promise

问题 const returnPostData = async (req, res, initialPostsQueryArray) => { try{ const promises = initialPostsQueryArray.map( async (post) => { let voteCount = 0; let voted = false; let liked = false; let userHandle; let userImageUrl; let votingOptionsDictionary; let userVoteOption; voteCount = sumValues(post.voting_options); pool.query('SELECT userhandle, image_url FROM users WHERE id = $1 ', [post.user_id], (error, results) => { if (error) { console.log(error); return res.json({'Error': error

问题 const returnPostData = async (req, res, initialPostsQueryArray) => { try{ const promises = initialPostsQueryArray.map( async (post) => { let voteCount = 0; let voted = false; let liked = false; let userHandle; let userImageUrl; let votingOptionsDictionary; let userVoteOption; voteCount = sumValues(post.voting_options); pool.query('SELECT userhandle, image_url FROM users WHERE id = $1 ', [post.user_id], (error, results) => { if (error) { console.log(error); return res.json({'Error': error

问题 I'm working on IPC in NodeJS and want to be able to send a message to the parent process from the child and "wait" for the result. My idea was to keep track of all the send messages in a map that maps the unique message ID to a promise. Once the process.on('message`) has been called I lookup the promise by the ID I got back from the parent and want to resolve or reject the promise. I came up with this, but am stuck at the resolve/reject part: 'use strict' import RequestMessage from "..

问题 I'm working on IPC in NodeJS and want to be able to send a message to the parent process from the child and "wait" for the result. My idea was to keep track of all the send messages in a map that maps the unique message ID to a promise. Once the process.on('message`) has been called I lookup the promise by the ID I got back from the parent and want to resolve or reject the promise. I came up with this, but am stuck at the resolve/reject part: 'use strict' import RequestMessage from "..

问题 Problem Overview: I have a GreaseMonkey/TamperMonkey script in FireFox that sends several GM_xmlhttpRequest ( essentially similar to a xml http request, however this wrapper allows ease in cross-origin requests ) to URL's to retrieve simple JSON data. Some of the JSON data retrieved is super simple, like so, {id:123459876, code:"frog"} [{value:"water", contents:0}] This leads me to my outline of what code I've got down for my programming task so far, and, eventually shapes what I'll ask in

问题 Problem Overview: I have a GreaseMonkey/TamperMonkey script in FireFox that sends several GM_xmlhttpRequest ( essentially similar to a xml http request, however this wrapper allows ease in cross-origin requests ) to URL's to retrieve simple JSON data. Some of the JSON data retrieved is super simple, like so, {id:123459876, code:"frog"} [{value:"water", contents:0}] This leads me to my outline of what code I've got down for my programming task so far, and, eventually shapes what I'll ask in

问题 I would like to add some timeout between below get requests. I mean, flow should be looks like: timeout, https://example.com/example1, timeout, https://example.com/example2, timeout, https://example.com/example3, timeout etc. (or without first timeout, whatever). Below function is working properly: function promiseGetInformationFromMultipleUrls(parts) { return Promise.all(parts.map(part => { return request({ 'url': `https://example.com/${part}`, 'json': true }).then(partData => {console.log(

问题 How do you execute a function only after all the promises are resolved where you have to wait for async calls in loops within loops? The code is simplified to the minimum $scope.book = function(input) { //Get the cart items from DB ref.child('/cart/' + userId).once('value').then(function(cartSnap) { //Loop through the cart items cartSnap.forEach(function(cartItemSnap) { var itemId = cartItemSnap.key(); //Get the inventory items from DB that are in the cart ref.child('/inventory/' + itemId)

问题 I have the following piece of code that results in compile error in TypeScript: type Promisable = (() => Promise<string>) | (() => Promise<number>); const func = async (promisable: Promisable) => { await Promise.all([promisable()]); }; The error is as follows No overload matches this call. The last overload gave the following error. Argument of type '(Promise | Promise)[]' is not assignable to parameter of type 'Iterable>'. The types returned by 'Symbol.iterator.next(...)' are incompatible

问题 I have a method for validating a string, I want that method to return a Promise as the validations being ran may be asynchronous. The issue I am having however is one of performance, I want the promise to resolve in the same event loop when possible (eg: when there are no asynchronous validations to be done) but I want the interface to remain consistent (eg: to always return a Promise). The simplified code example below illustrates what I'm trying to do, but it incurs the aforementioned