001// Copyright 2007-2013 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.Block;
018import org.apache.tapestry5.ioc.annotations.UsesConfiguration;
019
020/**
021 * A source of {@link Block}s used to display the properties of a bean (used by the {@link
022 * org.apache.tapestry5.corelib.components.Grid} component), or to edit the properties of a bean (used by the {@link
023 * org.apache.tapestry5.corelib.components.BeanEditForm} component). Contributions to this service (a configuration of
024 * {@link BeanBlockContribution}s) define what properties may be editted.
025 * <p/>
026 * Blocks are accessed in terms of a <strong>data type</strong> a string that identifies the type of data to be editted,
027 * such as "string", "date", "boolean", etc.
028 * <p/>
029 * Tapestry contributes a number of default data types and corresponding edit and display blocks. The {@link
030 * org.apache.tapestry5.services.BeanBlockOverrideSource} service allows these to be overridden.
031 *
032 * @see org.apache.tapestry5.services.DataTypeAnalyzer
033 * @see org.apache.tapestry5.modules.TapestryModule#provideDefaultBeanBlocks(org.apache.tapestry5.ioc.Configuration)
034 */
035@UsesConfiguration(BeanBlockContribution.class)
036public interface BeanBlockSource
037{
038    /**
039     * Returns a block which can be used to render an editor for the given data type, in the form of a field label and
040     * input field.
041     *
042     * @param datatype logical name for the type of data to be displayed
043     * @return the Block
044     * @throws RuntimeException if no appropriate block is available
045     */
046    Block getEditBlock(String datatype);
047
048    /**
049     * Returns a block which can be used to render output for the given data type.
050     *
051     * @param datatype logical name for the type of data to be displayed
052     * @return the Block
053     * @throws RuntimeException if no appropriate block is available
054     */
055    Block getDisplayBlock(String datatype);
056
057    /**
058     * Checks to see if there is a display block for the indicated data type.
059     *
060     * @param datatype to check for
061     * @return true if a block is available
062     */
063    boolean hasDisplayBlock(String datatype);
064}