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.hivemind;
016
017import java.util.List;
018
019
020/**
021 * Simplified read-only thread safe DOM.
022 * Currently, no support for namespaces, but that may come.
023 *
024 * @author Howard Lewis Ship
025 */
026public interface Element extends Locatable
027{
028        /**
029         * Returns the name of the element, as in, the name of the tag for the element.
030         */
031        public String getElementName();
032        
033        /**
034         * Returns an unmodifiable list of {@link Attribute} for this element.
035         * May return an empty list, but won't return null.  The attributes
036         * are in no specific order.
037         */
038        public List getAttributes();
039        
040        /**
041         * Returns the value for an attribute, or null if the attribute is not specified.
042         */
043        
044        public String getAttributeValue(String attributeName);
045        
046        /**
047         * Returns true if this element contains no other elements.
048         */
049        public boolean isEmpty();
050        
051        /**
052         * Returns an unmodifiable list of {@link Element} directly contained
053         * by this element.  May return an empty list, but won't return null.
054         * The elements are returned in the order in which they were encountered
055         * in the XML.
056         */
057        public List getElements();
058        
059        /**
060         * Returns the content of the element.  This is a concatination of
061         * all the text directly enclosed by the element.  Ignorable whitespace
062         * is ignored.  The content is trimmed of leading and trailing whitespace.
063         */
064        
065        public String getContent();
066}