Using this set in constructor in then

Question

Is it possible to set this.variable in then? I know I can pass a regular variable, but can this be done with one set in the constructor as well?

class Test {
    constructor() {
        this.variable = false;
    }

    aFunction() {
        someExternalThing(document.body, {
            option: 1
        }).then(function () {
            this.variable = true;
        });
    }
}

You can if the callback has the correct this: https://stackoverflow.com/q/20279484/3001761 — jonrsharpe, Dec 31 '20 at 11:08

score 1 · Accepted Answer · answered Dec 31 '20 at 11:14

1

Yes it is possible, what you will need to change in your code is the declaration of the .then () parameter function

You must use arrow function for this to keep the class reference

Ex:

.then(() => { ... }

answered Dec 31 '20 at 11:14

Henrique Viana

645
4
12

score 0 · Answer 2 · answered Dec 31 '20 at 11:36

0

The this keyword is referring to the function. Try this:

aFunction() {
  const that = this;
  someExternalThing(document.body, {
     option: 1
  }).then(function () {
     that.variable = true;
  });
}

answered Dec 31 '20 at 11:36

Azure

127
11

Using this set in constructor in then

2 Answers2