/*
* Copyright (C) 2005 Kepler Project.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package org.keplerproject.luajava.luabsf;
import java.util.Vector;
import org.apache.bsf.BSFDeclaredBean;
import org.apache.bsf.BSFException;
import org.apache.bsf.BSFManager;
import org.apache.bsf.util.BSFEngineImpl;
import org.keplerproject.luajava.LuaException;
import org.keplerproject.luajava.LuaObject;
import org.keplerproject.luajava.LuaState;
import org.keplerproject.luajava.LuaStateFactory;
/**
* This class implements a Engine for bsf to run Lua
*
* @author Thiago Ponte
*/
public class LuaEngine extends BSFEngineImpl
{
/** state used to execute Lua */
private LuaState L;
/**
* This method is used to initialize the engine right after construction.
*/
public void initialize(BSFManager mgr, String lang, Vector declaredBeans)
throws BSFException
{
super.initialize(mgr, lang, declaredBeans);
L = LuaStateFactory.newLuaState();
for (int i = 0; i < declaredBeans.size(); i++)
{
declareBean ((BSFDeclaredBean) declaredBeans.elementAt(i));
}
}
/**
* Terminates the engine.
*/
public void terminate()
{
super.terminate();
L.close();
}
/**
* This is used by an application to execute some script.
*
* @param source (context info) the source of this expression
* (e.g., filename)
* @param lineNo (context info) the line number in source for expr
* @param columnNo (context info) the column number in source for expr
* @param script the script to execute
*/
public void exec(String source, int lineNo, int columnNo, Object script)
throws BSFException
{
if (script instanceof String)
L.doString((String) script);
else if (script instanceof LuaObject)
{
LuaObject obj = (LuaObject) script;
try
{
if(obj.isFunction() || obj.isUserdata() || obj.isTable())
obj.call(new Object[] {});
}
catch(LuaException e)
{
throw new BSFException(e.getMessage());
}
}
}
/**
* This is used by an application to evaluate an expression.
*
* @param source (context info) the source of this expression
* (e.g., filename)
* @param lineNo (context info) the line number in source for expr
* @param columnNo (context info) the column number in source for expr
* @param expr the expression to evaluate
*/
public Object eval(String source, int lineNo, int columnNo, Object expr)
throws BSFException
{
if (expr instanceof String)
{
L.doString("return (" + (String) expr + ")");
try
{
Object obj = L.toJavaObject(-1);
L.pop(1);
return obj;
}
catch (LuaException e)
{
throw new BSFException("Couldn't eval source code at line " + lineNo + " and column " + columnNo);
}
}
else if (expr instanceof LuaObject)
{
LuaObject obj = (LuaObject) expr;
try
{
if(obj.isFunction() || obj.isUserdata() || obj.isTable())
return obj.call(new Object[] {});
}
catch(LuaException e)
{
throw new BSFException("Couldn't eval source code at line " + lineNo + " and column " + columnNo);
}
}
return null;
}
/**
* Only used on OO languages.
*/
public Object call (Object object, String method, Object[] args) throws BSFException
{
return null;
}
/**
* Declare a bean after the engine has been started. Declared beans
* are beans that are named and which the engine must make available
* to the scripts it runs in the most first class way possible.
*
* @param bean bean to declare
*/
public void declareBean (BSFDeclaredBean bean) throws BSFException
{
try
{
L.pushObjectValue(bean.bean);
}
catch (LuaException e)
{
throw new BSFException(e.getMessage());
}
L.setGlobal(bean.name);
}
/**
* Undeclare a previously declared bean.
*
* @param bean the bean to undeclare
*/
public void undeclareBean (BSFDeclaredBean bean) throws BSFException
{
L.pushNil();
L.setGlobal(bean.name);
}
}