Call several asynchronous functions and invoke a callback 'after all' of them are done.
You can install it with npm.
npm install after-all
var afterAll = ;var next =;// The above inner function will only be called when all of these asynchronous calls are done;;
More complex example and sample use case
Imagine you have to create a dashboard page which has a list of customers a list products, the total amount of sales and some more information.
Now, the queries to get this information are independent, yet we tend to wait for one to be finished to start the next. We may be able to increase the performance by starting some of this queries at the same time and waiting for the callbacks.
We can use after-all to do something like this.
As you can see, passing a callback to the
next function is optional and it can be
useful to not pass any when you are doing more than one sequetial async operations as
in the example above.
Also notice that all the calls to
next must be done on the same tick.
If an error is passed as the first parameter to the
next callback, the
final callback will be called immediately and the error will be passed to
it as the first argument.