inheritance - Backbone View 继承-调用父级导致递归

Question

我有一个三个 Backbone View 类继承:

var preventRecursion = 0;

var parentView = Backbone.View.extend({

  initialize: function(){
    console.log('parentView');
  }
});

var nestedChildView = parentView.extend({

  initialize: function(){

    if (++preventRecursion == 5) {throw "Recursion"};

    console.log('nestedChildView');
    this.constructor.__super__.initialize.apply(this);          
  }
});

var nestedNestedChildView = nestedChildView.extend({

  initialize: function(){
    console.log('nestedNestedChildView');
    this.constructor.__super__.initialize.apply(this);          
  }
});

当我尝试创建nestedNestedChildView 时:

var t = new nestedNestedChildView();

我得到无限递归:
这里是 jsfiddle

Answer 1

正如 Model.extend 上的文档中所述,

Brief aside on super: JavaScript does not provide a simple way to call super — the function of the same name defined higher on the prototype chain. If you override a core function like set, or save, and you want to invoke the parent object's implementation, you'll have to explicitly call it, along these lines:

在您的类层次结构中， this.constructor总是等于 nestedNestedChildView 的构造函数, 这意味着 this.constructor.__super__.initialize将是 nestedChildView.initialize因此是一个循环。见 http://jsfiddle.net/X5yBb/进行测试。

您可以显式调用类 __super__ ( http://jsfiddle.net/X5yBb/1/ )

var nestedChildView = parentView.extend({
  initialize: function(){
    console.log('nestedChildView');
    nestedChildView.__super__.initialize.apply(this);          
  }
});

var nestedNestedChildView = nestedChildView.extend({
  initialize: function(){
    console.log('nestedNestedChildView');
    nestedNestedChildView.__super__.initialize.apply(this);          
  }
});

如果您愿意，也可以调用原型(prototype)链上的方法( http://jsfiddle.net/X5yBb/2/):

var nestedChildView = parentView.extend({
  initialize: function(){
    console.log('nestedChildView');
    parentView.prototype.initialize.apply(this);          
  }
});

var nestedNestedChildView = nestedChildView.extend({
  initialize: function(){
    console.log('nestedNestedChildView');
    nestedChildView.prototype.initialize.apply(this);          
  }
});

见 Accessing parent class in Backbone和 Super in Backbone有关该主题的更多信息。