Hi @Tom_Prutz, Good evening,
I don't know whether your question is still relevant, as you posted it almost 2 weeks ago...
Actually I think your code snippet should work, so we have got to find out why it is not working - as you say - in your case. You can find more information about reactiveUtils in the ArcGIS JS API Reference, and there it is suggested to put a question mark behind view. But I did test your sample without a question mark, and that did the job as well...
reactiveUtils.when(
() => view?.stationary === true,
() => {
console.log("view is stationary now");
});
To see a working example you have a look at this blogpost ArcGIS JavaScript with UK data - URL.searchParams. It might seem an older post, but I just updated it tonight, to use reactiveUtils (instead of the deprecated, and now even completely removed, watchUtils which I used in an earlier version of the post). As you can see, the parameters in the URL are updated every time the view becomes stationary.
So, in the end, the conclusion might be, that your issue is caused by your test setup. Can you please provide us with more information/code to explain what you are trying to do?
Cheers,
Egge-Jan