function set_exception_handler (callback) {

// http://kevin.vanzonneveld.net

// + original by: Brett Zamir (http://brett-zamir.me)

// * example 1: set_exception_handler(function (exceptionObj) {alert(exceptionObj.getMessage());});

// * returns 1: null

var that = this, oldHandlerName = '';

var _getFuncName = function (fn) {

var name = (/\W*function\s+([\w\$]+)\s*\(/).exec(fn);

if (!name) {

return '(Anonymous)';

}

return name[1];

};

if (typeof callback === 'string') {

callback = this.window[callback];

}

// BEGIN REDUNDANT

this.php_js = this.php_js || {};

// END REDUNDANT

// For return

oldHandlerName = this.php_js.exception_handler ? _getFuncName(this.php_js.exception_handler) : null;

if (this.php_js.exception_handler) { // Fix: Any potential built-in ones (e.g., via ini) to fall back on, as the PHP manual suggests?

this.php_js.previous_exception_handler = this.php_js.exception_handler; // usable by restore_exception_handler()

}

// Set callback

this.php_js.exception_handler = callback;

// Make available a global Exception class (see _experimental/language)

if (!this.window.Exception) {

this.window.Exception = function (message, code) {

// These four are supposed to be protected (extendable, but not public)

this.message = message || '';

this.code = code || 0; // user defined exception code

// Fix: Just putting something here for the next two (not PHP-style)... Can over-ride if extending, however;

// in Mozilla, error objects (e.g., if you're in a catch block), have these properties which might be used to

// add to the object after instantiation (or during instantiation if extending the exception): fileName,

// lineNumber, stack; actually, should use PHP Error object for these anyways if following the PHP API

// since it does have these properties

// Note that for the trace, however, in Mozilla the stack property is a string, and getTrace() needs the items

// parsed as an array; this might be doable by setting the exception object's trace property to

// "e.stack.replace(/\n$/, '').split('\n');" if 'e' is a JavaScript exception

this.file = this.window.href.location; // source filename of exception

this.line = 0; // source line of exception

this.string = 'Exception'; // private string; Internal Exception name

this.name = 'Exception'; // To fit the JavaScript Error interface, user could also add a custom name property.

that.php_js.exception_handler(this);

};

this.window.Exception.prototype = {

constructor: this.window.Exception,

// FINAL (not supposed to extend the following 6 methods)

getMessage : function () { // message of exception

return this.message;

},

getCode : function () { // code of exception

return this.code;

},

getFile : function () { // source filename

return this.file;

},

getLine : function () { // source line

return this.line;

},

getTrace : function () { // an array of the backtrace()

// Todo: add trace for Mozilla, etc.

var ret = '';

for (var i=0; i < this.trace.length; i++) {

ret += '\n#'+i+' '+this.trace[i];

}

return ret.slice(1);

// return this.trace; // should be an array (especially so that getTraceAsString() works properly)

},

getTraceAsString : function () { // formatted string of trace

// Todo: add trace for Mozilla, etc.

return this.trace.toString();

},

// Overrideable

__toString : function () { // formatted string for display

// PHP-style

return "exception '"+this.string+"' with message '"+this.getMessage()+"' in "+

this.getFile()+":"+this.getLine()+"\nStack trace:\n"+this.getTraceAsString();

// return this.name+': '+this.message; // this works also, but in JavaScript-style

},

// For JavaScript interface/behavior:

toString : function () {

return this.__toString(); // We implement on toString() to implement JavaScript Error interface

},

// PRIVATE FINAL METHODS

__clone : function () {

throw 'Fatal exception: exceptions are not clonable';

}

};

}

return oldHandlerName;

}