Running a function after loading an external script

Question

Is there a better way, with JavaScript ES6, to load a script and then run a function after that script is ready? Basically loading the script through JavaScript, waiting until it's ready to use, then running a function that might methods etc. from the loaded script.

For instance, a simple way to do this with jQuery is:

$.getScript('foo.js', function() {
   runFunction();
});

Is there a reliable alternative to this?

Answer 1

Yes. You should use a Promise . Specific to network related requests, see the Fetch api: https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API

fetch('http://example.com/movies.json')
  .then(function(response) {
    return response.json();
  })
  .then(function(myJson) {
    console.log(myJson);
  });