AngularJS $ q：如何在链中并行完成诺言，然后并行执行？

Question

I am trying to chain series of tasks, that returns a promise, the do parallel execution at the last of the chain. The code below doesn't work, I thought you can pass any object that returns a promise inside "then". Is there a proper way of implementing this. Thank you.

var startTask = $q.when (  );

startTasks
   .then ( validate )
   .then ( savePayment )
   .then ( refetchPayment )
   .then ( saveContactInfo )
   .then ( $q.all ( [ updateStatus, submitOrder ] ) )
   .then ( successHandler )
   .catch ( errorHandler );

Answer 1

Aha, $q.all( [ updateStatus, submitOrder] ) always returns an immediately resolved promise.

What you want to do is probably something like this (guessing)

.then(function(response) {
    return $q.all( [ updateStatus(response), submitOrder(response) ] );
 });

See the difference?

[updateStatus,submitOrder] is just an array of function references, calling $q.all on an array of things that aren't promises will always return an immediately resolved promise.

You need to call those functions, as (I'm assuming) those functions return promises when called.

$q.all takes an array of promises and returns a promise that resolves when all of the promises passed into it are resolved.