src/main/java/freemarker/ext/jython/JythonNumberModel.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package freemarker.ext.jython;

import org.python.core.Py;
import org.python.core.PyException;
import org.python.core.PyObject;

import freemarker.ext.util.ModelFactory;
import freemarker.template.ObjectWrapper;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateNumberModel;

/**
 * Model for Jython numeric objects ({@link org.python.core.PyInteger}, {@link org.python.core.PyLong},
 * {@link org.python.core.PyFloat}).
 */
public class JythonNumberModel
extends
    JythonModel
implements
    TemplateNumberModel {
    static final ModelFactory FACTORY =
        new ModelFactory()
        {
            public TemplateModel create(Object object, ObjectWrapper wrapper) {
                return new JythonNumberModel((PyObject) object, (JythonWrapper) wrapper);
            }
        };
        
    public JythonNumberModel(PyObject object, JythonWrapper wrapper) {
        super(object, wrapper);
    }

    /**
     * Returns either {@link PyObject#__tojava__(java.lang.Class)} with
     * {@link java.lang.Number}.class as argument. If that fails, returns 
     * {@link PyObject#__float__()}.
     */
    public Number getAsNumber() throws TemplateModelException {
        try {
            Object value = object.__tojava__(java.lang.Number.class);
            if (value == null || value == Py.NoConversion) {
                return Double.valueOf(object.__float__().getValue());
            }
            return (Number) value;
        } catch (PyException e) {
            throw new TemplateModelException(e);
        }
    }
}