| // Copyright 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; |
| |
| /** |
| * Defines a strategy, used by {@link Field} components such as {@link org.apache.tapestry5.corelib.components.TextField}, |
| * to handle the case where either the server-side value to be sent (as a string) to the client, or the client-side |
| * string passed back up to the server, is null or blank. |
| * |
| * @see org.apache.tapestry5.services.NullFieldStrategySource |
| */ |
| public interface NullFieldStrategy |
| { |
| /** |
| * Provides a replacement value for null, when converting the server-side object to a client-side string. The |
| * replacement value, if non-null, will be passed to {@link org.apache.tapestry5.Translator#toClient(Object)}. |
| */ |
| Object replaceToClient(); |
| |
| /** |
| * Provides a replacement value for a null or blank string passed from the client to the server as part of a form |
| * submission. This replacement value will be passed to {@link org.apache.tapestry5.Translator#parseClient(String, |
| * org.apache.tapestry5.ioc.Messages)} as if it were the value supplied by the user. |
| * |
| * @return replacement value (this must not be null) |
| */ |
| String replaceFromClient(); |
| } |