How to replace watchUtils.whenFalseOnce to the equivalent in reactiveUtils

Question

Hello,

We have a code chunk that works - taken from a post by @RobErt Scheitlin, but uses watchUtils which is deprecated.

watchUtils.whenFalse(view, 'stationary', (evt) => {
        if (!view.stationary) {
            watchUtils.whenTrueOnce(view, 'stationary', function (evt) {
                console.log(view.extent);
            });
        } else {
            watchUtils.whenFalseOnce(view, 'interacting', function (evt) {
                console.log(view.extent);
            });
        }
    })

How should we convert it to using the reactiveUtils tools?

Thank you in advance,

Marcelo

ReneRubalcava · Accepted Answer

The reactiveUtils have an option object you can provide where you can set "once" to true.

https://developers.arcgis.com/javascript/latest/api-reference/esri-core-reactiveUtils.html#ReactiveListenerOptions

Your above code snippet would look something like this, but the way you have it written, the else is unreachable, maybe the main is watch and not whenFalse?

when(
		() => !view.stationary,
		() => {
			console.log("view stationary is: ", view.stationary);
			when(
				() => view.stationary,
				() => console.log("view is now stationary"),
				{ once: true }
			);
		}
	);

Here is a codepen with both options.

https://codepen.io/odoe/pen/zYLwKGb?editors=0010