1 package org.apache.velocity.context;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.HashMap;
23 import java.util.Stack;
24
25 import org.apache.velocity.app.event.EventCartridge;
26 import org.apache.velocity.runtime.resource.Resource;
27 import org.apache.velocity.util.introspection.IntrospectionCacheData;
28
29 /**
30 * class to encapsulate the 'stuff' for internal operation of velocity.
31 * We use the context as a thread-safe storage : we take advantage of the
32 * fact that it's a visitor of sorts to all nodes (that matter) of the
33 * AST during init() and render().
34 * Currently, it carries the template name for namespace
35 * support, as well as node-local context data introspection caching.
36 *
37 * Note that this is not a public class. It is for package access only to
38 * keep application code from accessing the internals, as AbstractContext
39 * is derived from this.
40 *
41 * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
42 * @version $Id: InternalContextBase.java 463298 2006-10-12 16:10:32Z henning $
43 */
44 class InternalContextBase implements InternalHousekeepingContext, InternalEventContext
45 {
46 /**
47 * Version Id for serializable
48 */
49 private static final long serialVersionUID = -245905472770843470L;
50
51 /**
52 * cache for node/context specific introspection information
53 */
54 private HashMap introspectionCache = new HashMap(33);
55
56 /**
57 * Template name stack. The stack top contains the current template name.
58 */
59 private Stack templateNameStack = new Stack();
60
61 /**
62 * EventCartridge we are to carry. Set by application
63 */
64 private EventCartridge eventCartridge = null;
65
66 /**
67 * Current resource - used for carrying encoding and other
68 * information down into the rendering process
69 */
70 private Resource currentResource = null;
71
72 /**
73 * Is rendering allowed? Defaults to true, can be changed by #stop directive.
74 */
75 private boolean allowRendering = true;
76
77 /**
78 * set the current template name on top of stack
79 *
80 * @param s current template name
81 */
82 public void pushCurrentTemplateName( String s )
83 {
84 templateNameStack.push(s);
85 }
86
87 /**
88 * remove the current template name from stack
89 */
90 public void popCurrentTemplateName()
91 {
92 templateNameStack.pop();
93 }
94
95 /**
96 * get the current template name
97 *
98 * @return String current template name
99 */
100 public String getCurrentTemplateName()
101 {
102 if ( templateNameStack.empty() )
103 return "<undef>";
104 else
105 return (String) templateNameStack.peek();
106 }
107
108 /**
109 * get the current template name stack
110 *
111 * @return Object[] with the template name stack contents.
112 */
113 public Object[] getTemplateNameStack()
114 {
115 return templateNameStack.toArray();
116 }
117
118 /**
119 * returns an IntrospectionCache Data (@see IntrospectionCacheData)
120 * object if exists for the key
121 *
122 * @param key key to find in cache
123 * @return cache object
124 */
125 public IntrospectionCacheData icacheGet( Object key )
126 {
127 return ( IntrospectionCacheData ) introspectionCache.get( key );
128 }
129
130 /**
131 * places an IntrospectionCache Data (@see IntrospectionCacheData)
132 * element in the cache for specified key
133 *
134 * @param key key
135 * @param o IntrospectionCacheData object to place in cache
136 */
137 public void icachePut( Object key, IntrospectionCacheData o )
138 {
139 introspectionCache.put( key, o );
140 }
141
142 /**
143 * @see org.apache.velocity.context.InternalHousekeepingContext#setCurrentResource(org.apache.velocity.runtime.resource.Resource)
144 */
145 public void setCurrentResource( Resource r )
146 {
147 currentResource = r;
148 }
149
150 /**
151 * @see org.apache.velocity.context.InternalHousekeepingContext#getCurrentResource()
152 */
153 public Resource getCurrentResource()
154 {
155 return currentResource;
156 }
157
158
159 /**
160 * @see org.apache.velocity.context.InternalHousekeepingContext#getAllowRendering()
161 */
162 public boolean getAllowRendering()
163 {
164 return allowRendering;
165 }
166
167 /**
168 * @see org.apache.velocity.context.InternalHousekeepingContext#setAllowRendering(boolean)
169 */
170 public void setAllowRendering(boolean v)
171 {
172 allowRendering = v;
173 }
174
175
176 /**
177 * @see org.apache.velocity.context.InternalEventContext#attachEventCartridge(org.apache.velocity.app.event.EventCartridge)
178 */
179 public EventCartridge attachEventCartridge( EventCartridge ec )
180 {
181 EventCartridge temp = eventCartridge;
182
183 eventCartridge = ec;
184
185 return temp;
186 }
187
188 /**
189 * @see org.apache.velocity.context.InternalEventContext#getEventCartridge()
190 */
191 public EventCartridge getEventCartridge()
192 {
193 return eventCartridge;
194 }
195 }
196