package org.apache.velocity.runtime.parser.node;
/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Velocity", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
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*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.util.Map;
import java.lang.reflect.Method;
import org.apache.velocity.context.InternalContextAdapter;
import org.apache.velocity.runtime.parser.Parser;
import org.apache.velocity.util.introspection.IntrospectionCacheData;
import org.apache.velocity.util.introspection.Introspector;
import org.apache.velocity.runtime.RuntimeConstants;
import org.apache.velocity.exception.MethodInvocationException;
import java.lang.reflect.InvocationTargetException;
/**
* ASTIdentifier.java
*
* Method support for identifiers : $foo
*
* mainly used by ASTRefrence
*
* Introspection is now moved to 'just in time' or at render / execution
* time. There are many reasons why this has to be done, but the
* primary two are thread safety, to remove any context-derived
* information from class member variables.
*
* @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
* @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
* @version $Id: ASTIdentifier.java,v 1.16 2001/11/19 13:53:08 geirm Exp $
*/
public class ASTIdentifier extends SimpleNode
{
private String identifier = "";
public ASTIdentifier(int id)
{
super(id);
}
public ASTIdentifier(Parser p, int id)
{
super(p, id);
}
/** Accept the visitor. **/
public Object jjtAccept(ParserVisitor visitor, Object data)
{
return visitor.visit(this, data);
}
/**
* simple init - don't do anything that is context specific.
* just get what we need from the AST, which is static.
*/
public Object init( InternalContextAdapter context, Object data)
throws Exception
{
super.init( context, data );
identifier = getFirstToken().image;
return data;
}
/**
* introspects the class to find the method name of the node,
* or if that fails, treats the reference object as a map
* and treats the identifier as a key in that map.
* This needs work.
*
* @param data Class to be introspected
*/
private AbstractExecutor doIntrospection( Class data )
throws Exception
{
AbstractExecutor executor;
/*
* first try for a getFoo() type of property
* (also getfoo() )
*/
executor = new PropertyExecutor(rsvc, data, identifier);
/*
* if that didn't work, look for get("foo")
*/
if (executor.isAlive() == false)
{
executor = new GetExecutor( rsvc, data, identifier);
}
/*
* finally, look for boolean isFoo()
*/
if( executor.isAlive() == false)
{
executor = new BooleanPropertyExecutor( rsvc, data, identifier );
}
return executor;
}
/**
* invokes the method on the object passed in
*/
public Object execute(Object o, InternalContextAdapter context)
throws MethodInvocationException
{
AbstractExecutor executor = null;
try
{
Class c = o.getClass();
/*
* first, see if we have this information cached.
*/
IntrospectionCacheData icd = context.icacheGet( this );
/*
* if we have the cache data and the class of the object we are
* invoked with is the same as that in the cache, then we must
* be allright. The last 'variable' is the method name, and
* that is fixed in the template :)
*/
if ( icd != null && icd.contextData == c )
{
executor = ( AbstractExecutor ) icd.thingy;
}
else
{
/*
* otherwise, do the introspection, and cache it
*/
executor = doIntrospection( c );
if (executor != null)
{
icd = new IntrospectionCacheData();
icd.contextData = c;
icd.thingy = executor;
context.icachePut( this, icd );
}
}
}
catch( Exception e)
{
rsvc.error("ASTIdentifier.execute() : identifier = "
+ identifier + " : " + e );
}
/*
* we have no executor... punt...
*/
if (executor == null)
{
return null;
}
/*
* now try and execute. If we get a MIE, throw that
* as the app wants to get these. If not, log and punt.
*/
try
{
return executor.execute(o, context);
}
catch( MethodInvocationException mie )
{
throw mie;
}
catch( Exception e )
{
rsvc.error("ASTIdentifier() : exception invoking method for identifier '"
+ identifier + "' in " + o.getClass() + " : " + e );
}
return null;
}
}