    001    // Copyright 2007, 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     * 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.services.TapestryModule#provideDefaultBeanBlocks(org.apache.tapestry5.ioc.Configuration)
    034     */
    035    @UsesConfiguration(BeanBlockContribution.class)
    036    public 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    }