asynchronous

Firebase, retrieving data asynchronously

由 混江龙づ霸主 提交于 2021-01-28 19:29:37
问题 I wrote a promise in javascript to delay an animation until some data is retrieved from my firebase database. The problem is that for some reason the promise isn't working, and the code isn't running asynchronously. Am i not using this promise properly, or is there another issue? var name = document.querySelector('.name') new Promise (function() { firebase.database().ref('users/' + userId ).on('value', function(snap) { console.log('first'); name.innerText = snap.child('name').val(); }); })

Angular 5 - Asynchronous Service Calls in two different components (First Method Not waiting for DB response)

由 ↘锁芯ラ 提交于 2021-01-28 18:50:07
问题 I have to perform two different DB transactions on a single (click) event. First Call : Save Data to DB. Second Call : Get the first call's saved data from DB These calls are separated in two different components and deal with one common DB Table. My approach is below : First Component TS : ngOnDestroy(){ this.saveData(); } Second Component TS : ngOnInit(){ this.getSavedData(); } Service call for First Method to Execute : saveData(obj) { return this.http.post(environment.appUrl + 'saveDataApi

Why there exist error Uncaught ReferenceError: $ is not defined if add async?

由 十年热恋 提交于 2021-01-28 18:31:43
问题 My index like this : ... <html > <head> ... <script src="/scripts/myapp.min.js"></script> <script src="/scripts/myapp-themming.min.js"></script> </head> <body class="header-static"> <div class="page-container"> <!-- this is call header, navigaton, content, footer --> </div> <script type="text/javascript" src="https://code.jquery.com/jquery-3.2.1.min.js"></script> <script type="text/javascript" src="/Content/assets/script/jquery-ui.min.js"></script> ... <script type="text/javascript"> ... <

Is std::launch::async policy needed?

由 走远了吗. 提交于 2021-01-28 12:23:50
问题 What is the difference in the following: std::async(my_function); and std::async(std::launch::async, my_function); What is the difference in using the pilicy std::launch::async in this case?? Does the first option not launch the function asynchronously anyway?? 回答1: The first one is equivalent to passing launch::async | launch::deferred , in which case it is up to the implementation whether it is launched asynchronously or merely deferred (called when a non-timed waiting function like get()

Async task could not keep up with for loop (firebase)

由 大憨熊 提交于 2021-01-28 12:13:14
问题 for (Uri mUri : mSelected) { imagesRef = storageRef.child(postid + mUri.getLastPathSegment()); imagesRef.putFile(mUri).addOnSuccessListener(task4 -> db.collection("posts").document(postid).update("photo_id", FieldValue.arrayUnion(imagesRef.getDownloadUrl()))); } So, now i am working with firestore and firebase storage. I uploaded (multiple) images to the storage, and when it is uploaded, i get the download url and wants to add it into my firestore. So, the problem is, only the last image is

Nodejs async function prototype chain error

由 此生再无相见时 提交于 2021-01-28 11:36:35
问题 why this code compiles var Person = function() { console.log("CALLED PERSON")}; Person.prototype.saySomething = function() { console.log("saySomething PERSON")}; var ape = new Person(); ape.saySomething(); and this code throws error Cannot set property 'saySomething' of undefined var Person = async function() { console.log("CALLED PERSON")}; Person.prototype.saySomething = function() { console.log("saySomething PERSON")}; var ape = new Person(); ape.saySomething(); 回答1: When you use async

C# Ping is not fast enough

由 时光毁灭记忆、已成空白 提交于 2021-01-28 10:56:29
问题 I am trying to make a scan wether the pc is online or offline. But my current code is way to slow to scan with a good performance as if an computer is offline there is a delay of 3 to 5 seconds. I even added the timeout parameter set as 500 but it still takes more than 3 seconds if a computer is offline. public bool PingComputer(string computername) { bool check = false; Ping ping = new Ping(); try { PingReply reply = ping.Send(computername, 500); check = reply.Status == IPStatus.Success; }

Boost asio async_read_until followed by async_read

由 允我心安 提交于 2021-01-28 10:34:21
问题 I used the async tcp server example from boost which is near to what my application is doing. The code example below is a fully working example. At first I start an async read operation until the delimiter char. In this case it is the http header complete sequence. The request contains some payload which is "hello world" (11 bytes). For a simplified example I use lambda handlers here. The first handler is called wit a length of 148 which is the header including four bytes for the delimiter

Boost asio async_read_until followed by async_read

由 核能气质少年 提交于 2021-01-28 10:31:56
问题 I used the async tcp server example from boost which is near to what my application is doing. The code example below is a fully working example. At first I start an async read operation until the delimiter char. In this case it is the http header complete sequence. The request contains some payload which is "hello world" (11 bytes). For a simplified example I use lambda handlers here. The first handler is called wit a length of 148 which is the header including four bytes for the delimiter

Execute .Then() promise NodeJS

由 你。 提交于 2021-01-28 09:41:09
问题 I am trying to figure out how to call a Promise using ".then" so I can continue performing other functions on the return Promise output. I have confirmed the function being used works as expected, but after watching videos and other SO examples am still having a hard time getting this working. See below snippet: const fs = require('fs'); const JSZip = require('jszip'); const directoryFile = fs.readdirSync('./zipped'); //console.log(directoryFile); var zip = new JSZip(); var dir = ('./zipped/'
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