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    
015    package org.apache.hivemind.schema;
016    
017    import org.apache.hivemind.Element;
018    import 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     */
028    public 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    }