Node v7.5.0 Released

Post by latch » Fri, Feb 03, 2017, 1:07 PM UTC

zachrose wrote: post #45

Bahamut wrote: post #36

Earlier quoted context omitted.

I highly recommend against using that library - it encourages a lot of callback hell we've found at my company, and it is much harder to create nice reusable functions with it vs. promises. bluebird is a wholly superior library for handling async flow.

So much of the promise-based code I see looks almost the same as it would with plain callbacks, just with the callbacks plopped into .then(). Am I missing something? How do promises make for more reusable functions?

Post by woudsma » Fri, Feb 03, 2017, 1:09 PM UTC

egeozcan wrote: post #49

zachrose wrote: post #45

Earlier quoted context omitted.

So much of the promise-based code I see looks almost the same as it would with plain callbacks, just with the callbacks plopped into .then(). Am I missing something? How do promises make for more reusable functions?

You can take the part before `.then()` and pass it around.

  const result = await db.get(doc)

  console.log('result:', result)

  db.get(doc, result => {
    console.log('result:', result)
  });

  db.get(doc)
    .then(result => 'result: ' + result)
    .then(::console.log)
    .catch(::console.error)

}

Post by thealfreds » Fri, Feb 03, 2017, 1:13 PM UTC

zachrose wrote: post #45

Bahamut wrote: post #36

Earlier quoted context omitted.

I highly recommend against using that library - it encourages a lot of callback hell we've found at my company, and it is much harder to create nice reusable functions with it vs. promises. bluebird is a wholly superior library for handling async flow.

So much of the promise-based code I see looks almost the same as it would with plain callbacks, just with the callbacks plopped into .then(). Am I missing something? How do promises make for more reusable functions?

    function someController(req, res) {
        UserService.getUser(req.session.user)
            .then(SomeService.getSomething)
            .then((val) => res.json(val))
            .catch(handleError);
    }

    function getSomething(user) {
        return SomeRepo.getSomething(user)
            .then(MapSomething)
            .catch(alternativeHigherLevelCatch);
    }

    function getSomething(user) {
        return new Promise((resolve, reject) => {
            database.getSomething(
                'defined parameters',
                user,
                resolve,
                reject
            )
        });
    }

Post by sotojuan » Fri, Feb 03, 2017, 1:31 PM UTC

nodesocket wrote: post #26

GeneralMaximus wrote: post #21

Earlier quoted context omitted.

You have a number of ways of keeping a handle on async code now. 1. Native ES6 promises will cover most of your basic needs. See https://developer.mozilla.org/en/docs/Web/JavaScript/Referen... . In fact, unless you have very specific needs not covered by native promises, you shouldn't drop a third party library into your project. 2. For more advanced operations on promises, use Bluebird. See http://bluebirdjs.com and…

Also highly recommend the npm async library[1] even though the hipster way is now native async/wait or promises. caolan/async has some amazing sugar on nearly every use-case the most common for me being async.auto(). [1] https://github.com/caolan/async

Post by fb03 » Fri, Feb 03, 2017, 1:35 PM UTC

tragic wrote: post #43

imrehg wrote: post #34

Earlier quoted context omitted.

"AWS Lambda supports the following runtime versions: Node.js – v4.3.2" http://docs.aws.amazon.com/lambda/latest/dg/current-supporte...

Better than the Python story, at least ...