例子的详细讲解
Filter Resolve
上面的的代码是怎么运行的呢
点击button的先执行 $.Deferred(),得到具有很多方法的defer
defer.resolve( 5 );
var doneList = jQuery.Callbacks( "once memory" ),
failList = jQuery.Callbacks( "once memory" ),
progressList = jQuery.Callbacks( "memory" ),
state = "pending";
lists = {
resolve: doneList,
reject: failList,
notify: progressList
}
for ( key in lists ) {
deferred[ key ] = lists[ key ].fire;
deferred[ key + "With" ] = lists[ key ].fireWith;
}
//根据上面的代码可得
//deferred[ 'resolve']=lists[ 'resolve'].fire;
//deferred[ 'resolveWidth']=lists[ 'resolve'].fireWith;
//deferred[ 'reject']=lists[ 'reject'].fire;
//deferred[ 'rejectWidth']=lists[ 'reject'].fireWith;
//deferred[ 'notify']=lists[ 'notify'].fire;
//deferred[ 'notifyWidth']=lists[ 'notify'].fireWith;
//因此resolve( 5 )执行了
fire: function() {
self.fireWith( this, arguments );
return this;
},
fireWith: function( context, args ) {
//stack=[];为true;firing 为false;flag={}
if ( stack ) {
if ( firing ) {
if ( !flags.once ) {
stack.push( [ context, args ] );
}
//memory =undefined
} else if ( !( flags.once && memory ) ) {
fire( context, args );
}
}
return this;
}
fire = function( context, args ) {
args = args || [];
//memory = [ context, args ];即为self,和5
memory = !flags.memory || [ context, args ];
fired = true;
firing = true;
firingIndex = firingStart || 0;
firingStart = 0;
firingLength = list.length;
for ( ; list && firingIndex < firingLength; firingIndex++ ) {
//函数执行后为false并且flags.stopOnFalse 为true时memory = true;
//注意这里执行了函数
if ( list[ firingIndex ].apply( context, args ) === false && flags.stopOnFalse ) {
memory = true; // Mark as halted
break;
}
}
firing = false;
if ( list ) {
if ( !flags.once ) {
if ( stack && stack.length ) {
memory = stack.shift();
self.fireWith( memory[ 0 ], memory[ 1 ] );
}
} else if ( memory === true ) {
self.disable();
} else {
//最终又把list函数组给赋值为空
list = [];
}
}
}