What is the difference between .resolve() and .promise()?

Both resolve() and promise() are methods on the jQuery Deferred object. First a snippet from the jQuery documentation about Deferred: One model for understanding Deferred is to think of it as a chain-aware function wrapper. The deferred.then(), deferred.done(), and deferred.fail() methods specify the functions to be called and the deferred.resolve(args) or deferred.reject(args) methods “call” the … Read more

what is the difference between thunk, futures, and promises?

An example of each, using javascript since everybody can read it. Please don’t use this code in production, use a real library, there are plenty of good ones. var a, b, c, async_obj; // assume exist // CommonJS – for reference purposes try { async_obj.asyncMethod(a, b, c, function (error1, result1) { if (error1) { console.error(error1); … Read more

Wait until scope variable is loaded before using it in the view in angular.js

You ask: How can I wait for allPermissions to be loaded before the view renders? To prevent the entire view from rendering, you must use resolve. You don’t have to use the promise library though, since $http returns a promise: var app = angular.module(‘app’); app.config(function ($routeProvider) { $routeProvider .when(“https://stackoverflow.com/”, { templateUrl : ‘template.html’, controller : … Read more

Using promises with streams in node.js

In this line stream.on(“end”, resolve(stream.dests[0].path)); you are executing resolve immediately, and the result of calling resolve (which will be undefined, because that’s what resolve returns) is used as the argument to stream.on – not what you want at all, right. .on‘s second argument needs to be a function, rather than the result of calling a … Read more

Does this.setState return promise in react

You can promisify this.setState so that you can use the React API as a promise. This is how I got it to work: class LyricsGrid extends Component { setAsyncState = (newState) => new Promise((resolve) => this.setState(newState, resolve)); Later, I call this.setAsyncState using the standard Promise API: this.setAsyncState({ lyricsCorpus, matrix, count }) .then(foo1) .then(foo2) .catch(err => … Read more

Async function returning promise, instead of value [duplicate]

Async prefix is a kind of wrapper for Promises. async function latestTime() { const bl = await web3.eth.getBlock(‘latest’); console.log(bl.timestamp); // Returns a primitive console.log(typeof bl.timestamp.then == ‘function’); //Returns false – not a promise return bl.timestamp; } Is the same as function latestTime() { return new Promise(function(resolve,success){ const bl = web3.eth.getBlock(‘latest’); bl.then(function(result){ console.log(result.timestamp); // Returns a … Read more

How can I realize pattern promise/defered?

C# solves this with Tasks Tasks solve the same problem as promises do in JavaScript – and you can use them similarly. However normally, you shouldn’t. There are several differences: Tasks have cancellation built in. Tasks aren’t always started, and you can have tasks and start them later. Promises perform assimilation, you can’t have a … Read more