在Node中递归地需要模块

Question

So, let's say I have two classes, each of which requires the other:

Department.js:

const Person = require("./Person");
class Department{
  constructor(id){
    this.personel = getPersonel(id).map(person => new Person(person));
  }
}

Person.js

const Department = require("./Department");
class Person {
  constructor(id){
    this.department = new Department(getDeptOfPerson(id));
  }
}
const person = new Person(1);
const coworkers = person.department.personel;

Now, this doesn't work, and I can kinda understand why. It says "Person" is not a constructor at Department.js. However, if I put both classes in the same file, it works just fine.

So; my question is, how do I work around this? I'd really rather not keep both of these classes in the same file -- is there a better way?

I'm running the latest version of Node.

Answer 1

You can separate initializing objects from fetching data:

// types/Department.js
class Department {
  constructor(id, personnel) {
    this.id = id;
    this.personnel = personnel;
  }
}

// types/Person.js
class Person {
  constructor(id, department) {
    this.id = id;
    this.department = department;
  }
}

// findDepartment.js
const Department = require('./types/Department');
const Person = require('./types/Person');

function findDepartment(id) {
  const personnel = getPersonnel(id).map(person => new Person(person));
  return new Department(id, personnel);
}

// findPerson.js
const Department = require('./types/Department');
const Person = require('./types/Person');

function findPerson(id) {
  const department = getDeptOfPerson(id);
  return new Person(id, department);
}

These can even go back on the types ( findDepartment.js → Department.js , Department.findDepartment = function (id) { … ) if you really want.