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1   /*
2    * Copyright 2006-2016 The JGUIraffe Team.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License")
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package net.sf.jguiraffe.transform;
17  
18  /**
19   * <p>
20   * Definition of an interface for a central instance that manages validation
21   * messages.
22   * </p>
23   * <p>
24   * This interface is used by concrete <code>{@link Validator}</code>
25   * implementations to obtain meaningful error messages when they decide that
26   * user input is not valid. An object implementing this interface can be queried
27   * from the <code>{@link TransformerContext}</code>. It can then be used for
28   * requesting <code>{@link ValidationMessage}</code> objects for specified
29   * keys.
30   * </p>
31   * <p>
32   * Because all validation error messages are obtained through this interface, it
33   * provides a way for hooking into the mechanism of creating error messages.
34   * While the framework ships a fully functional default implementation, an
35   * application with completely different requirements can choose to use a custom
36   * implementation.
37   * </p>
38   *
39   * @author Oliver Heger
40   * @version $Id: ValidationMessageHandler.java 205 2012-01-29 18:29:57Z oheger $
41   */
42  public interface ValidationMessageHandler
43  {
44      /**
45       * Returns a <code>ValidationMessage</code> object for the specified key.
46       * The message will be initialized with the given parameters. From this
47       * object the final error message can be obtained.
48       *
49       * @param context the transformer context
50       * @param key the key for the validation message
51       * @param params an array with additional parameters
52       * @return the corresponding <code>ValidationMessage</code> object
53       */
54      ValidationMessage getValidationMessage(TransformerContext context,
55              String key, Object... params);
56  }