001 package org.apache.turbine.services.template; 002 003 004 /* 005 * Licensed to the Apache Software Foundation (ASF) under one 006 * or more contributor license agreements. See the NOTICE file 007 * distributed with this work for additional information 008 * regarding copyright ownership. The ASF licenses this file 009 * to you under the Apache License, Version 2.0 (the 010 * "License"); you may not use this file except in compliance 011 * with the License. You may obtain a copy of the License at 012 * 013 * http://www.apache.org/licenses/LICENSE-2.0 014 * 015 * Unless required by applicable law or agreed to in writing, 016 * software distributed under the License is distributed on an 017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 018 * KIND, either express or implied. See the License for the 019 * specific language governing permissions and limitations 020 * under the License. 021 */ 022 023 024 import java.util.Hashtable; 025 026 /** 027 * This is the interface that all template engine services must adhere 028 * to. This includes the Velocity, WebMacro, FreeMarker, and JSP 029 * services. 030 * 031 * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> 032 * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a> 033 * @version $Id: TemplateEngineService.java 1078552 2011-03-06 19:58:46Z tv $ */ 034 public interface TemplateEngineService 035 { 036 static final String TEMPLATE_EXTENSIONS = "template.extension"; 037 static final String DEFAULT_TEMPLATE_EXTENSION = "template.default.extension"; 038 static final String DEFAULT_PAGE = "default.page"; 039 static final String DEFAULT_SCREEN = "default.screen"; 040 static final String DEFAULT_LAYOUT = "default.layout"; 041 static final String DEFAULT_NAVIGATION = "default.navigation"; 042 static final String DEFAULT_ERROR_SCREEN = "default.error.screen"; 043 static final String DEFAULT_LAYOUT_TEMPLATE = "default.layout.template"; 044 static final String DEFAULT_SCREEN_TEMPLATE = "default.screen.template"; 045 static final String DEFAULT_NAVIGATION_TEMPLATE = "default.navigation.template"; 046 047 /** 048 * Return the configuration of the template engine in 049 * the form of a Hashtable. 050 */ 051 Hashtable<String, Object> getTemplateEngineServiceConfiguration(); 052 053 /** 054 * Initializes file extension associations and registers with the 055 * template service. 056 * 057 * @param defaultExt The default file extension association to use 058 * in case of properties file misconfiguration. 059 */ 060 void registerConfiguration(String defaultExt); 061 062 /** 063 * Supplies the file extension to key this engine in {@link 064 * org.apache.turbine.services.template.TemplateService}'s 065 * registry with. 066 */ 067 String[] getAssociatedFileExtensions(); 068 069 /** 070 * Use the specific template engine to determine whether 071 * a given template exists. This allows Turbine the TemplateService 072 * to delegate the search for a template to the template 073 * engine being used for the view. This gives us the 074 * advantage of fully utilizing the capabilities of 075 * template engine with respect to retrieving templates 076 * from arbitrary sources. 077 * 078 * @param template The name of the template to check the existance of. 079 * @return Whether the specified template exists. 080 */ 081 boolean templateExists(String template); 082 }