phpjs/functions/var/is_resource.js

php.js offers community built php functions in javascript

function is_resource(handle) {
  //  discuss at: http://phpjs.org/functions/is_resource/
  // original by: Brett Zamir (http://brett-zamir.me)
  // improved by: Luis Salazar (http://www.freaky-media.com/)
  //   example 1: is_resource('a');
  //   returns 1: false

  var getFuncName = function(fn) {
    var name = (/\W*function\s+([\w\$]+)\s*\(/)
      .exec(fn);
    if (!name) {
      return '(Anonymous)';
    }
    return name[1];
  };
  return !(!handle || typeof handle !== 'object' || !handle.constructor || getFuncName(handle.constructor) !==
    'PHPJS_Resource');
}