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.schema;
016
017import org.apache.hivemind.Element;
018import org.apache.hivemind.Locatable;
019
020/**
021 * Rules associated with {@link org.apache.hivemind.schema.Schema} elements.
022 * As the {@link org.apache.hivemind.schema.SchemaProcessor}
023 * works through the {@link org.apache.hivemind.Element} hiearchy, it invokes
024 * methods on the Rules.
025 * 
026 * @author Howard M. Lewis Ship
027 */
028public interface Rule extends Locatable
029{
030        /**
031         * Begin rules are fired first, in order.  All rules are invoked, and then the
032         * SchemaProcessor recurses into the elements contained within the element.
033         */
034    public void begin(SchemaProcessor processor, Element element);
035
036        /**
037         * End rules are fired last, in inverse order.
038         */
039    public void end(SchemaProcessor processor, Element element);
040}