解读sencha touch移动框架的核心架构(一)

Ext.apply(Ext, {

        /**
         * This method deprecated. Use {@link Ext#define Ext.define} instead.
         * @method
         * @param {Function} superclass
         * @param {Object} overrides
         * @return {Function} The subclass constructor from the `overrides` parameter, or a generated one if not provided.
         * @deprecated 2.0.0 Please use {@link Ext#define Ext.define} instead
         */
        extend: function() {
            // inline overrides
            var objectConstructor = objectPrototype.constructor,
                inlineOverrides = function(o) {
                for (var m in o) {
                    if (!o.hasOwnProperty(m)) {
                        continue;
                    }
                    this[m] = o[m];
                }
            };

            return function(subclass, superclass, overrides) {
                // First we check if the user passed in just the superClass with overrides
                if (Ext.isObject(superclass)) {
                    overrides = superclass;
                    superclass = subclass;
                    subclass = overrides.constructor !== objectConstructor ? overrides.constructor : function() {
                        superclass.apply(this, arguments);
                    };
                }

                //<debug>
                if (!superclass) {
                    Ext.Error.raise({
                        sourceClass: 'Ext',
                        sourceMethod: 'extend',
                        msg: 'Attempting to extend from a class which has not been loaded on the page.'
                    });
                }
                //</debug>

                // We create a new temporary class
                var F = function() {},
                    subclassProto, superclassProto = superclass.prototype;

                F.prototype = superclassProto;
                subclassProto = subclass.prototype = new F();
                subclassProto.constructor = subclass;
                subclass.superclass = superclassProto;

                if (superclassProto.constructor === objectConstructor) {
                    superclassProto.constructor = superclass;
                }

                subclass.override = function(overrides) {
                    Ext.override(subclass, overrides);
                };

                subclassProto.override = inlineOverrides;
                subclassProto.proto = subclassProto;

                subclass.override(overrides);
                subclass.extend = function(o) {
                    return Ext.extend(subclass, o);
                };

                return subclass;
            };
        }(),

        /**
         * Proxy to {@link Ext.Base#override}. Please refer {@link Ext.Base#override} for further details.
         *
         * @param {Object} cls The class to override
         * @param {Object} overrides The properties to add to `origClass`. This should be specified as an object literal
         * containing one or more properties.
         * @method override
         * @deprecated 2.0.0 Please use {@link Ext#define Ext.define} instead.
         */
        override: function(cls, overrides) {
            if (cls.$isClass) {
                return cls.override(overrides);
            }
            else {
                Ext.apply(cls.prototype, overrides);
            }
        }
    });

var F = function() {},
     F.prototype = superclassProto;
     subclassProto = subclass.prototype = new F();

var a = function(id){
    this.name = id;
}

a.prototype = {
    sayA : function(){
        alert(this.name)
    }
};

var b = Ext.extend(a, {
    constructor:function(name){
        this.name = name;
    },
    sayB : function(){
        this.constructor.superclass.constructor(111)
    }
});

c =  new b('Aaron')