q

What is the difference between: new Promise(function(res, rej) { res("aaa"); }) .then(function(result) { return "bbb"; }) .then(function(result) { console.log(result); }); and this: new Promise(function(res, rej) { res("aaa"); }) .then(function(result) { return Promise.resolve("bbb"); }) .then(function(result) { console.log(result); }); I'm asking as I'm getting different behaviour Using Angular and $http service with chaining .then(). A bit too much code hence first the example above. Hrishi The rule is, if the function that is in the then handler returns a value, the promise resolves/rejects

This question already has an answer here: setTimeout and “this” in JavaScript 5 answers I have a javascript class, and each method returns a Q promise. I want to know why this is undefined in method2 and method3 . Is there a more correct way to write this code? function MyClass(opts){ this.options = opts; return this.method1() .then(this.method2) .then(this.method3); } MyClass.prototype.method1 = function(){ // ...q stuff... console.log(this.options); // logs "opts" object return deferred.promise; }; MyClass.prototype.method2 = function(method1resolve){ // ...q stuff... console.log(this); //

This question already has an answer here: setting a variable to get return from call back function using promise 2 answers How to return value from an asynchronous callback function? [duplicate] 3 answers I have a javascript function where I want to return the value that I get after the return method. Easier to see than explain function getValue(file){ var val; lookupValue(file).then(function(res){ val = res.val; } return val; } What is the best way to do this with a promise. As I understand it, the return val will return before the lookupValue has done it's then, but the I can't return res

What would be the idiomatic way to do something like a while loop with promises. So: do something if the condition still stands do it again repeat then do something else. dosomething.then(possilblydomoresomethings).then(finish) I've done it this way I was wondering if there were any better/more idomatic ways? var q = require('q'); var index = 1; var useless = function(){ var currentIndex = index; console.log(currentIndex) var deferred = q.defer(); setTimeout(function(){ if(currentIndex > 10) deferred.resolve(false); else deferred.resolve(true); },500); return deferred.promise; } var control =

I have implemented the $q.all in angularjs, but I can not make the code work. Here is my code : UploadService.uploadQuestion = function(questions){ var promises = []; for(var i = 0 ; i < questions.length ; i++){ var deffered = $q.defer(); var question = questions[i]; $http({ url : 'upload/question', method: 'POST', data : question }). success(function(data){ deffered.resolve(data); }). error(function(error){ deffered.reject(); }); promises.push(deffered.promise); } return $q.all(promises); } And here is my controller which call the services: uploadService.uploadQuestion(questions).then