Promises have three states Pending – this is how promises start. Fulfilled – this is what happens when you resolve a deferred, or when the return value from .then fulfills, and it generally analogous to a standard return value. Rejected – This is what happens when you reject a deferred, when you throw from a … Read more
What you need to use is $q.all which combines a number of promises into one which is only resolved when all the promises are resolved. In your case you could do something like: function outerFunction() { var defer = $q.defer(); var promises = []; function lastTask(){ writeSome(‘finish’).then( function(){ defer.resolve(); }); } angular.forEach( $scope.testArray, function(value){ promises.push(writeSome(value)); … Read more
You cannot make a synchronous result out of an asynchronous operation in Javascript. You just cannot do it. If any part of your operation is async, the entire result must be async and you must either use a callback, a promise or some other such mechanism to communicate when the operation is done and the … Read more
Promises for promises that are yet to be created …are easy to build by chaining a then invocation with the callback that creates the promise to a promise represents the availability to create it in the future. If you are making a promise for a promise, you should never use the deferred pattern. You should … Read more
This is not going to be a complete answer to your question, but hopefully this will help you and others when you try to read the documentation on the $q service. It took me a while to understand it. Let’s set aside AngularJS for a moment and just consider the Facebook API calls. Both the … Read more
These answers, including the selected answer, are good for introducing promises conceptually, but lacking in specifics of what exactly the differences are in the terminology that arises when using libraries implementing them (and there are important differences). Since it is still an evolving spec, the answer currently comes from attempting to survey both references (like … Read more
In each case, return the jqXHR object returned by $.ajax(). These objects are Promise-compatible so can be chained with .then()/.done()/.fail()/.always(). .then() is the one you want in this case, exactly as in the question. function first() { return $.ajax(…); } function second(data, textStatus, jqXHR) { return $.ajax(…); } function third(data, textStatus, jqXHR) { return $.ajax(…); … Read more
To me, this result doesn’t make sense. By attaching to this promise chain, each then is implying the intent that it will be dependant upon the successful resolution of d1 and a result being passed down the chain No. What you are describing is not a chain, but just attaching all the callbacks to d1. … Read more