001    // Copyright 2008 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.Block;
018    import org.apache.tapestry5.ioc.annotations.UsesConfiguration;
019    
020    /**
021     * Used to override the default {@link org.apache.tapestry5.services.BeanBlockSource} for a particular data type.  The
022     * service accepts the same configuration of {@link org.apache.tapestry5.services.BeanBlockContribution}s as the main
023     * service.
024     */
025    @UsesConfiguration(BeanBlockContribution.class)
026    public interface BeanBlockOverrideSource
027    {
028        /**
029         * Returns a block which can be used to render an editor for the given data type, in the form of a field label and
030         * input field.
031         *
032         * @param datatype logical name for the type of data to be displayed
033         * @return the Block
034         * @throws null if no override is available
035         */
036        Block getEditBlock(String datatype);
037    
038        /**
039         * Returns a block which can be used to render output for the given data type.
040         *
041         * @param datatype logical name for the type of data to be displayed
042         * @return the Block
043         * @throws null if no override is available
044         */
045        Block getDisplayBlock(String datatype);
046    
047        /**
048         * Checks to see if there is a display block for the indicated data type.
049         *
050         * @param datatype to check for
051         * @return true if an override display block is available
052         */
053        boolean hasDisplayBlock(String datatype);
054    }