future

How to properly wait until future is complete in dart

由 时光毁灭记忆、已成空白 提交于 2019-11-27 08:34:42
问题 There is a slight bug in my app made with Flutter, that when the user has signed in, it fetches the user information from my database but not fast enough and causes a visual error on my front end of the app. The app has layouts that use the user information (name, location, and image) and it is not being loaded quick enough. I was wondering if there is a way to wait for my future to complete and once it is done, it can navigate the user to the front end with no problem. 回答1: You Should fetch

Await future for a specific time

由 断了今生、忘了曾经 提交于 2019-11-27 07:47:39
问题 How would you wait for future response for a specific amount of time? Say, we make a http post request and await for its response before we close the http request, but, we wait for only 3 secs, else we close the request. How would you achieve that? Something like Future makePostReq() async{ .... await http response for 3 secs .... if(response) { ... Do something with it } Http.close } 回答1: You can use Future.any constructor to make a race condition final result = await Future.any([ Future

Shiny promises future is not working on eventReactive

由 北城以北 提交于 2019-11-27 07:28:57
问题 I have an inputButton than when you click it, 2 querys to mysql database are done. One is a heavy one (more than 10 secs) and the other is light (less than 0.01sec to get data). As I want to show the result of this querys on shiny app, I have intendeed to use Promises and Future packages for asyncronous loading. In the example that I show you of my code, I have simulated the SQL querys with the function heavyFunction , which is intended to simulate the heavy query and the ligth one time loads

Future[Option] in Scala for-comprehensions

由 China☆狼群 提交于 2019-11-27 05:19:33
问题 I have two functions which return Futures. I'm trying to feed a modified result from first function into the other using a for-yield comprehension. This approach works: val schoolFuture = for { ud <- userStore.getUserDetails(user.userId) sid = ud.right.toOption.flatMap(_.schoolId) s <- schoolStore.getSchool(sid.get) if sid.isDefined } yield s However I'm not happy with having the "if" in there, it seems that I should be able to use a map instead. But when I try with a map: val schoolFuture:

How do I make a function involving futures tail recursive?

由 雨燕双飞 提交于 2019-11-27 05:15:39
In my Scala app, I have a function that calls a function which returns a result of type Future[T]. I need to pass the mapped result in my recursive function call. I want this to be tail recursive, but the map (or flatMap) is breaking the ability to do that. I get an error "Recursive call not in tail position." Below is a simple example of this scenario. How can this be modified so that the call will be tail recursive (without subverting the benefits of Futures with an Await.result())? import scala.annotation.tailrec import scala.concurrent.{Await, Future} import scala.concurrent.duration._

How to compose Observables to avoid the given nested and dependent callbacks?

由 流过昼夜 提交于 2019-11-27 04:16:54
问题 In this blog, he gives this (copy/pasted the following code) example for the callback hell. However, there is no mention of how the issue can be eliminated by using Reactive Extensions. So here F3 depends upon F1 completion and F4 and F5 depend upon F2 completion. Wondering what would be the functional equivalent in Rx. How to represent in Rx that F1, F2, F3, F4 and F5 should all be pulled asynchronously? NOTE: I am currently trying to wrap my head around Rx so I didn't try solving this

Why should I use std::async?

由 情到浓时终转凉″ 提交于 2019-11-27 04:12:28
问题 I'm trying to explore all the options of the new C++11 standard in depth, while using std::async and reading its definition, I noticed 2 things, at least under linux with gcc 4.8.1 : it's called async , but it got a really "sequential behaviour", basically in the row where you call the future associated with your async function foo , the program blocks until the execution of foo it's completed. it depends on the exact same external library as others, and better, non-blocking solutions, which

Disable future dates in jQuery UI Datepicker

由 徘徊边缘 提交于 2019-11-27 04:02:35
问题 Is it possible to disable future date from today? Let say today is 23/10/2010, so 24/10/2010 onwards are disabled. Sorry I am very new in jQuery and JavaScript. 回答1: Yes, indeed. The datepicker has the maxdate property that you can set when you initialize it. Here's the codez $("#datepicker").datepicker({ maxDate: new Date, minDate: new Date(2007, 6, 12) }); 回答2: $(function() { $("#datepicker").datepicker({ maxDate: '0'}); }); 回答3: Try This: $('#datepicker').datepicker({ endDate: new Date() }

How to use invokeAll() to let all thread pool do their task?

由 拥有回忆 提交于 2019-11-27 03:51:36
ExecutorService pool=Executors.newFixedThreadPool(7); List<Future<Hotel>> future=new ArrayList<Future<Hotel>>(); List<Callable<Hotel>> callList = new ArrayList<Callable<Hotel>>(); for(int i=0;i<=diff;i++){ String str="2013-"+(liDates.get(i).get(Calendar.MONTH)+1)+"-"+liDates.get(i).get(Calendar.DATE); callList.add(new HotelCheapestFare(str)); } future=pool.invokeAll(callList); for(int i=0;i<=future.size();i++){ System.out.println("name is:"+future.get(i).get().getName()); } Now I want pool to invokeAll all the task before getting to the for loop but when I run this program for loop gets

Transform Java Future into a CompletableFuture

由 本小妞迷上赌 提交于 2019-11-27 03:46:56
Java 8 introduces CompletableFuture , a new implementation of Future that is composable (includes a bunch of thenXxx methods). I'd like to use this exclusively, but many of the libraries I want to use return only non-composable Future instances. Is there a way to wrap up a returned Future instances inside of a CompleteableFuture so that I can compose it? nosid There is a way, but you won't like it. The following method transforms a Future<T> into a CompletableFuture<T> : public static <T> CompletableFuture<T> makeCompletableFuture(Future<T> future) { return CompletableFuture.supplyAsync(() ->
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