) == false) 160 { 161 return null; 162 } 163 if ("property".equals(tagName)) 164 { 165 return new TypedPropertyReadHandler 166 (expressionBeanUtility, expression.getName(), 167 characterEntityParser); 168 } 169 return null; 170 } 171 172 public Expression getExpression() 173 { 174 return expression; 175 } 176 177 /** 178 * Returns the object for this element or null, if this element does not 179 * create an object. 180 * 181 * @return the object. 182 * @throws SAXException if there is a parsing error. 183 */ 184 public Object getObject() throws SAXException 185 { 186 return expression; 187 } 188 }