001 // Copyright 2005 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.tapestry.services; 016 017 import java.util.Locale; 018 019 import org.apache.tapestry.IComponent; 020 import org.apache.tapestry.INamespace; 021 022 /** 023 * Enapsulates the logic for searching for component meta-data. Deployed as service 024 * tapestry.props.ComponentPropertySource. 025 * <p> 026 * TODO: Adjust name, since it now provides access to namespace properties as well as component 027 * properties. 028 * 029 * @author Howard M. Lewis Ship 030 * @since 4.0 031 */ 032 public interface ComponentPropertySource 033 { 034 /** 035 * Returns the property value for a particular named meta-data property of the component. The 036 * search order is: 037 * <ul> 038 * <li>The component's specification</li> 039 * <li>The specification of the application (or the library containing the component).</li> 040 * <li>The chain of global property sources.</li> 041 * </ul> 042 * 043 * @return the value of the given key, or null if not found. 044 */ 045 046 public String getComponentProperty(IComponent component, String propertyName); 047 048 /** 049 * Like {@link #getComponentProperty(IComponent, String)}, but the property name will be 050 * localized to the component's current locale (determined from its page). Localizing the 051 * property name means that a suffix may be appended to it. If the fully localized name is not 052 * found, then the locale is generalized (i.e., from "en_UK" to "en" to nothing) until a match 053 * is found. 054 * 055 * @return the value of the given property name, or null if not found. 056 */ 057 public String getLocalizedComponentProperty(IComponent component, Locale locale, 058 String propertyName); 059 060 /** 061 * Returns the property value for a particular named meta-data property of the namespace. The 062 * search order is: 063 * <ul> 064 * <li>The library or application specification for the namespace.</li> 065 * <li>The chain of global property sources.</li> 066 * </ul> 067 * 068 * @return the value of the given key, or null if not found. 069 */ 070 071 public String getNamespaceProperty(INamespace namespace, String propertyName); 072 073 /** 074 * As with {@link #getLocalizedComponentProperty(IComponent, Locale, String)}, but with a 075 * {@link INamespace}. 076 */ 077 078 public String getLocalizedNamespaceProperty(INamespace namespace, Locale locale, 079 String propertyName); 080 }