Given a Ajax request in AngularJS $http.get(“/backend/”).success(callback); what is the most effective way to cancel that request if another request is launched (same backend, different parameters for instance). 8 Answers 8
I’m still struggling with promises, but making some progress thanks to the community here. I have a simple JS function which queries a Parse database. It’s supposed to return the array of results, but obviously due to the asynchronous nature of the query (hence the promises), the function returns before the results, leaving me with … Read more
I’ve been messing around with the fetch() api recently, and noticed something which was a bit quirky. let url = “http://jsonplaceholder.typicode.com/posts/6”; let iterator = fetch(url); iterator .then(response => { return { data: response.json(), status: response.status } }) .then(post => document.write(post.data)); ; post.data returns a Promise object. http://jsbin.com/wofulo/2/edit?js,output However if it is written as: let url … Read more
I have got a javascript code like this: function justTesting() { promise.then(function(output) { return output + 1; }); } var test = justTesting(); I have got always an undefined value for the var test. I think that it is because the promises are not resolved yet..there is a way to return a value from a … Read more
I have a pure JavaScript Promise (built-in implementation or poly-fill): var promise = new Promise(function (resolve, reject) { /* … */ }); From the specification, a Promise can be one of: ‘settled’ and ‘resolved’ ‘settled’ and ‘rejected’ ‘pending’ I have a use case where I wish to interrogate the Promise synchronously and determine: is the … Read more
Node.js from version 7 has async/await syntactic sugar for handling promises and now in my code the following warning comes up quite often: (node:11057) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): ReferenceError: Error: Can’t set headers after they are sent. (node:11057) DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not … Read more
My code: let AuthUser = data => { return google.login(data.username, data.password).then(token => { return token } ) } And when i try to run something like this: let userToken = AuthUser(data) console.log(userToken) I’m getting: Promise { <pending> } But why? My main goal is to get token from google.login(data.username, data.password) which returns a promise, into … Read more
Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. I want to use (native) promises in my frontend app to perform XHR request but without all the tomfoolery of a massive framework. I … Read more
I had a look at the bluebird promise FAQ, in which it mentions that .then(success, fail) is an antipattern. I don’t quite understand its explanation as for the try and catch. What’s wrong with the following? some_promise_call() .then(function(res) { logger.log(res) }, function(err) { logger.log(err) }) It seems that the example is suggesting the following to … Read more
I’ve just finished reading the Promises/A+ specification and stumbled upon the terms microtask and macrotask: see http://promisesaplus.com/#notes I’ve never heard of these terms before, and now I’m curious what the difference could be? I’ve already tried to find some information on the web, but all I’ve found is this post from the w3.org Archives (which … Read more
