自己动手实现 jQuery Callbacks 完整功能

  上次利用中午的时间实现了部分功能的jQuery Callbacks类 ， 具体可以参考上一篇 自己动手实现 jQuery Callbacks ,现在利用快下班的时间实现了其余的全部功能 ：callbacks.disable , callbacks.disabled,   callbacks.fired,callbacks.fireWith, callbacks.lock, callbacks.locked ,然后重构了下代码结构， 将实现放入了匿名函数内， 然后通过工厂方法 window.callbacks 返回实例，以免每次使用必须 new . 

       具体代码如下， 有兴趣和时间的可以对照jQuery版本的Callbacks对比下 ： 

 ( function ( window, undefined )
        {
            // Simulate jQuery.Callbacks object
            function Callbacks( options )
            {
                var ops = { once: false, memory: false, unique: false, stopOnFalse: false },
                    ar = [],
                    lastArgs = null,
                    firedTimes = 0,
                    _disabled = false,
                    _locked = false;

                if ( typeof options === 'string' && options.trim() !== '' )
                {
                    var opsArray = options.split( /\s+/ );
                    for ( var i = 0; i < options.length; i++ )
                    {
                        if ( opsArray[i] === 'once' )
                            ops.once = true;
                        else if ( opsArray[i] === 'memory' )
                            ops.memory = true;
                        else if ( opsArray[i] === 'unique' )
                            ops.unique = true;
                        else if ( opsArray[i] === 'stopOnFalse' )
                            ops.stopOnFalse = true;
                    }
                }

                function hasName( name )
                {
                    var h = false;

                    if ( typeof name === 'string'
                        && name !== null
                        && name.trim() !== ''
                        && ar.length > 0 )
                    {
                        for ( var i = 0; i < ar.length; i++ )
                        {
                            if ( ar[i].name === name )
                            {
                                h = true;
                                break;
                            }
                        }
                    }

                    return h;
                }

                // add a function
                this.add = function ( fn )
                {
                    if ( typeof fn === 'function' )
                    {
                        if ( ops.unique )
                        {
                            // check whether it had been added before
                            if ( fn.name !== '' && hasName( fn.name ) )
                            {
                                return this;
                            }
                        }

                        ar.push( fn );

                        if ( ops.memory )
                        {
                            // after added , call it immediately
                            fn.call( this, lastArgs );
                        }
                    }

                    return this;
                };

                // remove a function
                this.remove = function ( fn )
                {
                    if ( typeof ( fn ) === 'function'
                        && fn.name !== ''
                        && ar.length > 0 )
                    {
                        for ( var i = 0; i < ar.length; i++ )
                        {
                            if ( ar[i].name === fn.name )
                            {
                                ar.splice( i, 1 );
                            }
                        }
                    }

                    return this;
                };

                // remove all functions 
                this.empty = function ()
                {
                    ar.length = 0;
                    return this;
                };

                // check whether it includes a specific function
                this.has = function ( fn )
                {
                    var f = false;

                    if ( typeof ( fn ) === 'function'
                        && fn.name !== ''
                        && ar.length > 0 )
                    {
                        for ( var i = 0; i < ar.length; i++ )
                        {
                            if ( ar[i].name === fn.name )
                            {
                                f = true;
                                break;
                            }
                        }
                    }

                    return f;
                };

                this.disable = function ()
                {
                    _disabled = true;
                    return this;
                };

                this.disabled = function ()
                {
                    return _disabled;
                };

                this.fired = function ()
                {
                    return firedTimes > 0;
                };

                function _fire( context, args )
                {
                    if ( _disabled || ops.once && firedTimes > 0 || _locked )
                    {
                        return;
                    }

                    if ( ar.length > 0 )
                    {
                        var r;

                        for ( var i = 0; i < ar.length; i++ )
                        {
                            r = ar[i].call( context, args );

                            if ( ops.stopOnFalse && r === false )
                            {
                                break;
                            }
                        }
                    }

                    firedTimes++;

                    if ( ops.memory )
                    {
                        lastArgs = args;
                    }

                };

                this.fireWith = function ( context, args )
                {
                    context = context || this;
                    _fire( context, args );
                    return this;
                };

                this.fire = function ( args )
                {
                    _fire( this, args );
                    return this;
                };

                this.lock = function ()
                {
                    _locked = true;
                    return this;
                };

                this.locked = function ()
                {
                    return _locked;
                };

            };

            // exposed to global as a factory method
            window.callbacks = function ( options )
            {
                return new Callbacks( options );
            };

        } )( window );

为了测试fireWith ，增加了一个新的测试函数fn4 

       var fn1 = function ( v )
        {
            console.log( 'fn1 ' + ( v || '' ) );
        };

        var fn2 = function ( v )
        {
            console.log( 'fn2 ' + ( v || '' ) );
            return false;
        };

        function fn3( v )
        {
            console.log( 'fn3 ' + ( v || '' ) );
        };

        function fn4( args )
        {
            console.log( 'context is ' + this.toString() + ' argument is ' + args );
        };

1.测试fireWith 

var cb=callbacks() ; 

cb.add(fn4)

cb.fireWith() // context is [object Object] argument is undefined

cb.fireWith(1) // context is 1 argument is undefined

cb.fireWith(window,1) // context is [object Window] argument is 1

2. 测试 lock 

var cb=callbacks('memory');

cb.add(fn1) ; // fn1

cb.fire(1) // fn1 1

cb.add(fn2) // fn2 1

cb.lock() // 没有输出

cb.locked() // true

cb.fire(2) // 没有输出

3. 测试disable 

var cb=callbacks();

cb.add(fn1) ;

cb.fire(1) // fn1 1

cb.disable() ;

cb.disabled() // true

cb.fire(1) // 没有输出

通过以上重复造轮子， 对jQuery.Callbacks了解了也更多了一些 。接下来再造造jQuery其他方面的轮子，以学习和强化js 吧。。