微信小程序中实现一对多发消息详解及实例代码

notificationCenter:{},// 向通知中心注册一个监听者。
// name: 监听的通知名称
// observer: 监听者
// action: 监听者收通知时调用的方法名，
// func: 监听者收到通知时调用的函数，
// action func 2选1
register:function(name,observer,action,func){
if (!name || !observer) return;
if (!action && !func) return;

console.log("注册通知：",observer);

var center = this.notificationCenter;
var objects = center[name];
if (!objects){
objects = [];
}
this.remove(name,observer);
objects.push({
observer:observer,action:action,func:func
});
center[name] = objects;
},// 从通知中心移除一个监听者
remove:function(name,observer){
if (!name || !observer) return;

var center = this.notificationCenter;
var objects = center[name];
if (!objects){
return;
}

var idx;
var object;
for(idx = 0;idx<objects.length;idx++){
var obj = objects[idx];
if (obj.observer == observer){
object = obj;
break;
}
}
if (object){
objects.splice(idx,1);
}
center[name] = objects;
},// 通过通知中心发出通知
// name: 通知名称
// notification: 通知内容
post:function(name,notification){
if (!name) return;

console.log("准备发出通知：",notification);

var center = this.notificationCenter;
var objects = center[name];
if (!objects){
objects = [];
}
objects.forEach(function(object){
var observer = object.observer;
var action = object.action;
var func = object.func;

if (observer && action){
  func = observer[action];
}
func(notification);

});

console.log("完成向 ",objects.length," 个监听者发出通知：",name);
}
}

function center(){
return notificationCenter;
}

module.exports.center = center;