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.tapestry.services;
016    
017    /**
018     * Cache of compiled OGNL expressions.
019     * 
020     * @author Howard M. Lewis Ship
021     * @since 4.0
022     */
023    public interface ExpressionCache
024    {
025        /**
026         * Returns the compiled form of the OGNL expression. 
027         * 
028         * @throws org.apache.hivemind.ApplicationRuntimeException if the expression is not valid
029         */
030        public Object getCompiledExpression(String expression);
031    }