JS：从新的内部对象访问，父容器创建者对象方法/变量

Question

大家下午好。

我需要知道这样的事情是否可行以及如何：

让我们假设如下示例：

function ObjectB(pFoo){
  //Some object vars/properties
  this.varX = '';
  
  //Some object methods
  this.methodX = function(){
    //...
    //HERE. is where I want to call the function/method from "my container/parent", which is an instanced ObjectA. How can I call for example, "method2()" from ObjectA?
    //...
  };
  this.methodY = function(){
    //...
    console.log(this.varX);
    //...
  };
  
  //Constructor time
  this.varX = pFoo;
}

function ObjectA(pA, pB){
  //Some object vars/properties
  this.var1 = '';
  this.var2 = '';
  this.innerObjB = null;
  
  //Some object methods
  this.method1 = function(){
    //...
    this.innerObjB.methodY(); //No problem at all: calls method from it's own inner "var/property" self object.
    //...
  };
  this.method2 = function(){
    //...
    this.var2 = 'trololo';
    //...
  };
  this.method3 = function(){
    //...
    this.innerObjB.methodX();
    //...
  };
  this.method4 = function(){
    //...
    console.log(this.var2);
    //...
  };
  
  //Constructor time
  this.var1 = pA;
  this.var2 = pB;
  this.innerObjB = new ObjectB("whatever");
}

//Runtime
var ObjA = new ObjectA("blah", "bleh");
ObjA.method1(); //prints "whatever".
ObjA.method4(); //prints "bleh".
ObjA.method3(); //calls innerObjB.methodX(), which SHOULD call ObjectA method2().
ObjA.method4(); //If previous thing were resolved, now this should print "trololo".

我怎样才能做到这一点？如何使 ObjectB 的 methodX() 调用它的“容器/父级”（不是真正的父级，因为这不是继承）ObjectA 已经实例化了 method2()？

我的想法是作为参数从对象 A 传递给对象 B，即“this”，例如：

this.innerObjB = new ObjectB("whatever", this);

这样，我将在 ObjectB 中访问“完整的 objectA”。已经实例化并且功能齐全。 但这在我的中间造成了一个深洞：这不是一种罕见的“递归”依赖吗？因为您可以再次从 B 访问 A，然后从该 A 访问 B 再一次，永远不要结束循环。所以这根本没有多大意义......

感谢您的宝贵时间。

亲切的问候，

马克。

Answer 1

ObjectB 需要被告知它的容器是什么。容器可以作为参数传递给构造函数。

function ObjectB(pFoo, container) {
  //Some object vars/properties
  this.varX = '';
  this.container = container;

  //Some object methods
  this.methodX = function() {
    this.container.method2();
  };
  this.methodY = function() {
    //...
    console.log(this.varX);
    //...
  };

  //Constructor time
  this.varX = pFoo;
}

function ObjectA(pA, pB) {
  //Some object vars/properties
  this.var1 = '';
  this.var2 = '';
  this.innerObjB = null;

  //Some object methods
  this.method1 = function() {
    //...
    this.innerObjB.methodY(); //No problem at all: calls method from it's own inner "var/property" self object.
    //...
  };
  this.method2 = function() {
    //...
    this.var2 = 'trololo';
    //...
  };
  this.method3 = function() {
    //...
    this.innerObjB.methodX();
    //...
  };
  this.method4 = function() {
    //...
    console.log(this.var2);
    //...
  };

  //Constructor time
  this.var1 = pA;
  this.var2 = pB;
  this.innerObjB = new ObjectB("whatever", this);
}

//Runtime
var ObjA = new ObjectA("blah", "bleh");
ObjA.method1(); //prints "whatever".
ObjA.method4(); //prints "bleh".
ObjA.method3(); //calls innerObjB.methodX(), which SHOULD call ObjectA method2().
ObjA.method4(); //If previous thing were resolved, now this should print "trololo".