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.tapestry.services;
016    
017    import org.apache.tapestry.corelib.components.BeanEditForm;
018    import org.apache.tapestry.corelib.components.Grid;
019    import org.apache.tapestry.ioc.services.PropertyAdapter;
020    
021    /**
022     * Used by {@link BeanModelSource} to identify the type of data associated with a particular property (represented as a
023     * {@link PropertyAdapter}). The data type is a string used to determine what kind of interface to use for displaying
024     * the value of the property, or what kind of interface to use for editing the value of the property. Common property
025     * types are "text", "enum", "checkbox", but the list is extensible.
026     * <p/>
027     * <p>Different strategies for identifying the data type are encapsulated in the DataTypeAnalyzer service, forming a
028     * chain of command.
029     *
030     * @see Grid
031     * @see BeanEditForm
032     * @see BeanBlockSource
033     * @see org.apache.tapestry.services.TapestryModule#contributeDataTypeAnalyzer(org.apache.tapestry.ioc.OrderedConfiguration,
034     *      DataTypeAnalyzer)
035     */
036    public interface DataTypeAnalyzer
037    {
038        /**
039         * Identifies the data type, if known, or returns null if not known.
040         */
041        String identifyDataType(PropertyAdapter adapter);
042    }