src/main/java/freemarker/core/AssignmentInstruction.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;

/**
 * An instruction that does multiple assignments, like [#local x=1 x=2].
 * Each assignment is represented by a {@link Assignment} child element.
 * If there's only one assignment, its usually just a {@link Assignment} without parent {@link AssignmentInstruction}.
 */
final class AssignmentInstruction extends TemplateElement {

    private int scope;
    private Expression namespaceExp;

    AssignmentInstruction(int scope) {
        this.scope = scope;
        nestedElements = new ArrayList(1);
    }

    void addAssignment(Assignment ass) {
        nestedElements.add(ass);
    }
    
    void setNamespaceExp(Expression namespaceExp) {
        this.namespaceExp = namespaceExp;
        for (int i=0; i<nestedElements.size();i++) {
            ((Assignment) nestedElements.get(i)).setNamespaceExp(namespaceExp);
        }
    }

    void accept(Environment env) throws TemplateException, IOException {
        for (int i = 0; i<nestedElements.size(); i++) {
            Assignment ass = (Assignment) nestedElements.get(i);
            env.visit(ass);
        }
    }

    protected String dump(boolean canonical) {
        StringBuffer buf = new StringBuffer();
        if (canonical) buf.append('<');
        buf.append(Assignment.getDirectiveName(scope));
        if (canonical) {
            buf.append(' ');
            for (int i = 0; i<nestedElements.size(); i++) {
                Assignment ass = (Assignment) nestedElements.get(i);
                buf.append(ass.getCanonicalForm());
                if (i < nestedElements.size() -1) {
                    buf.append(" ");
                }
            }
        } else {
            buf.append("-container");
        }
        if (namespaceExp != null) {
            buf.append(" in ");
            buf.append(namespaceExp.getCanonicalForm());
        }
        if (canonical) buf.append("/>");
        return buf.toString();
    }
    
    int getParameterCount() {
        return 2;
    }

    Object getParameterValue(int idx) {
        switch (idx) {
        case 0: return new Integer(scope);
        case 1: return namespaceExp;
        default: return null;
        }
    }

    ParameterRole getParameterRole(int idx) {
        switch (idx) {
        case 0: return ParameterRole.VARIABLE_SCOPE;
        case 1: return ParameterRole.NAMESPACE;
        default: return null;
        }
    }
    
    String getNodeTypeSymbol() {
        return Assignment.getDirectiveName(scope);
    }

    public TemplateElement postParseCleanup(boolean stripWhitespace) throws ParseException {
        super.postParseCleanup(stripWhitespace);
        if (nestedElements.size() == 1) {
            Assignment ass = (Assignment) nestedElements.get(0);
            ass.setLocation(getTemplate(), this, this);
            return ass;
        } 
        return this;
    }
}