如何在Angular中排队异步/同步功能？

Question

I need to execute several functions in a queue, but the functions may be sync, async, or even mixed (both) type, such as:

option = 1; // variable

do1() { // sync
    console.log(`hello, world`);
}

do2() { // async
    this.someService(`example.come`).subscribe( x => {
        option = 2;
        console.log(x);
    }, err => {
        option = 3;
        console.error(err);
    }
}

do3() { // mixed type, sync and async
    if (option === 4) {
        console.log(`happy day`);
    } else {
        option = 6;
        do2(); // <-- async func
    }
}

I hope I can write a very clean code as such:

waitUntilFinish do1();
waitUntilFinish do3();
waitUntilFinish do2();

Is it possible?

Answer 1

function f1() {
return new Promise((resolve, reject) => {
    console.log('f1');
    resolve();
});
}

 function f2() {
     console.log('f2');
  }

f1().then(res => f2());

WITH ASYNC AWAIT

If f1 is asynchronous and return a Promise, use async/await:

 async FUNC() {
   await f1();
   f2();
}