Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
DelegatingTemplateProvider |
|
| 4.2;4.2 |
1 | /* | |
2 | * Copyright (C) 1998-2000 Semiotek Inc. All Rights Reserved. | |
3 | * | |
4 | * Redistribution and use in source and binary forms, with or without | |
5 | * modification, are permitted under the terms of either of the following | |
6 | * Open Source licenses: | |
7 | * | |
8 | * The GNU General Public License, version 2, or any later version, as | |
9 | * published by the Free Software Foundation | |
10 | * (http://www.fsf.org/copyleft/gpl.html); | |
11 | * | |
12 | * or | |
13 | * | |
14 | * The Semiotek Public License (http://webmacro.org/LICENSE.) | |
15 | * | |
16 | * This software is provided "as is", with NO WARRANTY, not even the | |
17 | * implied warranties of fitness to purpose, or merchantability. You | |
18 | * assume all risks and liabilities associated with its use. | |
19 | * | |
20 | * See www.webmacro.org for more information on the WebMacro project. | |
21 | */ | |
22 | ||
23 | ||
24 | package org.webmacro.resource; | |
25 | ||
26 | import java.util.ArrayList; | |
27 | import java.util.Arrays; | |
28 | import java.util.Collections; | |
29 | import java.util.List; | |
30 | ||
31 | import org.slf4j.Logger; | |
32 | import org.slf4j.LoggerFactory; | |
33 | import org.webmacro.Broker; | |
34 | import org.webmacro.Context; | |
35 | import org.webmacro.InitException; | |
36 | import org.webmacro.NotFoundException; | |
37 | import org.webmacro.ResourceException; | |
38 | import org.webmacro.Template; | |
39 | import org.webmacro.util.Settings; | |
40 | ||
41 | /** | |
42 | * Alternative implementation of a TemplateProvider that uses TemplateLoaders to do the actual work. | |
43 | * This template provider controls a list of TemplateLoaders to do the actual work of loading | |
44 | * a template. It asks the template loaders one by one, until a template is found or the end of | |
45 | * the list is reached. It is configured by a list of "TemplateLoaderPath.n" settings in | |
46 | * WebMacro.properties.<br> | |
47 | * <br> | |
48 | * Each template loader is described by an url like syntax with a TemplateLoaderPath.n setting, | |
49 | * where n should be a number starting from one. | |
50 | * <br> | |
51 | * Each template loader path is of the form "[protocol:][path]". If the protocol part in square brackets | |
52 | * is ommited, "default:" is assumed. | |
53 | * For each protocol, a "TemplateLoader.protocol" setting must give the fully qualified | |
54 | * classname of the template loader to be used for this protocol. | |
55 | * Example configuration:<br> | |
56 | * <pre> | |
57 | * TemplateLoaderPath.1=. | |
58 | * TemplateLoaderPath.2=classpath: | |
59 | * TemplateLoaderPath.3=webapp:/WEB-INF/templates/ | |
60 | * TemplateLoader.default=org.webmacro.resource.FileTemplateLoader | |
61 | * TemplateLoader.classpath=org.webmacro.resource.ClassPathTemplateLoader | |
62 | * TemplateLoader.webapp=org.webmacro.resource.ServletContextTemplateLoader | |
63 | * </pre> | |
64 | * This configuration will search for templates at three locations in this order: | |
65 | * <ol> | |
66 | * <li>The current directory (".") | |
67 | * <li>The classpath (classpath:) | |
68 | * <li>The directory WEB-INF/templates/ in the web-app directory ("webapp:/WEB-INF/templates/") | |
69 | * </ol> | |
70 | * NOTE This setup only makes sense in a web-app environment, because the webapp template loader | |
71 | * won't work otherwise. | |
72 | * @author Sebastian Kanthak (sebastian.kanthak@muehlheim.de) | |
73 | */ | |
74 | 0 | public class DelegatingTemplateProvider extends CachingProvider |
75 | { | |
76 | ||
77 | 0 | static Logger _log = LoggerFactory.getLogger(DelegatingTemplateProvider.class); |
78 | ||
79 | private TemplateLoaderFactory factory; | |
80 | private TemplateLoader[] templateLoaders; | |
81 | ||
82 | public void init (Broker broker, Settings config) throws InitException | |
83 | { | |
84 | 0 | super.init(broker, config); |
85 | ||
86 | 0 | String factoryClass = config.getSetting("TemplateLoaderFactory", ""); |
87 | 0 | _log.info("DelegatingTemplateProvider: Using TemplateLoaderFactory " + factoryClass); |
88 | 0 | factory = createFactory(factoryClass); |
89 | ||
90 | 0 | List loaders = new ArrayList(); |
91 | ||
92 | // for compatability reasons, check old TemplatePath setting | |
93 | 0 | if (config.getBooleanSetting("DelegatingTemplateProvider.EmulateTemplatePath", false)) |
94 | { | |
95 | 0 | if (config.getSetting("TemplatePath", "").length() > 0) |
96 | { | |
97 | 0 | TemplateLoader loader = new TemplatePathTemplateLoader(); |
98 | 0 | loader.init(broker, config); |
99 | 0 | loader.setConfig(""); |
100 | 0 | loaders.add(loader); |
101 | } | |
102 | } | |
103 | ||
104 | 0 | int i = 0; |
105 | 0 | String loader = config.getSetting("TemplateLoaderPath.".concat(String.valueOf(i + 1))); |
106 | 0 | while (loader != null) |
107 | { | |
108 | 0 | loaders.add(factory.getTemplateLoader(broker, loader)); |
109 | 0 | i++; |
110 | 0 | loader = config.getSetting("TemplateLoaderPath.".concat(String.valueOf(i + 1))); |
111 | } | |
112 | 0 | templateLoaders = new TemplateLoader[loaders.size()]; |
113 | 0 | loaders.toArray(templateLoaders); |
114 | 0 | } |
115 | ||
116 | public String getType () | |
117 | { | |
118 | 0 | return "template"; |
119 | } | |
120 | ||
121 | /** | |
122 | * Ask all template loaders to load a template from query. | |
123 | * Returns the template from the first provider, that returns a non-null value | |
124 | * or throws a NotFoundException, if all providers return null. | |
125 | */ | |
126 | public Object load (String query, CacheElement ce) throws ResourceException | |
127 | { | |
128 | 0 | for (int i = 0; i < templateLoaders.length; i++) |
129 | { | |
130 | 0 | Template t = templateLoaders[i].load(query, ce); |
131 | 0 | if (t != null) |
132 | { | |
133 | 0 | return t; |
134 | } | |
135 | } | |
136 | 0 | throw new NotFoundException("Could not locate template " + query); |
137 | } | |
138 | ||
139 | /** | |
140 | * Returns an unmodifieable list of this provider's template loaders. | |
141 | * The list is has the same order used for searching templates. You may | |
142 | * use this method to access template loaders and change their settings | |
143 | * at runtime if they have an appropriate method. | |
144 | * @return unmodifieable list of TemplateLoader objects | |
145 | */ | |
146 | public List getTemplateLoaders () | |
147 | { | |
148 | 0 | return Collections.unmodifiableList(Arrays.asList(templateLoaders)); |
149 | } | |
150 | ||
151 | protected TemplateLoaderFactory createFactory (String classname) throws InitException | |
152 | { | |
153 | try | |
154 | { | |
155 | 0 | return (TemplateLoaderFactory) Class.forName(classname).newInstance(); |
156 | } | |
157 | 0 | catch (ClassNotFoundException e) |
158 | { | |
159 | 0 | throw new InitException("Class " + classname + " for template loader factory not found", e); |
160 | } | |
161 | 0 | catch (InstantiationException e) |
162 | { | |
163 | 0 | throw new InitException("Could not instantiate class " + classname + " for template loader factory", e); |
164 | } | |
165 | 0 | catch (IllegalAccessException e) |
166 | { | |
167 | 0 | throw new InitException("Could not instantiate class " + classname + " for template loader facory", e); |
168 | } | |
169 | 0 | catch (ClassCastException e) |
170 | { | |
171 | 0 | throw new InitException("Class " + classname + " for template loader factory does not implement " + |
172 | "interface org.webmacro.resource.TemplateLoaderFactory", e); | |
173 | } | |
174 | } | |
175 | } |