How to add footer to perform sum operation in List component

Webix JS
1

Hi Team ,

I have a list in the page , where i want to add the footer which sums up the “consultation fee” value of all the items.

Please find code at below url

http://webix.com/snippet/faec05f3

Appreciate your quick response.

2

Check the updated snippet
http://webix.com/snippet/a5d932b1