| /* |
| * 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.template.utility; |
| |
| import java.io.Serializable; |
| |
| import freemarker.template.SimpleNumber; |
| import freemarker.template.TemplateBooleanModel; |
| import freemarker.template.TemplateCollectionModel; |
| import freemarker.template.TemplateHashModelEx; |
| import freemarker.template.TemplateModel; |
| import freemarker.template.TemplateModelException; |
| import freemarker.template.TemplateModelIterator; |
| import freemarker.template.TemplateNumberModel; |
| import freemarker.template.TemplateScalarModel; |
| import freemarker.template.TemplateSequenceModel; |
| |
| /** |
| * Frequently used constant {@link TemplateModel} values. |
| * |
| * <p>These constants should be stored in the {@link TemplateModel} |
| * sub-interfaces, but for bacward compatibility they are stored here instead. |
| * Starting from FreeMarker 2.4 they should be copyed (not moved!) into the |
| * {@link TemplateModel} sub-interfaces, and this class should be marked as |
| * deprecated.</p> |
| */ |
| public class Constants { |
| |
| public static final TemplateBooleanModel TRUE = TemplateBooleanModel.TRUE; |
| |
| public static final TemplateBooleanModel FALSE = TemplateBooleanModel.FALSE; |
| |
| public static final TemplateScalarModel EMPTY_STRING = (TemplateScalarModel) TemplateScalarModel.EMPTY_STRING; |
| |
| public static final TemplateNumberModel ZERO = new SimpleNumber(0); |
| |
| public static final TemplateNumberModel ONE = new SimpleNumber(1); |
| |
| public static final TemplateNumberModel MINUS_ONE = new SimpleNumber(-1); |
| |
| public static final TemplateModelIterator EMPTY_ITERATOR = new EmptyIteratorModel(); |
| |
| private static class EmptyIteratorModel implements TemplateModelIterator, Serializable { |
| |
| public TemplateModel next() throws TemplateModelException { |
| throw new TemplateModelException("The collection has no more elements."); |
| } |
| |
| public boolean hasNext() throws TemplateModelException { |
| return false; |
| } |
| |
| } |
| |
| public static final TemplateCollectionModel EMPTY_COLLECTION = new EmptyCollectionModel(); |
| |
| private static class EmptyCollectionModel implements TemplateCollectionModel, Serializable { |
| |
| public TemplateModelIterator iterator() throws TemplateModelException { |
| return EMPTY_ITERATOR; |
| } |
| |
| } |
| |
| public static final TemplateSequenceModel EMPTY_SEQUENCE = new EmptySequenceModel(); |
| |
| private static class EmptySequenceModel implements TemplateSequenceModel, Serializable { |
| |
| public TemplateModel get(int index) throws TemplateModelException { |
| return null; |
| } |
| |
| public int size() throws TemplateModelException { |
| return 0; |
| } |
| |
| } |
| |
| public static final TemplateHashModelEx EMPTY_HASH = new EmptyHashModel(); |
| |
| private static class EmptyHashModel implements TemplateHashModelEx, Serializable { |
| |
| public int size() throws TemplateModelException { |
| return 0; |
| } |
| |
| public TemplateCollectionModel keys() throws TemplateModelException { |
| return EMPTY_COLLECTION; |
| } |
| |
| public TemplateCollectionModel values() throws TemplateModelException { |
| return EMPTY_COLLECTION; |
| } |
| |
| public TemplateModel get(String key) throws TemplateModelException { |
| return null; |
| } |
| |
| public boolean isEmpty() throws TemplateModelException { |
| return true; |
| } |
| |
| } |
| |
| } |