javascript - JS : access from NEW inner object, 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能以及如何实现:

让我们假设一个如下示例:

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".

我怎样才能实现这个目标？如何使 ObjectB methodX() 调用其“容器/父级”(不是真正的父级，因为这不是继承)ObjectA 已经实例化 method2()？

我的想法是将对象 A 作为参数传递给对象 B，即“this”，例如:

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

这样，我将在 ObjectB 中拥有“完整的 objectA”来访问。已经实例化并且功能齐全。但这在我心中造成了一个深渊: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 A 再次访问 B，因此永远不会结束循环。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".