CODEWITHSUNDEEP
javascriptasynchronousecmascript-6
user2036108
user2036108

Reputation: 1307

Call super inside asynchronous callback

I'm currently trying to run an asynchronous function with a callback inside of my constructor. I then need to get data from that callback and use it when creating an instance of the class. My code currently looks like this:

class Foo extends Bar {
    constructor(data) {
        someAsyncCall((response) => {
            data.a = response;
            super(data);
        });
    }
}

Any help is greatly appreciated :)

Upvotes: 0

Views: 334

Answers (1)

Andrew Osborn
Andrew Osborn

Reputation: 221

In my opinion I wouldn't do it inside the constructor. Use the Q library and another helper class as a data access layer. 

HelperClass.getFooById(id)
    .then(function (data) {
        return new Foo(data);
    })

The getFooById method would use Q.defer() and would call Q.resolve(data) once the data is resolved.

If you do it inside of the constructor you can never create an instance of that class without making a request, even if you have the data already.

Q Library: https://github.com/kriskowal/q

Upvotes: 1

Related Questions