src/main/java/freemarker/core/IfBlock.java

/*
 * Copyright (c) 2003 The Visigoth Software Society. 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 acknowledgement:
 *       "This product includes software developed by the
 *        Visigoth Software Society (http://www.visigoths.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the 
 *    project contributors may be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact visigoths@visigoths.org.
 *
 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
 *    nor may "FreeMarker" or "Visigoth" appear in their names
 *    without prior written permission of the Visigoth Software Society.
 *
 * 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 VISIGOTH SOFTWARE SOCIETY 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 Visigoth Software Society. For more
 * information on the Visigoth Software Society, please see
 * http://www.visigoths.org/
 */

package freemarker.core;

import java.io.IOException;
import java.util.ArrayList;

import freemarker.template.TemplateException;

/**
 * Container for a group of related #if, #elseif and #else elements.
 * Each such block is a nested {@link ConditionalBlock}. Note that if an #if has no #else of #elseif,
 * {@link ConditionalBlock} doesn't need this parent element. 
 */
final class IfBlock extends TemplateElement {

    IfBlock(ConditionalBlock block)
    {
        nestedElements = new ArrayList();
        addBlock(block);
    }

    void addBlock(ConditionalBlock block) {
        nestedElements.add(block);
    }

    void accept(Environment env) throws TemplateException, IOException {
        for (int i = 0; i<nestedElements.size(); i++) {
            ConditionalBlock cblock = (ConditionalBlock) nestedElements.get(i);
            Expression condition = cblock.condition;
            env.replaceElemetStackTop(cblock);
            if (condition == null || condition.evalToBoolean(env)) {
                if (cblock.nestedBlock != null) {
                    env.visitByHiddingParent(cblock.nestedBlock);
                }
                return;
            }
        }
    }

    TemplateElement postParseCleanup(boolean stripWhitespace)
        throws ParseException 
    {
        if (nestedElements.size() == 1) {
            ConditionalBlock cblock = (ConditionalBlock) nestedElements.get(0);
            cblock.isLonelyIf = true;
            cblock.setLocation(getTemplate(), cblock, this);
            return cblock.postParseCleanup(stripWhitespace);
        }
        else {
            return super.postParseCleanup(stripWhitespace);
        }
    }
    
    protected String dump(boolean canonical) {
        if (canonical) {
            StringBuffer buf = new StringBuffer();
            for (int i = 0; i < nestedElements.size(); i++) {
                ConditionalBlock cblock = (ConditionalBlock) nestedElements.get(i);
                buf.append(cblock.dump(canonical));
            }
            buf.append("</#if>");
            return buf.toString();
        } else {
            return getNodeTypeSymbol();
        }
    }
    
    String getNodeTypeSymbol() {
        return "#if-#elseif-#else-container";
    }
    
    int getParameterCount() {
        return 0;
    }

    Object getParameterValue(int idx) {
        throw new IndexOutOfBoundsException();
    }

    ParameterRole getParameterRole(int idx) {
        throw new IndexOutOfBoundsException();
    }
    
    boolean isShownInStackTrace() {
        return false;
    }
    
}