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
24 import org.apache.velocity.runtime.RuntimeServices;
25 import org.apache.velocity.runtime.RuntimeConstants;
26 import org.apache.velocity.runtime.directive.VMProxyArg;
27 import org.apache.velocity.util.introspection.IntrospectionCacheData;
28 import org.apache.velocity.runtime.resource.Resource;
29 import org.apache.velocity.app.event.EventCartridge;
30 import org.apache.velocity.exception.MethodInvocationException;
31
32 /**
33 * This is a special, internal-use-only context implementation to be
34 * used for the new Velocimacro implementation.
35 *
36 * The main distinguishing feature is the management of the VMProxyArg objects
37 * in the put() and get() methods.
38 *
39 * Further, this context also supports the 'VM local context' mode, where
40 * any put() of references that aren't args to the VM are considered
41 * local to the vm, protecting the global context.
42 *
43 * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
44 * @version $Id: VMContext.java 471908 2006-11-06 22:39:28Z henning $
45 */
46 public class VMContext implements InternalContextAdapter
47 {
48 /** container for our VMProxy Objects */
49 HashMap vmproxyhash = new HashMap();
50
51 /** container for any local or constant VMProxy items */
52 HashMap localcontext = new HashMap();
53
54 /** the base context store. This is the 'global' context */
55 InternalContextAdapter innerContext = null;
56
57 /** context that we are wrapping */
58 InternalContextAdapter wrappedContext = null;
59
60 /** support for local context scope feature, where all references are local */
61 private boolean localcontextscope = false;
62
63 /**
64 * CTOR, wraps an ICA
65 * @param inner
66 * @param rsvc
67 */
68 public VMContext( InternalContextAdapter inner, RuntimeServices rsvc )
69 {
70 localcontextscope = rsvc.getBoolean( RuntimeConstants.VM_CONTEXT_LOCALSCOPE, false );
71
72 wrappedContext = inner;
73 innerContext = inner.getBaseContext();
74 }
75
76 /**
77 * Return the inner / user context.
78 * @return The inner / user context.
79 */
80 public Context getInternalUserContext()
81 {
82 return innerContext.getInternalUserContext();
83 }
84
85 /**
86 * @see org.apache.velocity.context.InternalWrapperContext#getBaseContext()
87 */
88 public InternalContextAdapter getBaseContext()
89 {
90 return innerContext.getBaseContext();
91 }
92
93 /**
94 * Used to put VMProxyArgs into this context. It separates
95 * the VMProxyArgs into constant and non-constant types
96 * pulling out the value of the constant types so they can
97 * be modified w/o damaging the VMProxyArg, and leaving the
98 * dynamic ones, as they modify context rather than their own
99 * state
100 * @param vmpa VMProxyArg to add
101 * @throws MethodInvocationException
102 */
103 public void addVMProxyArg( VMProxyArg vmpa ) throws MethodInvocationException
104 {
105 /*
106 * ask if it's a constant : if so, get the value and put into the
107 * local context, otherwise, put the vmpa in our vmproxyhash
108 */
109
110 String key = vmpa.getContextReference();
111
112 if ( vmpa.isConstant() )
113 {
114 localcontext.put( key, vmpa.getObject( wrappedContext ) );
115 }
116 else
117 {
118 vmproxyhash.put( key, vmpa );
119 }
120 }
121
122 /**
123 * Impl of the Context.put() method.
124 *
125 * @param key name of item to set
126 * @param value object to set to key
127 * @return old stored object
128 */
129 public Object put(final String key, final Object value)
130 {
131 return put(key, value, localcontextscope);
132 }
133
134 /**
135 * Allows callers to explicitly put objects in the local context,
136 * no matter what the velocimacro.context.local setting says. Needed
137 * e.g. for loop variables in foreach.
138 *
139 * @param key name of item to set.
140 * @param value object to set to key.
141 * @return old stored object
142 */
143 public Object localPut(final String key, final Object value)
144 {
145 return put(key, value, true);
146 }
147
148 /**
149 * Internal put method to select between local and global scope.
150 *
151 * @param key name of item to set
152 * @param value object to set to key
153 * @param forceLocal True forces the object into the local scope.
154 * @return old stored object
155 */
156 protected Object put(final String key, final Object value, final boolean forceLocal)
157 {
158 /*
159 * first see if this is a vmpa
160 */
161
162 VMProxyArg vmpa = (VMProxyArg) vmproxyhash.get( key );
163
164 if( vmpa != null)
165 {
166 return vmpa.setObject( wrappedContext, value );
167 }
168 else
169 {
170 if(forceLocal)
171 {
172 /*
173 * just put in the local context
174 */
175 return localcontext.put(key, value);
176 }
177 else
178 {
179 /*
180 * ok, how about the local context?
181 */
182
183 if (localcontext.containsKey(key))
184 {
185 return localcontext.put(key, value);
186 }
187 else
188 {
189 /*
190 * otherwise, let them push it into the 'global' context
191 */
192
193 return innerContext.put(key, value);
194 }
195 }
196 }
197 }
198
199 /**
200 * Impl of the Context.gut() method.
201 *
202 * @param key name of item to get
203 * @return stored object or null
204 */
205 public Object get( String key )
206 {
207 /*
208 * first, see if it's a VMPA
209 */
210
211 Object o = null;
212
213 VMProxyArg vmpa = (VMProxyArg) vmproxyhash.get( key );
214
215 if( vmpa != null )
216 {
217 o = vmpa.getObject( wrappedContext );
218 }
219 else
220 {
221 /*
222 * always try the local context then innerContext--even if localcontextscope
223 */
224
225 o = localcontext.get( key );
226
227 if ( o == null)
228 {
229 /*
230 * last chance
231 */
232
233 o = innerContext.get( key );
234 }
235 }
236
237 return o;
238 }
239
240 /**
241 * @see org.apache.velocity.context.Context#containsKey(java.lang.Object)
242 */
243 public boolean containsKey(Object key)
244 {
245 return false;
246 }
247
248 /**
249 * @see org.apache.velocity.context.Context#getKeys()
250 */
251 public Object[] getKeys()
252 {
253 return vmproxyhash.keySet().toArray();
254 }
255
256 /**
257 * @see org.apache.velocity.context.Context#remove(java.lang.Object)
258 */
259 public Object remove(Object key)
260 {
261 return vmproxyhash.remove( key );
262 }
263
264 /**
265 * @see org.apache.velocity.context.InternalHousekeepingContext#pushCurrentTemplateName(java.lang.String)
266 */
267 public void pushCurrentTemplateName( String s )
268 {
269 innerContext.pushCurrentTemplateName( s );
270 }
271
272 /**
273 * @see org.apache.velocity.context.InternalHousekeepingContext#popCurrentTemplateName()
274 */
275 public void popCurrentTemplateName()
276 {
277 innerContext.popCurrentTemplateName();
278 }
279
280 /**
281 * @see org.apache.velocity.context.InternalHousekeepingContext#getCurrentTemplateName()
282 */
283 public String getCurrentTemplateName()
284 {
285 return innerContext.getCurrentTemplateName();
286 }
287
288 /**
289 * @see org.apache.velocity.context.InternalHousekeepingContext#getTemplateNameStack()
290 */
291 public Object[] getTemplateNameStack()
292 {
293 return innerContext.getTemplateNameStack();
294 }
295
296 /**
297 * @see org.apache.velocity.context.InternalHousekeepingContext#icacheGet(java.lang.Object)
298 */
299 public IntrospectionCacheData icacheGet( Object key )
300 {
301 return innerContext.icacheGet( key );
302 }
303
304 /**
305 * @see org.apache.velocity.context.InternalHousekeepingContext#icachePut(java.lang.Object, org.apache.velocity.util.introspection.IntrospectionCacheData)
306 */
307 public void icachePut( Object key, IntrospectionCacheData o )
308 {
309 innerContext.icachePut( key, o );
310 }
311
312 /**
313 * @see org.apache.velocity.context.InternalHousekeepingContext#getAllowRendering()
314 */
315 public boolean getAllowRendering()
316 {
317 return innerContext.getAllowRendering();
318 }
319
320 /**
321 * @see org.apache.velocity.context.InternalHousekeepingContext#setAllowRendering(boolean)
322 */
323 public void setAllowRendering(boolean v)
324 {
325 innerContext.setAllowRendering(v);
326 }
327
328 /**
329 * @see org.apache.velocity.context.InternalEventContext#attachEventCartridge(org.apache.velocity.app.event.EventCartridge)
330 */
331 public EventCartridge attachEventCartridge( EventCartridge ec )
332 {
333 EventCartridge cartridge = innerContext.attachEventCartridge( ec );
334 return cartridge;
335 }
336
337 /**
338 * @see org.apache.velocity.context.InternalEventContext#getEventCartridge()
339 */
340 public EventCartridge getEventCartridge()
341 {
342 return innerContext.getEventCartridge();
343 }
344
345
346 /**
347 * @see org.apache.velocity.context.InternalHousekeepingContext#setCurrentResource(org.apache.velocity.runtime.resource.Resource)
348 */
349 public void setCurrentResource( Resource r )
350 {
351 innerContext.setCurrentResource( r );
352 }
353
354 /**
355 * @see org.apache.velocity.context.InternalHousekeepingContext#getCurrentResource()
356 */
357 public Resource getCurrentResource()
358 {
359 return innerContext.getCurrentResource();
360 }
361 }
362
363
364