topic Re: MapImageLayer, 100s of not-visible sublayers in ArcGIS JavaScript Maps SDK Questions

MapImageLayer, 100s of not-visible sublayers

TonyCollins — Tue, 26 Feb 2019 11:16:44 GMT

Hi,

We are in the process of re-writing a large internal web application that has 100's of users a day. I originally wrote this many years back using v3 (flex) and it is still functioning perfectly today. We are now in the process of a re-write using VueJS and so I am slowly getting intimate with the documentation for v4 but I am unfortunately not finding everything I need.

Onto my question:

We are loading in many MapImageLayers, some with 100's of layers/sublayers. Each of these MapServices have every single sublayer with a default visibility of false so that a user can fire up a LayerList/TOC component and switch them on or off.

The issue, which is probably due to my poor understanding, is that these sublayers do not exist in

mapImageLayer.subLayers.items unless I explicitly define them in the constructor with a visibility of false. I assume this is where findSubLayerById() looks?

Obviously I am unable to know these layer id's up-front so am I missing something obvious on how to add these sublayers correctly without having to specify them?

I can see all the sublayers in mapImageLayer.serviceSublayers but I have not been able to find this property documented so wonder if I should not be touching it?

Thanks for any help

Tony

Re: MapImageLayer, 100s of not-visible sublayers

TonyCollins — Tue, 26 Feb 2019 11:49:06 GMT

Ok, I think I have worked it out but I will leave this here in case I am doing something bad or someone else hits the issue.

It looks like I need to reset sublayers by cloning the service's sublayers.
There is a method called mapImageLayer.createServiceSubLayers documented here:

MapImageLayer | API Reference | ArcGIS API for JavaScript 4.10

Re: MapImageLayer, 100s of not-visible sublayers

TonyCollins — Wed, 27 Feb 2019 13:22:40 GMT

Ignore all this nonsense, the dynamic building of the MapImageLayers were passing in an empty array to baselayers if none were to be displayed which was clearing it!

Sorry!