Async/Await callbacks
Intro.js main functions to start/stop a tour return a Promise object. You can also return a Promise object in the callback functions
(e.g. onbeforechange) and Intro.js internally waits for that Promise object to be fulfilled. You can use this concept to perform async I/O (e.g. sending HTTP calls) before moving to the next step of the tour.
In the following example, we are returning a Promise object and we resolve it after 500ms:
introJs().onbeforechange(async () => {
return new Promise((resolve) => {
console.log('Performing I/O...');
setInterval(resolve, 500);
});
}).start();