// Copyright 2007, 2008 The Apache Software Foundation

 //

 // Licensed under the Apache License, Version 2.0 (the "License");

 // you may not use this file except in compliance with the License.

 // You may obtain a copy of the License at

 //

 //     http://www.apache.org/licenses/LICENSE-2.0

 //

 // Unless required by applicable law or agreed to in writing, software

 // distributed under the License is distributed on an "AS IS" BASIS,

 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 // See the License for the specific language governing permissions and

 // limitations under the License.

 package org.apache.tapestry5.services;

 import org.apache.tapestry5.Block;

 import org.apache.tapestry5.ioc.annotations.UsesConfiguration;

 /**

  * A source of {@link Block}s used to display the properties of a bean (used by the {@link

  * org.apache.tapestry5.corelib.components.Grid} component), or to edit the properties of a bean (used by the {@link

  * org.apache.tapestry5.corelib.components.BeanEditForm} component). Contributions to this service (a configuration of

  * {@link BeanBlockContribution}s) define what properties may be editted.

  * <p/>

  * Blocks are accessed in terms of a <strong>data type</strong> a string that identifies the type of data to be editted,

  * such as "string", "date", "boolean", etc.

  * <p/>

  * Tapestry contributes a number of default data types and corresponding edit and display blocks. The {@link

  * org.apache.tapestry5.services.BeanBlockOverrideSource} service allows these to be overridden.

  *

  * @see org.apache.tapestry5.services.DataTypeAnalyzer

  * @see org.apache.tapestry5.services.TapestryModule#contributeBeanBlockSource(org.apache.tapestry5.ioc.Configuration)

  */

 @UsesConfiguration(BeanBlockContribution.class)

 public interface BeanBlockSource

 {

     /**

      * Returns a block which can be used to render an editor for the given data type, in the form of a field label and

      * input field.

      *

      * @param datatype logical name for the type of data to be displayed

      * @return the Block

      * @throws RuntimeException if no appropriate block is available

      */

     Block getEditBlock(String datatype);

     /**

      * Returns a block which can be used to render output for the given data type.

      *

      * @param datatype logical name for the type of data to be displayed

      * @return the Block

      * @throws RuntimeException if no appropriate block is available

      */

     Block getDisplayBlock(String datatype);

     /**

      * Checks to see if there is a display block for the indicated data type.

      *

      * @param datatype to check for

      * @return true if a block is available

      */

     boolean hasDisplayBlock(String datatype);

 }