TOC Legend 4.x

[RichardMoussopo]

Would be nice to have the Legend similar to Legend in Desktop apps (ArcGIS Pro, ArcMap) as a widget in ArcGIS API for JavaScript. 

[JuliePowell]

Hi Richard, have you seen this sample? Does it meet your requirements?

https://developers.arcgis.com/javascript/latest/sample-code/widgets-layerlist-legend/

Julie

[KristianEkenes]

Yes. This is already offered in the LayerList widget panels. 

// displays the legend for each layer list item
const layerList = new LayerList({
  view: view,
  listItemCreatedFunction: function(event){
    const item = event.item;
    item.panel = {
      content: "legend"
    };
  }
});

[BjornSvensson]

This was implemented in version 4.7 (April 2018).