Question

我有3个班级:

function A(data){
    this.data = data || [];
}    
A.prototype.remove = function(index){
    // remove index from this.data;
};
function B(data){
    this.data = data || [];
}  
B.prototype.add = function(x){
    this.data.push(x);
};
B.prototype.update = function(index, x){
    this.data[index] = x;
};
function C(data){  
    this.data = data || [];
}
C.prototype.add = function(x){
    this.data.push(x);
};
var a = new A(xx);
var b = new B(xx);
var c = new C(xx);

There relations are:
if I call a.remove(i) to remove an element, b will add it to its data.
if I call b.update(i, x), c will add x to its data.
How could I design this with smallest coupling?

ps: 这只是表明情况的一个实例,请不注意初始化等。

Answer 1

我最好利用事件进行松散的政变。作为基础,我建议使用。 (见背后。) 活动科的足迹非常小,为你们提供了大量的习俗活动支助。缩略语:

活动是一种可与任何物体混在一起的模块,使物体有能力约束和触发特定事件。

It could look like this:

function A(data){
    this.data = data || [];
}    
A.prototype.remove = function(index){
    // remove index from this.data;
    // dispatch A_Remove event
    this.trigger("A_Remove", this.data);
};
function B(data){
    this.data = data || [];
}  
B.prototype.add = function(x){
    this.data.push(x);
};
B.prototype.update = function(index, x){
    this.data[index] = x;
    this.trigger("B_Update", x);
};
function C(data){  
    this.data = data || [];
}
C.prototype.add = function(x){
    this.data.push(x);
};
var a = new A(xx);
var b = new B(xx);
var c = new C(xx);

// mixin event support to your objects
_.extend(a, Backbone.Events);
_.extend(b, Backbone.Events);
_.extend(c, Backbone.Events);

// event listener for A_Remove event
a.bind("A_Remove", function(data) {
    b.add(data);
});
// event listener for B_Update event
b.bind("B_Update", function(data) {
    c.add(data);
});

由于采取这种基于事件的做法,你的班子与他们一样松散,不需要A、B或C相互了解。与此同时,你具有最大的灵活性——在任何时候都可以增加更多的听众或活动类型。

我认为这是最佳解决办法。

Answer 2

我要补充A类和B类的反馈。

function A(data, callback) {
  this.data = data || [];
  this.callback = callback || function() {};
}

A.prototype.remove = function(index) {
  // remove index from this.data;
  this.callback(this.data[index]);
}
...
var b = new B(xx);
var a = new A(xx, function(e) {b.add(e);});

友情链接