/* * The Apache Software License, Version 1.1 * * Copyright (c) 1999 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowlegement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowlegement may appear in the software itself, * if and wherever such third-party acknowlegements normally appear. * * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Group. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.jbpm.jpdl.el.impl; import org.jbpm.jpdl.el.ELException; import org.jbpm.jpdl.el.FunctionMapper; import org.jbpm.jpdl.el.VariableResolver; /** * * <p>Represents a conditional expression. I've decided not to produce an * abstract base "TernaryOperatorExpression" class since (a) future ternary * operators are unlikely and (b) it's not clear that there would be a * meaningful way to abstract them. (For instance, would they all be right- * associative? Would they all have two fixed operator symbols?) * * @author Shawn Bayern **/ public class ConditionalExpression extends Expression { //------------------------------------- // Properties //------------------------------------- // property condition Expression mCondition; public Expression getCondition () { return mCondition; } public void setCondition (Expression pCondition) { mCondition = pCondition; } //------------------------------------- // property trueBranch Expression mTrueBranch; public Expression getTrueBranch () { return mTrueBranch; } public void setTrueBranch (Expression pTrueBranch) { mTrueBranch = pTrueBranch; } //------------------------------------- // property falseBranch Expression mFalseBranch; public Expression getFalseBranch () { return mFalseBranch; } public void setFalseBranch (Expression pFalseBranch) { mFalseBranch = pFalseBranch; } //------------------------------------- /** * * Constructor **/ public ConditionalExpression (Expression pCondition, Expression pTrueBranch, Expression pFalseBranch) { mCondition = pCondition; mTrueBranch = pTrueBranch; mFalseBranch = pFalseBranch; } //------------------------------------- // Expression methods //------------------------------------- /** * * Returns the expression in the expression language syntax **/ public String getExpressionString () { return "( " + mCondition.getExpressionString() + " ? " + mTrueBranch.getExpressionString() + " : " + mFalseBranch.getExpressionString() + " )"; } //------------------------------------- /** * * Evaluates the conditional expression and returns the literal result **/ public Object evaluate (VariableResolver vr, FunctionMapper f, Logger l) throws ELException { // first, evaluate the condition (and coerce the result to a boolean value) boolean condition = Coercions.coerceToBoolean( mCondition.evaluate(vr, f, l), l).booleanValue(); // then, use this boolean to branch appropriately if (condition) return mTrueBranch.evaluate(vr, f, l); else return mFalseBranch.evaluate(vr, f, l); } //------------------------------------- }