ogen

ogen

An observable Async/Await. An example for "Learn JavaScript with Eric Elliott"

Write asynchronous code that looks synchronous:

const myFunc = function* (param1, param2, param3) {
  const result = yield fetchSomething(); // returns promise

  // waits for promise and uses promise result
  yield result + ' 2';
  yield param1;
  yield param2;
  yield param3;
}

Pass it into ogen() and get back an observable that you can subscribe to:

const onNext = val => console.log(val);
const onError = err => console.log(err);
const onComplete = () => console.log('done.');

const asyncFunc = ogen(myFunc);

// Call the async function and pass params.
asyncFunc('a param', 'another param', 'more params!')
  .subscribe(onNext, onError, onComplete);
// future value
// future value 2
// a param
// another param
// more params!
// done.

Platform Notes

Obviously, this relies on generators. Works OK with Babel, Node v4+. Does not work in any IE without polyfills.

Should work in most other modern browsers.

Written for Learn JavaScript with Eric Elliott

An online course series for application developers. Ready to jump in? Learn more.