topic Group Layer open in Layer List upon map load in ArcGIS JavaScript Maps SDK Questions

Group Layer open in Layer List upon map load

AshleyPeters — Fri, 28 Apr 2023 19:29:27 GMT

I'm working with a single group layer in the layer list widget. By default, the group layer is visible, but collapsed upon map load. For ease of use for the end user, I would like the group layer to be open/expanded when the map loads. I believe I can achieve this by changing the CSS for the widget. I've added this block of code to the style and have tried different things, but haven't been able to get the group layer to be open upon map load. Any assistance is appreciated.

.esri-layer-list__child-toggle .esri-layer-list__child-toggle-icon--opened, .esri-layer-list__child-toggle .esri-layer-list__child-toggle-icon--closed-rtl, .esri-layer-list__child-toggle--open .esri-layer-list__child-toggle-icon--closed { display: none; } .esri-layer-list__child-toggle--open .esri-layer-list__child-toggle-icon--opened { display: block; }

Re: Group Layer open in Layer List upon map load

UndralBatsukh — Fri, 28 Apr 2023 19:55:17 GMT

Hi there,

You don't have to do this via CSS. You can set the LayerList.listItemCreatedFunction to expand the grouplayer on start. The code snippet in the SDK doc shows this and the following is the code.

Hope this helps,

-Undral

Re: Group Layer open in Layer List upon map load

ReneRubalcava — Fri, 28 Apr 2023 19:58:03 GMT

Edit: Beaten by Undral!

You don't need to use CSS for this. You can use the listItemCreatedFunction to iterate through the items in the LayerList and determine which ones you want open by default.

https://developers.arcgis.com/javascript/latest/api-reference/esri-widgets-LayerList.html#listItemCreatedFunction

Demo

https://codepen.io/odoe/pen/PoyKwyw?editors=100

Re: Group Layer open in Layer List upon map load

Justin_Greco — Fri, 28 Apr 2023 20:06:47 GMT

Hi Ashley, you can achieve this by using the listItemCreatedFunction property of the LayerList. Then set open to true for the ListItem for the layer you want expanded.

Re: Group Layer open in Layer List upon map load

AshleyPeters — Fri, 28 Apr 2023 20:38:21 GMT

Wow, thank you all! I looked at actions, but didn't see anything that made sense for a solution. But, that worked like a charm. Always good to learn something new!