util.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 
  var util = {};
  
  util.urlParam = function(name)
  {
	var results = new RegExp('[\\?&]' + name + '=([^&#]*)').exec(window.location.href);
	if (!results) { return undefined; }
	return unescape(results[1] || undefined);
  };

  util.assert = function (cond) {
    if (! cond) {
      var args = ["Assertion error:"].concat(Array.prototype.slice.call(arguments, 1));
      console.error.apply(console, args);
      if (console.trace) {
        console.trace();
      }
      throw new Error(args.join(" "));
    }
  };   

  util.extend = function (base, extensions) {
    if (! extensions) {
      extensions = base;
      base = {};
    }
    for (var a in extensions) {
      if (extensions.hasOwnProperty(a)) {
        base[a] = extensions[a];
      }
    }
    return base;
  };
  
  util.Class = function (superClass, prototype) {
    var a;
    if (prototype === undefined) {
      prototype = superClass;
    } else {
      if (superClass.prototype) {
        superClass = superClass.prototype;
      }
      var newPrototype = Object.create(superClass);
      for (a in prototype) {
        if (prototype.hasOwnProperty(a)) {
          newPrototype[a] = prototype[a];
        }
      }
      prototype = newPrototype;
    }
    var ClassObject = function () {
      var obj = Object.create(prototype);
      obj.constructor.apply(obj, arguments);
      obj.constructor = ClassObject;
      return obj;
    };
    ClassObject.prototype = prototype;
    if (prototype.constructor.name) {
      ClassObject.className = prototype.constructor.name;
      ClassObject.toString = function () {
        return '[Class ' + this.className + ']';
      };
    }
    if (prototype.classMethods) {
      for (a in prototype.classMethods) {
        if (prototype.classMethods.hasOwnProperty(a)) {
          ClassObject[a] = prototype.classMethods[a];
        }
      }
    }
    return ClassObject;
  };