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 org.apache.hivemind.Locatable;
018    
019    /**
020     * Defines the responsibilities of a template token used by a
021     * {@link org.apache.tapestry.IScript}.
022     * 
023     * @author Howard Lewis Ship
024     */
025    
026    public interface IScriptToken extends Locatable
027    {
028    
029        /**
030         * Invoked to have the token add its text to the buffer. A token may need
031         * access to the symbols in order to produce its output.
032         * <p>
033         * Top level tokens (such as BodyToken) can expect that buffer will be null.
034         */
035    
036        void write(StringBuffer buffer, ScriptSession session);
037    
038        /**
039         * Invoked during parsing to add the token parameter as a child of this
040         * token.
041         * 
042         * @since 0.2.9
043         */
044    
045        void addToken(IScriptToken token);
046    }