freemarker.core.EvaluationUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of freemarker-gae
Google App Engine compliant variation of FreeMarker. FreeMarker is a "template engine"; a generic tool to generate text output based on templates.
There is a newer version: 2.3.33
Show newest version
/*
 * 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 [email protected].
 *
 * 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.util.Date;
import freemarker.template.*;

/**
 * @version 1.0
 * @author Attila Szegedi
 */
class EvaluationUtil
{
    private EvaluationUtil()
    {
    }
    
    static String getString(TemplateScalarModel model, Expression expr, Environment env)
    throws
        TemplateException
    {
        String value = model.getAsString();
        if(value == null)
        {
            if(env.isClassicCompatible())
            {
                return "";
            }
            else
            {
                throw new TemplateException(expr + " evaluated to null string.", env);
            }
        }
        return value;
    }

    static Number getNumber(Expression expr, Environment env)
    throws
        TemplateException
    {
        TemplateModel model = expr.getAsTemplateModel(env);
        return getNumber(model, expr, env);
    }

    static Number getNumber(TemplateModel model, Expression expr, Environment env)
    throws
        TemplateException
    {
        if(model instanceof TemplateNumberModel)
        {
            return getNumber((TemplateNumberModel)model, expr, env);
        }
        else if(model == null) {
            throw new InvalidReferenceException(expr + " is undefined.", env);
        }
        else
        {
            throw new NonNumericalException(expr + " is not a number, it is " + model.getClass().getName(), env);
        }
    }

    static Number getNumber(TemplateNumberModel model, Expression expr, Environment env)
        throws TemplateModelException, TemplateException
    {
        Number value = model.getAsNumber();
        if(value == null) {
            throw new TemplateException(expr + " evaluated to null number.", env);
        }
        return value;
    }

    static Date getDate(TemplateDateModel model, Expression expr, Environment env)
        throws TemplateModelException, TemplateException
    {
        Date value = model.getAsDate();
        if(value == null) {
            throw new TemplateException(expr + " evaluated to null date.", env);
        }
        return value;
    }
}