I like JavaScript promises. But I'm not too crazy about the ES6 way
(see MSDN) where
you get the resolve and reject as parameter of a function:
function doSomethingAsync() {
return new Promise(function(resolve, reject) {
callAsncCode(xyz, function(result) {
if(<result is ok>) {
resolve(someData);
}
else {
reject();
}
});
});
}
I would rather have something like this:
function doSomethingAsync() {
var promise = <gimme a promise>
callAsncCode(xyz, function(result) {
if(<result is ok>) {
promise.resolve(someData);
}
else {
promise.reject();
}
});
return promise;
}
To get this I always have this small ES6 class in my tool belt:
class SimplePromise {
constructor() {
const self = this;
this._promise = new Promise(function(resolve, reject) {
self._resolve = resolve;
self._reject = reject;
});
}
resolve(data) {
this._resolve(data);
}
reject(data) {
this._reject(data);
}
promise() {
return this._promise;
}
}
Now my code looks like this:
function doSomethingAsync() {
var promise = new SimplePromise();
callAsncCode(xyz, function(result) {
if(<result is ok>) {
promise.resolve(someData);
}
else {
promise.reject();
}
});
return promise.promise();
}
Not everyone may like it. I do.