/*
* Copyright 2004,2004 The Apache Software Foundation.
*
* Licensed 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.
*/
package org.apache.bsf.engines.jacl;
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 tcl.lang.Interp;
import tcl.lang.ReflectObject;
import tcl.lang.TclDouble;
import tcl.lang.TclException;
import tcl.lang.TclInteger;
import tcl.lang.TclObject;
import tcl.lang.TclString;
/**
* This is the interface to Scriptics's Jacl (Tcl) from the
* Bean Scripting Framework.
* <p>
*
* @author Sanjiva Weerawarana
*/
public class JaclEngine extends BSFEngineImpl {
/* the Jacl interpretor object */
private Interp interp;
/**
*
* @param method The name of the method to call.
* @param args an array of arguments to be
* passed to the extension, which may be either
* Vectors of Nodes, or Strings.
*/
public Object call (Object obj, String method, Object[] args)
throws BSFException {
StringBuffer tclScript = new StringBuffer (method);
if (args != null) {
for( int i = 0 ; i < args.length ; i++ ) {
tclScript.append (" ");
tclScript.append (args[i].toString ());
}
}
return eval ("<function call>", 0, 0, tclScript.toString ());
}
/**
* Declare a bean
*/
public void declareBean (BSFDeclaredBean bean) throws BSFException {
String expr = "set " + bean.name + " [bsf lookupBean \"" + bean.name +
"\"]";
eval ("<declare bean>", 0, 0, expr);
}
/**
* This is used by an application to evaluate a string containing
* some expression.
*/
public Object eval (String source, int lineNo, int columnNo,
Object oscript) throws BSFException {
String script = oscript.toString ();
try {
interp.eval (script);
TclObject result = interp.getResult();
Object internalRep = result.getInternalRep();
// if the object has a corresponding Java type, unwrap it
if (internalRep instanceof ReflectObject)
return ReflectObject.get(interp,result);
if (internalRep instanceof TclString)
return result.toString();
if (internalRep instanceof TclDouble)
return new Double(TclDouble.get(interp,result));
if (internalRep instanceof TclInteger)
return new Integer(TclInteger.get(interp,result));
return result;
} catch (TclException e) {
throw new BSFException (BSFException.REASON_EXECUTION_ERROR,
"error while eval'ing Jacl expression: " +
interp.getResult (), e);
}
}
/**
* Initialize the engine.
*/
public void initialize (BSFManager mgr, String lang,
Vector declaredBeans) throws BSFException {
super.initialize (mgr, lang, declaredBeans);
// create interpreter
interp = new Interp();
// register the extension that user's can use to get at objects
// registered by the app
interp.createCommand ("bsf", new BSFCommand (mgr, this));
// Make java functions be available to Jacl
try {
interp.eval("jaclloadjava");
} catch (TclException e) {
throw new BSFException (BSFException.REASON_OTHER_ERROR,
"error while loading java package: " +
interp.getResult (), e);
}
int size = declaredBeans.size ();
for (int i = 0; i < size; i++) {
declareBean ((BSFDeclaredBean) declaredBeans.elementAt (i));
}
}
/**
* Undeclare a previously declared bean.
*/
public void undeclareBean (BSFDeclaredBean bean) throws BSFException {
eval ("<undeclare bean>", 0, 0, "set " + bean.name + " \"\"");
}
}