phpjs/experimental/runkit/runkit_method_redefine.js

php.js offers community built php functions in javascript

function runkit_method_redefine(classname, methodname, args, code, flags) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: runkit_method_redefine('someClass', 'someMethod', 'a,b', 'return a+b');
  // *     returns 1: true
  // In JavaScript, this is identical to runkit_method_add
  var argmnts = [],
      func;
  var getFuncName = function(fn) {
    var name = (/\W*function\s+([\w\$]+)\s*\(/).exec(fn);
    if (!name) {
      return '(Anonymous)';
    }
    return name[1];
  };

  switch (flags) {
    case 'RUNKIT_ACC_PROTECTED':
      throw 'Protected not supported';
    case 'RUNKIT_ACC_PRIVATE':
      throw 'Private not supported';
    case 'RUNKIT_ACC_PUBLIC':
    default:
      break;
  }

  argmnts = args.split(/,\s*/);

  if (typeof classname === 'string') {
    classname = this.window[classname];
  }

  if (getFuncName(classname) !== 'PHP_JS' || // By default, don't allow overriding of PHP functions
      (this.php_js && this.php_js.ini && this.php_js.ini['runkit.internal_override'] && (this.php_js.ini['runkit.internal_override'].local_value === true || this.php_js.ini['runkit.internal_override'].local_value === 1 || this.php_js.ini['runkit.internal_override'].local_value === '1' || this.php_js.ini['runkit.internal_override'].local_value === 'true'))) {
    // Could use the following to add as a static method to the class
    //        func = Function.apply(null, argmnts.concat(code));
    //            classname[methodname] = func;
    func = Function.apply(null, argmnts.concat(code));
    classname.prototype[methodname] = func;
    return true;
  }
  return false;
}