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.script;
016    
017    import java.util.Map;
018    
019    import org.apache.hivemind.Resource;
020    import org.apache.tapestry.IRequestCycle;
021    import org.apache.tapestry.IScriptProcessor;
022    
023    /**
024     * Process object used when executing a {@link org.apache.tapestry.IScript script template}. This
025     * ScriptSession provides support
026     * 
027     * @author Howard M. Lewis Ship
028     * @since 4.0
029     */
030    public interface ScriptSession extends IScriptProcessor
031    {
032        /**
033         * Evaluates an OGNL expression, where the root object for the expression is the
034         * {@link #getSymbols() symbols map}.
035         */
036        public Object evaluate(String expression);
037    
038        /**
039         * Returns the resource for the script template.
040         */
041    
042        public Resource getScriptTemplateResource();
043    
044        /**
045         * Returns the symbols (which may be created or updated during the execution of the script
046         * template).
047         */
048    
049        public Map getSymbols();
050    
051        /**
052         * Returns the current request cycle.
053         */
054        public IRequestCycle getRequestCycle();
055    
056        /**
057         * Evaluates an expression and coerces the result to a particlar type.
058         * 
059         * @since 4.0
060         * @see org.apache.tapestry.coerce.ValueConverter
061         */
062    
063        public Object evaluate(String expression, Class desiredType);
064    }