| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| NamingContainer |
|
| 0.0;0 |
| 1 | /* | |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one | |
| 3 | * or more contributor license agreements. See the NOTICE file | |
| 4 | * distributed with this work for additional information | |
| 5 | * regarding copyright ownership. The ASF licenses this file | |
| 6 | * to you under the Apache License, Version 2.0 (the | |
| 7 | * "License"); you may not use this file except in compliance | |
| 8 | * with the License. You may obtain a copy of the License at | |
| 9 | * | |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 11 | * | |
| 12 | * Unless required by applicable law or agreed to in writing, | |
| 13 | * software distributed under the License is distributed on an | |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
| 15 | * KIND, either express or implied. See the License for the | |
| 16 | * specific language governing permissions and limitations | |
| 17 | * under the License. | |
| 18 | */ | |
| 19 | package javax.faces.component; | |
| 20 | ||
| 21 | /** | |
| 22 | * Interface implemented by components that provide a new "namespace" for the ids of their | |
| 23 | * child components. | |
| 24 | * <p> | |
| 25 | * Component ids must be unique between all descendants of a NamingContainer; the JSF library | |
| 26 | * will report a fatal error and refuse to process or render any view where two components | |
| 27 | * in the same NamingContainer have identical id values. However a component that is a descendant | |
| 28 | * of one NamingContainer component is permitted to have the same id as a component that is a | |
| 29 | * descendant of a different NamingContainer component. | |
| 30 | * <p> | |
| 31 | * Unique component ids are used to: | |
| 32 | * <ul> | |
| 33 | * <li>generate unique names for HTML form fields, etc</li> | |
| 34 | * <li>search for components via UIComponent.findComponent(String expr)</li> | |
| 35 | * <li>on re-render after postback, match up component declarations in the view templates | |
| 36 | * with existing components in the restored view tree. | |
| 37 | * </ul> | |
| 38 | * <p> | |
| 39 | * Requiring every component in a large view (which is possibly built by including or | |
| 40 | * composing multiple files together) to have an id which is different from every other id | |
| 41 | * is simply unmanageable; JSF certainly must provide <i>some</i> kind of id namespacing. | |
| 42 | * Therefore this base class is defined, and a few standard JSF components subclass it | |
| 43 | * (in particular, f:subview). | |
| 44 | * <p> | |
| 45 | * When generating clientId values during rendering, descendants of a NamingContainer instance | |
| 46 | * are allocated a clientId which is their own id prefixed with the clientId of the ancestor | |
| 47 | * NamingContainer, eg "parentId:childId". NamingContainer components can be nested within | |
| 48 | * other NamingContainer components, generating clientIds like "firstId:middleId:leafId". | |
| 49 | * <p> | |
| 50 | * Not every component is a naming container; that would technically work, but the clientId | |
| 51 | * values generated would quickly grow excessively long. | |
| 52 | * <p> | |
| 53 | * See the javadoc for this class in the | |
| 54 | * <a href="http://java.sun.com/j2ee/javaserverfaces/1.2/docs/api/index.html">JSF Specification</a> | |
| 55 | * for further details. | |
| 56 | * | |
| 57 | * @author Manfred Geiler (latest modification by $Author: skitching $) | |
| 58 | * @version $Revision: 685651 $ $Date: 2008-08-13 14:36:16 -0500 (Wed, 13 Aug 2008) $ | |
| 59 | */ | |
| 60 | public interface NamingContainer | |
| 61 | { | |
| 62 | public static final char SEPARATOR_CHAR = ':'; | |
| 63 | } |