1 package org.apache.turbine.services.template;
2
3
4 /*
5 * Licensed to the Apache Software Foundation (ASF) under one
6 * or more contributor license agreements. See the NOTICE file
7 * distributed with this work for additional information
8 * regarding copyright ownership. The ASF licenses this file
9 * to you under the Apache License, Version 2.0 (the
10 * "License"); you may not use this file except in compliance
11 * with the License. You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing,
16 * software distributed under the License is distributed on an
17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18 * KIND, either express or implied. See the License for the
19 * specific language governing permissions and limitations
20 * under the License.
21 */
22
23
24 import java.util.Hashtable;
25
26 /**
27 * This is the interface that all template engine services must adhere
28 * to. This includes the Velocity, WebMacro, FreeMarker, and JSP
29 * services.
30 *
31 * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
32 * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
33 * @version $Id: TemplateEngineService.java 1078552 2011-03-06 19:58:46Z tv $ */
34 public interface TemplateEngineService
35 {
36 static final String TEMPLATE_EXTENSIONS = "template.extension";
37 static final String DEFAULT_TEMPLATE_EXTENSION = "template.default.extension";
38 static final String DEFAULT_PAGE = "default.page";
39 static final String DEFAULT_SCREEN = "default.screen";
40 static final String DEFAULT_LAYOUT = "default.layout";
41 static final String DEFAULT_NAVIGATION = "default.navigation";
42 static final String DEFAULT_ERROR_SCREEN = "default.error.screen";
43 static final String DEFAULT_LAYOUT_TEMPLATE = "default.layout.template";
44 static final String DEFAULT_SCREEN_TEMPLATE = "default.screen.template";
45 static final String DEFAULT_NAVIGATION_TEMPLATE = "default.navigation.template";
46
47 /**
48 * Return the configuration of the template engine in
49 * the form of a Hashtable.
50 */
51 Hashtable<String, Object> getTemplateEngineServiceConfiguration();
52
53 /**
54 * Initializes file extension associations and registers with the
55 * template service.
56 *
57 * @param defaultExt The default file extension association to use
58 * in case of properties file misconfiguration.
59 */
60 void registerConfiguration(String defaultExt);
61
62 /**
63 * Supplies the file extension to key this engine in {@link
64 * org.apache.turbine.services.template.TemplateService}'s
65 * registry with.
66 */
67 String[] getAssociatedFileExtensions();
68
69 /**
70 * Use the specific template engine to determine whether
71 * a given template exists. This allows Turbine the TemplateService
72 * to delegate the search for a template to the template
73 * engine being used for the view. This gives us the
74 * advantage of fully utilizing the capabilities of
75 * template engine with respect to retrieving templates
76 * from arbitrary sources.
77 *
78 * @param template The name of the template to check the existance of.
79 * @return Whether the specified template exists.
80 */
81 boolean templateExists(String template);
82 }