protoclass.js

/* Based on Alex Arnell's inheritance implementation. */
var Class = {
  create: function() {
    var parent = null, properties = $A(arguments);
    if (Object.isFunction(properties[0]))
      parent = properties.shift();

    function klass() {
      this.initialize.apply(this, arguments);
    }

    Object.extend(klass, Class.Methods);
    klass.superclass = parent;
    klass.subclasses = [];

    if (parent) {
      var subclass = function() { };
      subclass.prototype = parent.prototype;
      klass.prototype = new subclass;
      parent.subclasses.push(klass);
    }

    for (var i = 0; i < properties.length; i++)
      klass.addMethods(properties[i]);

    if (!klass.prototype.initialize)
      klass.prototype.initialize = this.emptyFunction;

    klass.prototype.constructor = klass;

    return klass;
  },
  emptyFunction:function () {},

};

Class.Methods = {
  addMethods: function(source) {
    var ancestor   = this.superclass && this.superclass.prototype;
    var properties = Object.keys(source);

    if (!Object.keys({ toString: true }).length)
      properties.push("toString", "valueOf");

    for (var i = 0, length = properties.length; i < length; i++) {
      var property = properties[i], value = source[property];
      if (ancestor && Object.isFunction(value) &&
          value.argumentNames().first() == "$super") {
        var method = value, value = Object.extend((function(m) {
          return function() { return ancestor[m].apply(this, arguments) };
        })(property).wrap(method), {
          valueOf:  function() { return method },
          toString: function() { return method.toString() }
        });
      }
      this.prototype[property] = value;
    }

    return this;
  }
};

Object.extend = function(destination, source) {
  for (var property in source)
    destination[property] = source[property];
  return destination;
};

Object.extend(Object, {
  inspect: function(object) {
    try {
      if (Object.isUndefined(object)) return 'undefined';
      if (object === null) return 'null';
      return object.inspect ? object.inspect() : String(object);
    } catch (e) {
      if (e instanceof RangeError) return '...';
      throw e;
    }
  },

  toJSON: function(object) {
    var type = typeof object;
    switch (type) {
      case 'undefined':
      case 'function':
      case 'unknown': return;
      case 'boolean': return object.toString();
    }

    if (object === null) return 'null';
    if (object.toJSON) return object.toJSON();
    if (Object.isElement(object)) return;

    var results = [];
    for (var property in object) {
      var value = Object.toJSON(object[property]);
      if (!Object.isUndefined(value))
        results.push(property.toJSON() + ': ' + value);
    }

    return '{' + results.join(', ') + '}';
  },

  toQueryString: function(object) {
    return $H(object).toQueryString();
  },

  toHTML: function(object) {
    return object && object.toHTML ? object.toHTML() : String.interpret(object);
  },

  keys: function(object) {
    var keys = [];
    for (var property in object)
      keys.push(property);
    return keys;
  },

  values: function(object) {
    var values = [];
    for (var property in object)
      values.push(object[property]);
    return values;
  },

  clone: function(object) {
    return Object.extend({ }, object);
  },

  isElement: function(object) {
    return object && object.nodeType == 1;
  },

  isArray: function(object) {
    return object != null && typeof object == "object" &&
      'splice' in object && 'join' in object;
  },

  isHash: function(object) {
    return object instanceof Hash;
  },

  isFunction: function(object) {
    return typeof object == "function";
  },

  isString: function(object) {
    return typeof object == "string";
  },

  isNumber: function(object) {
    return typeof object == "number";
  },

  isUndefined: function(object) {
    return typeof object == "undefined";
  }
});

function $A(iterable) {
  if (!iterable) return [];
  if (iterable.toArray) return iterable.toArray();
  var length = iterable.length || 0, results = new Array(length);
  while (length--) results[length] = iterable[length];
  return results;
}

if (WebKit = navigator.userAgent.indexOf('AppleWebKit/') > -1) {
  $A = function(iterable) {
    if (!iterable) return [];
    if (!(Object.isFunction(iterable) && iterable == '[object NodeList]') &&
        iterable.toArray) return iterable.toArray();
    var length = iterable.length || 0, results = new Array(length);
    while (length--) results[length] = iterable[length];
    return results;
  };
}