packer-cn/website/source/assets/javascripts/lib/Base.js

/*
  Based on Base.js 1.1a (c) 2006-2010, Dean Edwards
  Updated to pass JSHint and converted into a module by Kenneth Powers
  License: http://www.opensource.org/licenses/mit-license.php
*/
/*global define:true module:true*/
/*jshint eqeqeq:true*/
(function (name, global, definition) {
  if (typeof module !== 'undefined') {
    module.exports = definition();
  } else if (typeof define !== 'undefined' && typeof define.amd === 'object') {
    define(definition);
  } else {
    global[name] = definition();
  }
})('Base', this, function () {
  // Base Object
  var Base = function () {};

  // Implementation
  Base.extend = function (_instance, _static) { // subclass
    var extend = Base.prototype.extend;
    // build the prototype
    Base._prototyping = true;
    var proto = new this();
    extend.call(proto, _instance);
    proto.base = function () {
      // call this method from any other method to invoke that method's ancestor
    };
    delete Base._prototyping;
    // create the wrapper for the constructor function
    //var constructor = proto.constructor.valueOf(); //-dean
    var constructor = proto.constructor;
    var klass = proto.constructor = function () {
        if (!Base._prototyping) {
          if (this._constructing || this.constructor === klass) { // instantiation
            this._constructing = true;
            constructor.apply(this, arguments);
            delete this._constructing;
          } else if (arguments[0] !== null) { // casting
            return (arguments[0].extend || extend).call(arguments[0], proto);
          }
        }
      };
    // build the class interface
    klass.ancestor = this;
    klass.extend = this.extend;
    klass.forEach = this.forEach;
    klass.implement = this.implement;
    klass.prototype = proto;
    klass.toString = this.toString;
    klass.valueOf = function (type) {
      return (type === 'object') ? klass : constructor.valueOf();
    };
    extend.call(klass, _static);
    // class initialization
    if (typeof klass.init === 'function') klass.init();
    return klass;
  };

  Base.prototype = {
    extend: function (source, value) {
      if (arguments.length > 1) { // extending with a name/value pair
        var ancestor = this[source];
        if (ancestor && (typeof value === 'function') && // overriding a method?
        // the valueOf() comparison is to avoid circular references
        (!ancestor.valueOf || ancestor.valueOf() !== value.valueOf()) && /\bbase\b/.test(value)) {
          // get the underlying method
          var method = value.valueOf();
          // override
          value = function () {
            var previous = this.base || Base.prototype.base;
            this.base = ancestor;
            var returnValue = method.apply(this, arguments);
            this.base = previous;
            return returnValue;
          };
          // point to the underlying method
          value.valueOf = function (type) {
            return (type === 'object') ? value : method;
          };
          value.toString = Base.toString;
        }
        this[source] = value;
      } else if (source) { // extending with an object literal
        var extend = Base.prototype.extend;
        // if this object has a customized extend method then use it
        if (!Base._prototyping && typeof this !== 'function') {
          extend = this.extend || extend;
        }
        var proto = {
          toSource: null
        };
        // do the "toString" and other methods manually
        var hidden = ['constructor', 'toString', 'valueOf'];
        // if we are prototyping then include the constructor
        for (var i = Base._prototyping ? 0 : 1; i < hidden.length; i++) {
          var h = hidden[i];
          if (source[h] !== proto[h])
            extend.call(this, h, source[h]);
        }
        // copy each of the source object's properties to this object
        for (var key in source) {
          if (!proto[key]) extend.call(this, key, source[key]);
        }
      }
      return this;
    }
  };

  // initialize
  Base = Base.extend({
    constructor: function () {
      this.extend(arguments[0]);
    }
  }, {
    ancestor: Object,
    version: '1.1',
    forEach: function (object, block, context) {
      for (var key in object) {
        if (this.prototype[key] === undefined) {
          block.call(context, object[key], key, object);
        }
      }
    },
    implement: function () {
      for (var i = 0; i < arguments.length; i++) {
        if (typeof arguments[i] === 'function') {
          // if it's a function, call it
          arguments[i](this.prototype);
        } else {
          // add the interface using the extend method
          this.prototype.extend(arguments[i]);
        }
      }
      return this;
    },
    toString: function () {
      return String(this.valueOf());
    }
  });

  // Return Base implementation
  return Base;
});