    001// Copyright 2007, 2008, 2011 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
    015package org.apache.tapestry5.services;
    016
    017import org.apache.tapestry5.ioc.annotations.UsesMappedConfiguration;
    018import org.apache.tapestry5.ioc.annotations.UsesOrderedConfiguration;
    019import org.apache.tapestry5.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 * Different strategies for identifying the data type are encapsulated in the DataTypeAnalyzer service, forming a
    028 * chain of command.
    029 * <p/>
    030 * The DefaultDataTypeAnalyzer service maps property types to data type names.
    031 * <p/>
    032 * The DataTypeAnalyzer service is an extensible {@linkplain org.apache.tapestry5.ioc.services.ChainBuilder chain of
    033 * command}), that (by default) includes {@link org.apache.tapestry5.internal.services.AnnotationDataTypeAnalyzer} and
    034 * the {@link org.apache.tapestry5.internal.services.DefaultDataTypeAnalyzer} service (ordered last).   It uses an ordered configuration.
    035 *
    036 * @see org.apache.tapestry5.corelib.components.Grid
    037 * @see org.apache.tapestry5.corelib.components.BeanEditForm
    038 * @see BeanBlockSource
    039 */
    040@UsesOrderedConfiguration(DataTypeAnalyzer.class)
    041@UsesMappedConfiguration(key = Class.class, value = String.class)
    042public interface DataTypeAnalyzer
    043{
    044    /**
    045     * Identifies the data type, if known, or returns null if not known.
    046     */
    047    String identifyDataType(PropertyAdapter adapter);
    048}