Javascript设计模式-发布/订阅模式最小化的示例

Javascript设计模式-发布/订阅模式最小化的示例

示例代码

/*经典的发布/订阅模式*/
var pubs = {};
(function(p){
var events = {},
subId = -1;

var subscribe = p.subscribe = function(name, callback, one){
var list = events[name] || (events[name] = []),
token = (++subId).toString();

list.push({
'token' : token,
'callback' : callback
});

return token;
}

var publish = p.publish = function(name, data){
var list = events[name], func;
if(list){
// Copy callback lists to prevent modification
list = list.slice()

// Execute event callbacks
while((func = list.shift()) && func.callback){
func.callback(name, data);
}
}
}

// Remove event. If `callback` is undefined, remove all callbacks for the
// event. If `event` and `callback` are both undefined, remove all callbacks
// for all events
var unsubscribe = p.unsubscribe = function(name, callback){
if (!(name || callback)) {
events = {};
return p;
}

var list = events[name];

if(list){
if(callback){
for (var i = list.length - 1; i >= 0; i--) {
if (list[i] === callback) {
list.splice(i, 1);
}
}
}else{
delete events[name];
}
}
}
})(pubs);

var messageLogger = function(name, data){
console.log(new Date().getTime() + "--Loggin : " + name + ":" + data )
};

var subcription = pubs.subscribe('inbox/newMessage', messageLogger);

pubs.publish('inbox/newMessage', 'Hello World');
pubs.publish('inbox/newMessage', 'Hello, are you still there?');
pubs.unsubscribe('inbox/newMessage');