topic Re: ArcGIS API 4.6 How to set opacity for the basemap? in ArcGIS JavaScript Maps SDK Questions

ArcGIS API 4.6 How to set opacity for the basemap?

BlairJones — Tue, 05 Jun 2018 20:03:00 GMT

ArcGIS API 4.6 What is the "proper" way to change opacity for the basemap?

possibly:

var map = new Map({ basemap:"topo"});

map.allLayers.items[0].opacity=0.25;

or perhaps:

var map = new Map();

map.add( new TileLayer(

id:"topo",

url="https://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer"

});

map.findLayerById("topo").opacity=0.25;

Appendix question: why use basemap vs TileLayer ?

Thanks and good health!

Blair

Re: ArcGIS API 4.6 How to set opacity for the basemap?

RobertScheitlin__GISP — Tue, 05 Jun 2018 20:35:54 GMT

Blair,

You can grab the basemap layer as you have in your first code block because you can always count on the the main basemap layer being 0 index but if you are using a basemap with reference layers you will have to adjust that logic. You can use map.baseLayers.forEach(layer) to set the opacity for each of the layers in the basemap. The reason you would use a basemap vs a TileLayer is mainly for the ease of coding using one line of code to set the basemap verses using a the TileLayer route.

Re: ArcGIS API 4.6 How to set opacity for the basemap?

arahman_mdmajid — Wed, 19 Jan 2022 09:02:20 GMT

One more important thing to note is that you also have to wait until the view is ready and then access the basemap layer; otherwise, it will give you undefined.

view.when(function(){ console.log(map.allLayers.length); console.log(map.basemap.baseLayers.getItemAt(0)); map.basemap.baseLayers.getItemAt(0).opacity = 0.6; });