Multiple inheritance

[kalyn]

There's a class and a design function. It's trying to make a class that's kind of a descendant of both. In fact, the methods from the prototype of the design function are copied into a prototype class-out of the class.

Yeah, I know it's not a full inheritance, but it's enough to do that.

The problem is different. How do you get a typscrypt to take replicated methods?

class First {
  someMethod() {
    console.log('someMethod from First');
  }
}
function Second() {

console.log('Second');

}
Second.prototype.doSmth = function () {

console.log('doSmth from Second');

}
interface IBoth {

someMethod()

doSmth()

}
class Both extends First /* implements IBoth */ {

constructor() {

console.log('constructor of Both');

super();

Second.call(this);

}

}
for (let key in Second.prototype) {

Both.prototype[key] = Second.prototype[key];

}

In fact, we need to keep the methods visible to a level further.

class Final extends Both {

doIt() {

this.someMethod();

//this.doSmth(); // Надо заставить видеть метод тут

(this as any as IBoth).doSmth(); // Компилируется, но это ужас

}

}

If the methods are not visible from the very beginning Boththat's good.

That's what I've tried:

1. When trying to write

   class Both extends First implements IBoth {
   
   

   There's a mistake that I'm not working the interface.

2. Renamed Both Total _Both and use

   var Both = _Both as typeof _Both;
   
   

   Everything is as logical as it was, because there's no use here. First♪

3. Renamed Both Total _Both and use

   var Both = _Both as typeof IBoth;
   
   

   He says he can't find a name. IBoth♪

I've had a few more options, but they're completely insane.
What else can we do?

---

Let's try this: http://www.typescriptlang.org/Playground
http://www.typescriptlang.org/Playground#src=class%20First%20%7B%0D%0A%20%20someMethod()%20%7B%0D%0A%20%20%20%20console.log(

Start (right panel code) after adding the line:

(new Final).doIt();

Discharge of launch in the rewritten line this.doSmth();

constructor of Both

Second

someMethod from First

doSmth from Second

doSmth from Second

---

PS: https://stackoverflow.com/questions/34232656/imitate-multiple-inheritance

[Alberto]

We don't need an interface, we just need to announce a prototype field with the right type:

doSmth: () => void

She looks like a characteristic, not a method, but it's unscrupulous.

Full code:

class First {
  someMethod() {
    console.log('someMethod from First');
  }
}
function Second() {

console.log('Second');

}
Second.prototype.doSmth = function () {

console.log('doSmth from Second');

}
class Both extends First {

constructor() {

console.log('constructor of Both');

super();

Second.call(this);

}
doSmth: () => void

}
for (let key in Second.prototype) {

Both.prototype[key] = Second.prototype[key];

}
class Final extends Both {

doIt() {

this.someMethod();

this.doSmth();

//Both.prototype.doSmth(); // ok

//Final.prototype.doSmth(); // ok

}

}

PS: You should've googled not all the variants. typescript class prototype variable - I found the right way.