Syntax for passing {} objects to typescript functions

Aquarius_Girl · 12-06-2020, 10:21 AM

https://rxjs-dev.firebaseapp.com/guide/observable

Code:

observable.subscribe({   
   next(x) { console.log('got value ' + x); },   
   error(err) { console.error('something wrong occurred: ' + err); },   
   complete() { console.log('done'); } });

As I can see they have passed functions to {} object and then passed this object as a parameter to function subscribe.

What is the function syntax for this kind of parameter accepting functions?
Does this actually mean that we are passing an object which has definitions of functions inside it as a function parameter?
Please point out the documentation.

SoftSprocket · 12-07-2020, 09:08 AM

I don't know typescript but I believe it accepts javascript constructs as well as its typed constructs? That's certainly acceptable javascript i.e.

Code:

$ node
 > var a = function (o) { o.x(); o.y(); }
undefined
> var b = { x() { console.log ("x"); }, y() { console.log ("y"); } };
undefined
> a(b);
x
y
undefined

Maybe an interface defined to take the three functions and a function defined to take the interface?

Code:

interface SubscribeArgs { 
   next: (string)=>void, 
   error: (string)=>void, 
   complete: ()=>void
} 

interface Observable {
    subscribe: (SubscribeArgs)=>void
}

I've no idea if that is correct but: https://www.tutorialspoint.com/types...interfaces.htm