001// Copyright 2004, 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry.util;
016
017import java.util.List;
018
019/**
020 *  An interface that defines an object that can store named propertys.  The names
021 *  and the properties are Strings.
022 *
023 *  @author Howard Lewis Ship
024 *
025 **/
026
027public interface IPropertyHolder
028{
029    /**
030     *  Returns a List of Strings, the names of all
031     *  properties held by the receiver.  May return an empty list.
032     *  The List is sorted alphabetically.  The List may be modified
033     *  without affecting this property holder.
034     *
035     *  <p>Prior to release 2.2, this method returned Collection.
036     * 
037     **/
038
039    public List getPropertyNames();
040
041    /**
042     *  Sets a named property.  The new value replaces the existing value, if any.
043     *  Setting a property to null is the same as removing the property.
044     *
045     **/
046
047    public void setProperty(String name, String value);
048
049    /**
050     *  Removes the named property, if present.
051     *
052     **/
053
054    public void removeProperty(String name);
055
056    /**
057     *  Retrieves the named property, or null if the property is not defined.
058     *
059     **/
060
061    public String getProperty(String name);
062}