Async/await example

by Nibin George

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-polyfill/6.7.4/polyfill.min.js"></script>

Babel + JSX

//omises were intoduces inorder to solve the callback hell issue.Later bservables were introduced which has 2 importanat advantages over promises whuch are working on stram of data and an amazing set of operations for async oerations.Annoying thing about promises or observables is that code is writtn in blocks which is basically solved in aysn await

//Asysnc Await

async function getPlayerAsync() {
    var response = await fetch('/sample');
    var players = await response.json();
    
    return players;
}

getPlayerAsync().then(players => console.log(players));

//Promise

delay().then(function(response) {
	alert('Promised!');
});

function delay() {
	return new Promise(function(resolve,reject) {
		setTimeout(function() {
			resolve('success');
			//reject('error');
		},2000);
	});
}

//Obsrvables
let playerUrl = 'https://example.com/players'
let requests$ = Rx.Observable.just(usersUrl)

let responses$ = requests$
  .flatMap(url => Rx.Observable.fromPromise(fetch(url)))
  .flatMap(r => Rx.Observable.fromPromise(r.json()))
  
responses$.subscribe(users => {
   console.log(users[0].login); // => result
})