topic Re: Typescript error adding sublayers to MapImageLayer in ArcGIS JavaScript Maps SDK Questions

Typescript error adding sublayers to MapImageLayer

LefterisKoumis — Thu, 23 Feb 2023 02:48:47 GMT

I declare a mapimagelayer

const MPl = new MapImageLayer({ ---- ----

Then I created an array of sublayers that need to be visilbe.

I added the sublayers index in an array

thearr.push({ id: 1, visible: true}, { id: 3, visible: true} );

Then, I used:

MPl.sublayers = thearr;

but I got an error

When I used this script without using typescript i have no errors and it runs fine.

Re: Typescript error adding sublayers to MapImageLayer

Noah-Sager — Thu, 23 Feb 2023 13:50:03 GMT

I'm not 100% positive, but I think that if you don't declare the sublayers in the MapImageLayer constructor, you need to use one of the Collection methods to define/add/modify the sublayers.

Collection methods:

https://developers.arcgis.com/javascript/latest/api-reference/esri-core-Collection.html#methods-summary

sublayers property:

https://developers.arcgis.com/javascript/latest/api-reference/esri-layers-MapImageLayer.html#sublayers

Re: Typescript error adding sublayers to MapImageLayer

LefterisKoumis — Fri, 24 Feb 2023 01:54:08 GMT

Thank you. Looking at the documentation, it seems that in JS 4.x is more work to define visible layers of a mapimagelayer. In JS 3.x we could just write this.

lyr.setVisibleLayers([1,2,3])

I assume there is no similar way of doing so in JS 4.x

In a collection like

MPl.sublayers.push(item)

where item or comma-separated list of items cannot be the sublayer id.

Re: Typescript error adding sublayers to MapImageLayer

Noah-Sager — Fri, 24 Feb 2023 16:39:57 GMT

Yes, there is an implementation difference between 3x and 4x. I would highly recommend looking at some 4x samples to get a feel for the difference. These two might be useful:

https://developers.arcgis.com/javascript/latest/sample-code/sandbox/?sample=layers-mapimagelayer-sublayers

https://developers.arcgis.com/javascript/latest/sample-code/sandbox/?sample=layers-mapimagelayer-definitionexpression