async.js

问题 I want to know how parallel execution works in async.js async = require('async') async.parallel([ function(callback){ for (var i = 0; i < 1000000000; i++) /* Do nothing */; console.log("function: 1") }, function(callback){ console.log("function: 2") } ]); In the above example, I expect obtain the output: function: 2 function: 1 but, the console throws the inverse, what is happening? thanks. 回答1: You get the answer you don't expect because async launches function: 1 first and it doesn't

问题 Been fighting with async module for half a day but can't get it to work properly when nesting few levels. So this works ok: var async = require('async') var myarr = ["Outer - A", "Outer - B"]; var myarr2 = ["Inner - A", "Inner - B"]; var innerComplete = true; async.eachSeries(myarr, function( item, outerCallback) { console.log('Processing item ' + item); async.series([ function(callback) { takeTime(2000, item, callback) }, function(callback) { takeTime(1000, item, callback) }, function

问题 I have this async function in a file called index.main.js which has a variable , 'targetFiles' which I would like to export to another file which is index.js. Problem is I can't find a way to export the value of this particular variable without getting "undefined" as a result. I have tried implementing promise, callback , export default function, and doing countless hours of research to no avail. //this code is in index.main.js var targetFiles = ""; async function listFilesInDepth() { const

问题 In my React application I have an array of parameters (some IDs, for example), which should be used as a parameters for an ajax call queue. The problem is that array might contain more than 1000 items and if I just recursively make the ajax call using the forEach loop, the browser page eventually stops responding before each of the requests are resolved. Is there a library, which could allow to send ajax requests, for example, maintaining 5 requests at a time asynchronously. This is the code

问题 Once fs.readFile loop through all files and get the matching data and push it to results, I want to call callback(results) so i can send response to client. I am getting an error with below code Error: Callback is already called HOw can i resolve this issue using async approach. app.js searchFileService.readFile(searchTxt, logFiles, function(lines, err) { console.log('Logs', lines); if (err) return res.send(); res.json(lines); }) readFile.js var searchStr; var results = []; function readFile

问题 Below is my code and I want to update my DB and thus have to use async but it is throwing following error-"TypeError: cb is not a function. at E:\smart-in-ffa\apis\node_modules\mongojs\lib\collection.js:106:7 at handleCallback (E:\smart-in-ffa\apis\node_modules\mongojs\node_modules\mongodb\lib\utils.js:96:56) at E:\smart-in-ffa\apis\node_modules\mongojs\node_modules\mongodb\lib\collection.js:1048:5 at E:\smart-in-ffa\apis\node_modules\mongojs\node_modules\mongodb\node_modules\mongodb-core\lib

问题 I am trying to loop though a collection and append an array of objects from a related collection. The result I am getting does not contain that array. Can anyone help me spot the issue? The model relationship is Page has many questions. Question Schema: var mongoose = require('mongoose'), Schema = mongoose.Schema; var questionSchema = new Schema({ _poll : { type: Schema.Types.ObjectId, ref: 'Poll' }, _page : { type: Schema.Types.ObjectId, ref: 'Page' }, type : { type : String, required: true

问题 I have two arrays. I would like to iterate the arrays using async.foreach. But when I do so, only the second array is getting executed.How to execute both. Below is my code: var _sizesArray1 = [_2000px, _1400px] var _sizesArray2 = [_800px, _400px, _200px, _100px] async.forEachOf(_sizesArray1, function(value, key, callback) { async.waterfall([ function download(next){ //code }, function convert(response, next) { //code }, function process(response, next) { gm(response).command('convert')

问题 I am using express-promise-router to achieve async/await in my query calls from node.js. Sometimes, when I need to fetch data for tables, I use async.parallel to get the data as well as the count as separate data and merge them. I am using callbacks here. How do I go ahead using async/await for these? router.post('/getDetail', (request, response, next) => { const id = request.body.id; const numPerPage = request.body.pSize; const pageNum = request.body.pIndex; let query = `select id,name,title

问题 I'm using Angular 7, now there is a method(Angular guard CanActivate) that contains some nested http call methods, i need to return data after all nested http call finished. As below code shows, only after getCurrentUser() finished, then return result in canActivate() , while now, it always return false because getCurrentUser() haven't finished. export class AuthGuard implements CanActivate{ constructor(private commonService: CommonService) { } async canActivate(next: ActivatedRouteSnapshot,