KendoUI Grid custom groupable object - kendo-ui

Question

I am trying to make a grid groupable on columns field but the columns are object.
{
Gestionnaire :
{ id: 4, nom:'nomgestionnaire'},
{..},
..
}
I have success for sortable:
columns: [
field: "Gestionnaire"
title: "Gestionnaire"
sortable:
compare: (a,b) =>
#compareColumnFields(a.Gestionnaire.Nom, b.Gestionnaire.Nom)
]
with #compareColumnFields function is :
if a is b
return 0
else if a > b
return 1
else
return -1
and for groupable?
groupable : ...

Answer 1

I think you're wanting to allow the user to actively group columns.
In that case, all you need is:
groupable: true
in the main structure of the grid.
For example:
$('#grid').kendoGrid({
columns: [
{
fields: "Guestionaire",
title: "Guestionaire",
sortable:
compare: (a,b) =>
#compareColumnFields(a.Guestionaire.Nom, b.Guestionaire.Nom)
},
{...placeholder for other columns...}
],
groupable: true
});
Kendo has a sample of this at http://dojo.telerik.com/ejehe
Ignore the SelectRow and Expand/Collapse stuff and that ought to be the same as what you're trying to accomplish.

Answer 2

For those in the same situation as me , I completely change solution. Instead of making me a function that returns true and false , it giving it the object in full, I just give the string .
For my example I give directly a.Gestionnaire.Nom and b.Gestionnaire.Nom, and THEN you can call :
groupable: true
In fact it was obvious.