How to determine whether a layer is on but outside the scale range

StephenLead

Is there a way to determine whether a layer is switched on, but is not currently shown due to the scale threshold?

See the attached file for an example. When the map first loads, the counties layer is "on" but is not shown due to the map scale. Zoom in a level and and the counties appear.

How can I determine this programmatically? featureLayer.visible returns "true" at all scales. featureLayer.onVisibilityChange doesn't fire when the scale threshold is crossed.

The workaround is to check the current map scale (by finding the LOD and figuring out the corresponding scale?) and compare it to the layer's minScale and maxScale. This seems like a clumsy workaround - is it the only option?

Thanks,
Steve

test.html.zip

EugeneStaten_0-1775261055403.png

JeffPace1

Is there a way to determine whether a layer is switched on, but is not currently shown due to the scale threshold?

See the attached file for an example. When the map first loads, the counties layer is "on" but is not shown due to the map scale. Zoom in a level and and the counties appear.

How can I determine this programmatically? featureLayer.visible returns "true" at all scales. featureLayer.onVisibilityChange doesn't fire when the scale threshold is crossed.

The workaround is to check the current map scale (by finding the LOD and figuring out the corresponding scale?) and compare it to the layer's minScale and maxScale. This seems like a clumsy workaround - is it the only option?

Thanks,
Steve

This clumsy workaround is the only one I could come up with as well, due to the exact limitation you listed. When i layer loads, i check the min/max of all the component layers of the service.  We had people complain about not being able to see greyed out text, so we color coded green for visibile, yellow for partially visible (some sublayers on, some off) and red for hidden due to scale dependencies.

http://www.mymanatee.org/gisapps/mapviewer/

You can see in our "Live Maps" TOC widget the color coded scale icons.  We also incorporated legend thumbnails.