| // Copyright 2004 The Apache Software Foundation |
| // |
| // Licensed 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 org.apache.tapestry.bean; |
| |
| import org.apache.tapestry.IBinding; |
| import org.apache.tapestry.util.pool.IPoolable; |
| |
| /** |
| * A helper bean to assist with providing defaults for unspecified |
| * parameters. It is initalized |
| * with an {@link IBinding} and a default value. It's value property |
| * is either the value of the binding, but if the binding is null, |
| * or the binding returns null, the default value is returned. |
| * |
| * @author Howard Lewis Ship |
| * @version $Id$ |
| * @since 1.0.5 |
| * |
| **/ |
| |
| public class Default implements IPoolable |
| { |
| private IBinding binding; |
| private Object defaultValue; |
| |
| public void resetForPool() |
| { |
| binding = null; |
| defaultValue = null; |
| } |
| |
| public void setBinding(IBinding value) |
| { |
| binding = value; |
| } |
| |
| public IBinding getBinding() |
| { |
| return binding; |
| } |
| |
| public void setDefaultValue(Object value) |
| { |
| defaultValue = value; |
| } |
| |
| public Object getDefaultValue() |
| { |
| return defaultValue; |
| } |
| |
| /** |
| * Returns the value of the binding. However, if the binding is null, or the binding |
| * returns null, then the defaultValue is returned instead. |
| * |
| **/ |
| |
| public Object getValue() |
| { |
| if (binding == null) |
| return defaultValue; |
| |
| Object value = binding.getObject(); |
| |
| if (value == null) |
| return defaultValue; |
| |
| return value; |
| } |
| |
| /** @since 3.0 **/ |
| |
| public void discardFromPool() |
| { |
| } |
| |
| } |