The idea is to add in a table of contents widget for the JavaScript API. Right now, there is the legend, then a layer checklist. These two must be combined to prevent the user from having to toggle back and forth between the checklist and the legend. Allow for the symbology to be displayed right next to the check box. Allow for collapsing/expanding the TOC widget and allow for multiple group layers to be supported. Below is an example:
Current end users what an all inclusive TOC and not have to toggle back and forth between two widgets.