/*
* 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.
*/
package org.apache.cocoon.components.flow.javascript;
import java.util.ArrayList;
import java.util.List;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.util.location.Location;
import org.apache.cocoon.util.location.LocationImpl;
import org.apache.cocoon.util.location.LocationUtils;
import org.apache.commons.lang.exception.ExceptionUtils;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.EcmaError;
import org.mozilla.javascript.JavaScriptException;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.debug.DebugFrame;
import org.mozilla.javascript.debug.DebuggableScript;
import org.mozilla.javascript.debug.Debugger;
/**
* A Rhino debugger that tracks location information when an exception is raised in some JavaScript code.
* It's purpose is to build a {@link org.apache.cocoon.ProcessingException} that holds the stacktrace
* in the JavaScript code.
* <p>
* This debugger implementation is designed to be as lightweight and fast as possible, in order to have a
* negligible impact on the performances of the Rhino interpreter.
*
* @since 2.1.8
* @version $Id$
*/
public class LocationTrackingDebugger implements Debugger {
// Strong reference to the location finder
private static final LocationUtils.LocationFinder rhinoLocFinder = new LocationUtils.LocationFinder() {
public Location getLocation(Object obj, String description) {
if (obj instanceof EcmaError) {
EcmaError ex = (EcmaError)obj;
if (ex.getSourceName() != null) {
return new LocationImpl(ex.getName(), ex.getSourceName(), ex.getLineNumber(), ex.getColumnNumber());
} else {
return Location.UNKNOWN;
}
} else if (obj instanceof JavaScriptException) {
JavaScriptException ex = (JavaScriptException)obj;
if (ex.sourceName() != null) {
return new LocationImpl(description, ex.sourceName(), ex.lineNumber(), -1);
} else {
return Location.UNKNOWN;
}
}
return null;
}
};
static {
// Register what's needed to analyze exceptions produced by Rhino
ExceptionUtils.addCauseMethodName("getWrappedException");
LocationUtils.addFinder(rhinoLocFinder);
}
protected List locations;
protected Throwable throwable;
/**
* Rhino+cont API
*/
public void handleCompilationDone(Context cx, DebuggableScript fnOrScript, StringBuffer source) {
// ignore
}
/**
* Rhino+cont API
*/
public DebugFrame enterFrame(Context cx, Scriptable scope, Scriptable thisObj, Object[] args, DebuggableScript fnOrScript) {
return new StackTrackingFrame(fnOrScript);
}
/**
* Rhino 1.6 API
*/
public void handleCompilationDone(Context cx, DebuggableScript fnOrScript, String source) {
// nothing
}
/**
* Rhino 1.6 API
*/
public DebugFrame getFrame(Context cx, DebuggableScript fnOrScript) {
// Rhino 1.6 API
return new StackTrackingFrame(fnOrScript);
}
/**
* Get an exception that reflects the known location stack
*
* @param description a description for the exception
* @param originalException the original exception
*
* @return a suitable exception to throw
* @see ProcessingException#throwLocated(String, Throwable, Location)
*/
public Exception getException(String description, Exception originalException) throws ProcessingException {
if (throwable == null || locations == null) {
// Cannot to better for now
return originalException;
}
// Unwrap original exception, if any, wrapped by Rhino (the wrapping
// class is different in Rhino+cont and Rhino 1.6)
Throwable cause = ExceptionUtils.getCause(throwable);
if (cause != null)
throwable = cause;
return ProcessingException.throwLocated(description, throwable, locations);
}
private class StackTrackingFrame implements DebugFrame {
DebuggableScript script;
int line;
public StackTrackingFrame(DebuggableScript script) {
this.script = script;
}
public void onEnter(Context cx, Scriptable activation, Scriptable thisObj, Object[] args) {
// Rhino 1.6 specific
}
// Rhino+cont API
public void onLineChange(Context cx, int lineNumber, boolean breakpoint) {
line = lineNumber;
}
// Rhino 1.6 API
public void onLineChange(Context cx, int lineNumber) {
line = lineNumber;
}
public void onExceptionThrown(Context cx, Throwable ex) {
throwable = ex;
}
public void onExit(Context cx, boolean byThrow, Object resultOrException) {
if (byThrow) {
String name = null;
// Revisit: Rhino+cont and Rhino 1.6 have different debugger APIs, and we currently don't use this information
// Scriptable obj = script.getScriptable();
// name = obj instanceof NativeFunction ? ((NativeFunction)obj).getFunctionName() : "Top-level script";
// if (name == null || name.length() == 0) {
// name = "[unnamed]";
// }
if (locations == null) {
locations = new ArrayList(1); // start small
}
locations.add(new LocationImpl(name, script.getSourceName(), line, -1));
} else if (locations != null) {
// The exception was handled by the script: clear any recorded locations
locations = null;
}
}
}
}