4.js模式-发布-订阅模式

1. 发布-订阅模式

var observe = (function(){

var events = {},

listen,

trigger,

remmove;

listen = function(key,fn){

if(!events[key]){

events[key] = [];

}

events[key].push(fn);

};

trigger = function(){

var key = Array.prototype.shift.call(arguments);

var fns = events[key];

if(!fns || fns.length === 0){

return false;

}

for(var i=0,fn;fn=fns[i++];){

fn.apply(this,arguments);

}

};

remove = function(key,fn){

var fns = events[key];

if(!fns){

return false;

}

if(!fn){

fns && (fns.length=0);

}else{

for(var l =fns.length -1;l>=0;l--){

var _fn = fns[l];

if(_fn===fn){

fns.splice(l,1);

}

}

}

};

return {

listen:listen,

trigger:trigger,

remove:remove

}

})();

• observe.listen('xx',function(price){

console.log(price);

});

observe.trigger('xx',2000);