jquery源码01---(2880 , 3042) Callbacks : 回调对象 : 对函数的统一管理

// optionsCache : { 'once memory' : { once : true , memory : true } }
var optionsCache = {};

// once memory，options.match( core_rnotwhite )=[once, memory]，function( _, flag )={once:true,memory:true}
function createOptions( options ) {
var object = optionsCache[ options ] = {};//中括号就是json的点，没有点了。
jQuery.each( options.match( core_rnotwhite ) || [], function( _, flag ) {
object[ flag ] = true;
});
return object;
}

/*
var cb = $.Callbacks();
function aaa(){
alert(1);
}
cb.add(aaa);
(function(){
function bbb(){
alert(2);
}
cb.add(bbb);
})();
cb.fire();//1  2
*/
jQuery.Callbacks = function( options ) {//类的静态方法
//options 可选： once memory unique stopOnFalse
//方法：add remove has empty disable disabled lock locked fireWith fire fired
//什么都不写走jQuery.extend( {}, options )，返回空{},不这样写，如果options===undefined，后面还要做兼容。
options = typeof options === "string" ?
( optionsCache[ options ] || createOptions( options ) ) :
jQuery.extend( {}, options );//options={once:true,memory:true}

var
memory,
fired,
firing,
firingStart,
firingLength,
firingIndex,
// 添加的所有方法
list = [],
stack = !options.once && [],
fire = function( data ) {
memory = options.memory && data;//有memory返回true
fired = true;//触发开始
firingIndex = firingStart || 0;
firingStart = 0;
firingLength = list.length;
firing = true;
for ( ; list && firingIndex < firingLength; firingIndex++ ) {
if ( list[ firingIndex ].apply( data[ 0 ], data[ 1 ] ) === false && options.stopOnFalse ) {// 函数返回false,有stopOnFalse属性就不向下执行
memory = false; //memory也要置为false
break;
}
}
firing = false;//触发结束
if ( list ) {
if ( stack ) {
if ( stack.length ) {
fire( stack.shift() );
}
} else if ( memory ) {
list = [];
} else {
self.disable();
}
}
},
self = {//对外部接口
add: function() {
if ( list ) {//list一上来是空数组，会返回真，
var start = list.length;
(function add( args ) {//args是形参
jQuery.each( args, function( _, arg ) {//遍历传进来的多个方法名，
var type = jQuery.type( arg );
if ( type === "function" ) {
if ( !options.unique || !self.has( arg ) ) {//不是unioqye，或者是unipue但是没有
list.push( arg );
}
} else if ( arg && arg.length && type !== "string" ) {//数组，嵌套
add( arg );
}
});
})( arguments );//arguments是实参，方法名aaa,
if ( firing ) {
firingLength = list.length;
} else if ( memory ) {//第一次没有赋值是undefined，
firingStart = start;
fire( memory );
}
}
return this;
},
remove: function() {
if ( list ) {
jQuery.each( arguments, function( _, arg ) {//可以删除多个
var index;
while( ( index = jQuery.inArray( arg, list, index ) ) > -1 ) {
list.splice( index, 1 );//删除
if ( firing ) {
if ( index <= firingLength ) {
firingLength--;
}
if ( index <= firingIndex ) {
firingIndex--;
}
}
}
});
}
return this;
},
has: function( fn ) {
return fn ? jQuery.inArray( fn, list ) > -1 : !!( list && list.length );
},
empty: function() {
list = [];
firingLength = 0;
return this;
},
disable: function() {
list = stack = memory = undefined;
return this;
},
disabled: function() {
return !list;
},
lock: function() {
stack = undefined;
if ( !memory ) {
self.disable();
}
return this;
},
locked: function() {
return !stack;
},
fireWith: function( context, args ) {
if ( list && ( !fired || stack ) ) {
args = args || [];
args = [ context, args.slice ? args.slice() : args ];
if ( firing ) {
stack.push( args );
} else {
fire( args );
}
}
return this;
},
fire: function() {
self.fireWith( this, arguments );//cb.fire('hello');
return this;
},
fired: function() {
return !!fired;
}
};

return self;
};