package org.apache.bsf.engines.javascript;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import javax.script.Compilable;
import javax.script.CompiledScript;
import javax.script.GenericScriptEngine;
import javax.script.Invocable;
import javax.script.Namespace;
import javax.script.ScriptContext;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptException;
import org.apache.bsf.util.BSFInvocation;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.EvaluatorException;
import org.mozilla.javascript.Function;
import org.mozilla.javascript.JavaScriptException;
import org.mozilla.javascript.NativeJavaObject;
import org.mozilla.javascript.Script;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.Undefined;
import org.mozilla.javascript.WrappedException;
/**
* This is interface to Netscape's Rhino (JavaScript) form Web Scripting
* Framework.
* NOTE : Some of the code were taken form JavaScript engine used in
* Jakarta Apache Beans Scritping Framework.
*
* @author Nandika Jayawardana <nandika@opensource.lk>
* @author Sanka Samaranayake <sanka@opensource.lk>
*/
public class RhinoScriptEngine extends GenericScriptEngine implements Compilable, Invocable{
private RhinoNamespaceBridge rhinospace;
private BSFInvocation invoker;
/**
* Constructs an instance of RhinoScriptEngine.
*/
public RhinoScriptEngine(){
super();
// setting up the Engine Namespace ..
rhinospace = new RhinoNamespaceBridge(this);
invoker = new BSFInvocation(this);
}
public RhinoScriptEngine(Namespace namespace){
super(namespace);
rhinospace = new RhinoNamespaceBridge(this);
}
public Object call(String methodName, Object thiz, Object[] args)
throws ScriptException {
Context cx;
Scriptable scope;
Object retValue = null;
if (thiz != null && !(thiz instanceof Scriptable)) {
throw new IllegalArgumentException(thiz
+ " is not a valid JavaScript object");
}
scope = (thiz == null) ? rhinospace : (Scriptable) thiz;
try {
cx = Context.enter();
Object func = scope.get(methodName, scope);
if (func == null || !(func instanceof Function)) {
throw new EvaluatorException("Function " + methodName
+ " not found");
}
cx.setGeneratingDebug(false);
cx.setGeneratingSource(false);
cx.setOptimizationLevel(-1);
retValue = ((Function) func).call(cx, scope,
(Scriptable) thiz, args);
} catch (Throwable throwable) {
errorHandler(throwable);
} finally {
Context.exit();
}
return unwrap(retValue);
}
public Object call(String methodName, Object[] args)
throws ScriptException {
return call(methodName, null, args);
}
public CompiledScript compile(Reader reader) throws ScriptException {
Context cx;
Script script = null;
try {
cx = Context.enter();
String source =
((String) rhinospace.get("javax.script.filename") != null)
? (String) rhinospace.get("javax.script.filename")
: "<unknown>";
script = cx.compileReader(reader, source, 0, null);
} catch (Throwable throwable) {
errorHandler(throwable);
} finally {
Context.exit();
}
return new RhinoCompiledScript(script, this);
}
public CompiledScript compile(String script) throws ScriptException {
return compile(new StringReader(script));
}
public Namespace createNamespace(){
return new RhinoNamespaceBridge(this);
}
public Object eval(Reader reader, ScriptContext context)
throws ScriptException{
Context cx;
Object retVal = null;
RhinoNamespaceBridge oldSpace = rhinospace;
String source = (get("javax.script.filename") != null)
? get("javax.script.filename").toString()
: "<unknown>";
try {
cx = Context.enter();
cx.setGeneratingDebug(false);
cx.setGeneratingSource(false);
cx.setOptimizationLevel(-1);
Scriptable sc = getScope(context);
retVal = cx.evaluateReader(sc, reader, source, 0, null);
} catch (JavaScriptException ex) {
errorHandler(ex);
} catch (IOException ioe) {
errorHandler(ioe);
} finally {
rhinospace = oldSpace;
Context.exit();
}
return unwrap(retVal);
}
public Object eval(String script, ScriptContext context)
throws ScriptException {
return eval(new StringReader(script), context);
}
public ScriptEngineFactory getFactory() {
return new RhinoScriptEngineFactory();
}
public Object getInterface(Class clasz) {
return invoker.getInterface(clasz);
}
public Object unwrap(Object value){
value = (value instanceof NativeJavaObject) ?
((NativeJavaObject)value).unwrap() : value;
return !(value instanceof Undefined) ? value : null;
}
public Scriptable getScope(ScriptContext context){
RhinoNamespaceBridge targetScope;
Namespace enginespace = context.getNamespace(ScriptContext.ENGINE_SCOPE),
globalsapce = context.getNamespace(ScriptContext.GLOBAL_SCOPE);
if (enginespace != null && enginespace != rhinospace) {
if (enginespace instanceof RhinoNamespaceBridge) {
targetScope = (RhinoNamespaceBridge)enginespace;
} else {
targetScope = new RhinoNamespaceBridge(enginespace);
}
} else {
targetScope = rhinospace;
}
if (globalspace != null) {
targetScope.setGlobalNamespace(globalspace);
}
targetScope.put("context", context);
return targetScope;
}
public void errorHandler(Throwable throwable) throws ScriptException{
String message = null;
String source = null;
int lineNumber = -1;
int columnNumber = -1;
// gets the wrapped exception if the argument is a wrapper
if(throwable instanceof WrappedException){
throwable = ((WrappedException)throwable).getWrappedException();
}
/*
if(throwable instanceof JavaScriptException){
message = throwable.getLocalizedMessage();
source = ((JavaScriptException)throwable).getSourceName();
if(((JavaScriptException)throwable).getLineNumber() != 0){
lineNumber = ((JavaScriptException)throwable).getLineNumber();
}
}else if(throwable instanceof EvaluatorException){
message = ((EvaluatorException)throwable).getLocalizedMessage();
source = ((EvaluatorException)throwable).getSourceName();
if(((EvaluatorException)throwable).getLineNumber() != 0){
lineNumber = ((EvaluatorException)throwable).getLineNumber();
}
if(((EvaluatorException)throwable).getColumnNumber() != 0){
columnNumber = ((EvaluatorException)throwable).getColumnNumber();
}
}else if(throwable instanceof StackOverflowError){
message = "STACK OVERFLOW :";
}
*/
if(message == null){
message = throwable.toString();
}
if(throwable instanceof Error &&
!(throwable instanceof StackOverflowError)){
throw (Error)throwable;
}else{
throw new ScriptException(message, source, lineNumber, columnNumber);
}
}
}