中介者模式的作用就是解除对象与对象之间的紧耦合关系
中介者模式
例子一 泡泡堂游戏
function Player(name){
this.name = name;
this.enemy = null;
}
Player.prototype.win = function(){
console.log(this.name + ' won ');
}
Player.prototype.lose = function(){
console.log(this.name + ' lose ');
}
Player.prototype.die = function(){
this.lose();
this.enemy.win();
}
var play1 = new Player('皮蛋');
var play2 = new Player('盐蛋');
play1.enemy = play2;
play1.die();// 玩家一被炸死的时候，调用这一句就ok了
下面为游戏增加队伍
function Player(name,teamColor){
this.parteners = [];
this.enemies = [];
this.state = 'live';
this.name = name;
this.teamColor = teamColor;
}
Player.prototype.win = function(){
console.log(this.name + ' won ');
}
Player.prototype.lose = function(){
console.log(this.name + ' lose ');
}
Player.prototype.die = function(){
var all_dead = true;
this.state = 'dead';
for(var i=0,partener;partener = this.parteners[i++];){
if(partener.state !== 'dead'){
all_dead = false;
break;
}
}
if(all_dead === true){
this.lose();
for(var i = 0,partener;partener = this.parteners[i++];){
partener.lose();
}
for(var i = 0,enemy; enemy = this.enemies[i++];){
enemy.win();
}
}
}
var playerFactory = function(name.teamColor){
var newPlayer = new Player(name,teamColor);
for(var i = 0,player; player = players[i++];){
if(player.teamColor === newPlayer.teamColor){
player.parteners.push(newPlayer);
newPlayer.parteners.push(player);
}else{
player.enemies.push(newPlayer);
newPlayer.enemies.push(player);
}
}
}
在上面的代码中，每个玩家和其他玩家都是紧耦合在一起的，每个玩家的状态发生变化，都要通知其他的对象。
下面使用中介者模式改造上面的代码
function Player(name.teamColor){
this.name = name;//角色名称
this.teamColor = teamColor; // 队伍颜色
this.state = 'alive'; // 玩家生存状态
};
Player.prototype.win = function(){
console.log(this.name + ' won ');
};
Player.prototype.lose = function(){
console.log(this.name + ' lost ');
};
// 玩家死亡
Player.prototype.die = function(){
this.state = 'dead';
playerDirector.ReceiveMessage('playerDead',this); // 给中介者发送消息，玩家死亡
};
// 移除玩家
Player.prototype.remove = function(){
playerDirector.ReceiveMessage('removePlayer',this); // 给中介者发送消息，移除一个玩家
};
// 玩家换队
Player.prototype.changeTeam = function(color){
playerDirector.ReceiveMessage('changeTeam',this,color);// 给中介者发送消息，玩家换队
};
var placeFactory = function(name,teamColor){
var newPlayer = new Player(name,teamColor); // 创建一个新的玩家对象
playerDirector.ReceiveMessage('addPlayer'newPlayer);
return newPlayer;
}
