Binding a promise handler function to an object

Question

I have some code like:

var bar = foo().then(function success(value) {
  // compute something from a value...
}, function failure(reason) {
  // handle an err         


        

Answer 1

If you are only interested in the object this of the enclosing scope, and you are using ECMA6 or later, you could use arrow functions. It would look like:

var that = this;
var bar = foo().then(value => {
  // compute something from a value...
  console.log(this === that); // true
  this.propA = value.propA
});

You could find more examples in MSD Using promises