001    // Copyright 2007 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.tapestry5.services;
016    
017    import org.apache.tapestry5.corelib.components.Grid;
018    import org.apache.tapestry5.ioc.Messages;
019    
020    /**
021     * Provides context information needed when displaying a value. This interface is an integral part of the {@link Grid}
022     * and similar output components.    It is made available to components via an {@link
023     * org.apache.tapestry5.annotations.Environmental} annotation.
024     */
025    public interface PropertyOutputContext
026    {
027        /**
028         * Returns the value of the property (the object being displayed is encapsulated by the context).
029         */
030        Object getPropertyValue();
031    
032        /**
033         * Returns the message catalog appropriate for use. In practice, this is the message catalog of the container of the
034         * {@link Grid} component. This is used, for example, to locate labels for fields, or to locate string
035         * representations of Enums.
036         */
037        Messages getMessages();
038    
039        /**
040         * Returns a string that identifies the property, usually the property name. This is used as the basis for the
041         * client-side client id.
042         */
043        String getPropertyId();
044    
045        /**
046         * Returns the name of the property (which may, in fact, be a property expression).
047         */
048        String getPropertyName();
049    }