Author: cbrisson
Date: Sat Feb 21 18:54:21 2009
New Revision: 746564
URL: http://svn.apache.org/viewvc?rev=746564&view=rev
Log:
WebappUberspector to allow , and control objets to share their attributes via
standard property getters and setters
Added:
velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/WebappUberspector.java
Modified:
velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/velocity.properties
Added:
velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/WebappUberspector.java
URL:
http://svn.apache.org/viewvc/velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/WebappUberspector.java?rev=746564&view=auto
==============================================================================
---
velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/WebappUberspector.java
(added)
+++
velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/WebappUberspector.java
Sat Feb 21 18:54:21 2009
@@ -0,0 +1,241 @@
+package org.apache.velocity.tools.view;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import org.apache.velocity.util.introspection.*;
+import org.apache.velocity.runtime.parser.node.AbstractExecutor;
+import org.apache.velocity.runtime.parser.node.SetExecutor;
+import org.apache.velocity.runtime.log.Log;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpSession;
+import javax.servlet.ServletContext;
+import java.lang.reflect.InvocationTargetException;
+
+/**
+ * <p>This custom uberspector allows getAttribute() and setAttribute() as
standard
+ * getters and setters for the "request","session" and "application" keys.
+ * <p>It allows VTL statements like:
+ * <pre>
+ * #set($session.foo = 'youpi')
+ * session parameter 'foo' has value: $session.foo
+ * </pre>
+ * </p>
+ * <p>This uberspector requires Velocity 1.6+ ; to use it, you must specify
<code>org.apache.velocity.tools.view.WebappUberspector</code>
+ * as the last uberspector to the <code>runtime.introspector.uberspect</code>
property in you <code>velocity.properties</code> file.</p>
+ *
+ * <p>For instance:</p>
+ *
+ * <p><code>runtime.introspector.uberspect =
org.apache.velocity.util.introspection.UberspectImpl,org.apache.velocity.tools.view.WebappUberspector</code></p>
+ *
+ * @author <a href="mailto:[email protected]";>Claude Brisson</a>
+ * @version $Id: WebappUberspector.java $ */
+
+public class WebappUberspector extends AbstractChainableUberspector
+{
+
+ /**
+ * Property getter
+ * @param obj
+ * @param identifier
+ * @param i
+ * @return A Velocity Getter Method.
+ * @throws Exception
+ */
+ public VelPropertyGet getPropertyGet(Object obj, String identifier, Info i)
+ throws Exception
+ {
+ VelPropertyGet ret = super.getPropertyGet(obj,identifier,i);
+ if(ret == null)
+ {
+ Class claz = obj.getClass();
+ if(obj instanceof HttpServletRequest
+ || obj instanceof HttpSession
+ || obj instanceof ServletContext)
+ {
+ AbstractExecutor executor = new GetAttributeExecutor(log,
introspector, claz, identifier);
+ ret = executor.isAlive() ? new VelGetterImpl(executor) : null;
+ }
+ }
+ return ret;
+ }
+
+ /**
+ * init method
+ * @throws Exception
+ */
+ public void init() throws Exception
+ {
+ super.init();
+ // we need our own introspector since the inner one is hidden by the
Uberspect interface
+ introspector = new Introspector(log);
+ }
+
+ /**
+ * Property setter
+ * @param obj
+ * @param identifier
+ * @param arg
+ * @param i
+ * @return A Velocity Setter method.
+ * @throws Exception
+ */
+ public VelPropertySet getPropertySet(Object obj, String identifier,
+ Object arg, Info i)
+ throws Exception
+ {
+ VelPropertySet ret = super.getPropertySet(obj,identifier,arg,i);
+ if(ret == null) {
+ Class claz = obj.getClass();
+ if(obj instanceof HttpServletRequest
+ || obj instanceof HttpSession
+ || obj instanceof ServletContext)
+ {
+ SetExecutor executor = new SetAttributeExecutor(log,
introspector, claz, arg, identifier);
+ ret = executor.isAlive() ? new VelSetterImpl(executor) : null;
+ }
+ }
+ return ret;
+ }
+
+
+ /**
+ * Executor for getAttribute(name) method.
+ */
+ public class GetAttributeExecutor extends AbstractExecutor
+ {
+ private final Introspector introspector;
+
+ // This is still threadsafe because this object is only read except in
the C'tor.
+ private Object [] params;
+
+ /**
+ * @param log
+ * @param introspector
+ * @param clazz
+ * @param property
+ */
+ public GetAttributeExecutor(final Log log, final Introspector
introspector,
+ final Class clazz, final String property)
+ {
+ this.log = log;
+ this.introspector = introspector;
+ this.params = new Object[] { property };
+
+ discover(clazz);
+ }
+
+ protected void discover(final Class clazz)
+ {
+ try
+ {
+ setMethod(introspector.getMethod(clazz, "getAttribute",
params));
+ }
+ /**
+ * pass through application level runtime exceptions
+ */
+ catch( RuntimeException e )
+ {
+ throw e;
+ }
+ catch(Exception e)
+ {
+ log.error("While looking for getAttribute('" + params[0] + "')
method:", e);
+ }
+ }
+
+ /**
+ * @see
org.apache.velocity.runtime.parser.node.AbstractExecutor#execute(java.lang.Object)
+ */
+ public Object execute(final Object o)
+ throws IllegalAccessException, InvocationTargetException
+ {
+ return isAlive() ? getMethod().invoke(o, params) : null;
+ }
+ }
+
+ /**
+ * Executor for setAttribute(name,value) method
+ */
+ public class SetAttributeExecutor extends SetExecutor
+ {
+ private final Introspector introspector;
+ private final String property;
+
+ /**
+ * @param log
+ * @param introspector
+ * @param clazz
+ * @param arg
+ * @param property
+ */
+ public SetAttributeExecutor(final Log log, final Introspector
introspector,
+ final Class clazz, final Object arg, final String property)
+ {
+ this.log = log;
+ this.introspector = introspector;
+ this.property = property;
+
+ discover(clazz, arg);
+ }
+
+ /**
+ * @param clazz
+ * @param arg
+ */
+ protected void discover(final Class clazz, final Object arg)
+ {
+ Object [] params = new Object[] { property, arg };
+
+ try
+ {
+ setMethod(introspector.getMethod(clazz, "setAttribute",
params));
+ }
+ /**
+ * pass through application level runtime exceptions
+ */
+ catch( RuntimeException e )
+ {
+ throw e;
+ }
+ catch(Exception e)
+ {
+ log.error("While looking for put('" + params[0] + "')
method:", e);
+ }
+ }
+
+ /**
+ * @see
org.apache.velocity.runtime.parser.node.SetExecutor#execute(java.lang.Object,
java.lang.Object)
+ */
+ public Object execute(final Object o, final Object value)
+ throws IllegalAccessException, InvocationTargetException
+ {
+ Object [] params;
+
+ if (isAlive())
+ {
+ params = new Object [] { property, value };
+ return getMethod().invoke(o, params);
+ }
+
+ return null;
+ }
+ }
+}
Modified:
velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/velocity.properties
URL:
http://svn.apache.org/viewvc/velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/velocity.properties?rev=746564&r1=746563&r2=746564&view=diff
==============================================================================
---
velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/velocity.properties
(original)
+++
velocity/tools/trunk/src/main/java/org/apache/velocity/tools/view/velocity.properties
Sat Feb 21 18:54:21 2009
@@ -22,3 +22,8 @@
resource.loader = webapp,string
webapp.resource.loader.class =
org.apache.velocity.tools.view.WebappResourceLoader
string.resource.loader.class =
org.apache.velocity.runtime.resource.loader.StringResourceLoader
+
+# uncomment (or copy in your velocity.properties file) the following line if
you have Velocity 1.6+
+# and want to access application, session and request attributes via standard
setters, like in:
+# #set($session.foo = 'bar') foo is: $session.foo
+#runtime.introspector.uberspect =
org.apache.velocity.util.introspection.UberspectImpl,org.apache.velocity.tools.view.WebappUberspector
