Kendo Grid - How to translate text "is true", "is false" in the column header? - kendo-ui

Question

I have following column header in the grid (see image below):
I would like to ask, how can i translate "is true", "is false" strings?
Many Thanks for any advice.
Columns:
{
field :"active",
title : $translate.instant('ACTIVE'),
width:150,
filterable: {
cell: {
operator: "contains"
}
}
},
Model:
active: {
editable: true,
nullable: false,
type: "boolean"
},

Answer 1

You should define in your filterable the following messages:
filterable: {
mode: "row",
messages: {
isFalse: "es falso",
isTrue: "es verdadero"
}
},
See it in action in the following snippet:
$(document).ready(function () {
$("#grid").kendoGrid({
dataSource: {
data: products,
schema: {
model: {
fields: {
ProductName: { type: "string" },
UnitPrice: { type: "number" },
UnitsInStock: { type: "number" },
Discontinued: { type: "boolean" }
}
}
},
pageSize: 20
},
height: 550,
scrollable: true,
sortable: true,
filterable: {
mode: "row",
messages: {
isFalse: "es falso",
isTrue: "es verdadero"
}
},
pageable: {
input: true,
numeric: false
},
columns: [
"ProductName",
{ field: "UnitPrice", title: "Unit Price", format: "{0:c}" },
{ field: "Discontinued", template: "#= Discontinued ? 'verdadero' : 'falso' #" }
]
});
});
<link href="http://cdn.kendostatic.com/2014.2.1008/styles/kendo.common.min.css" rel="stylesheet" />
<link href="http://cdn.kendostatic.com/2014.2.1008/styles/kendo.default.min.css" rel="stylesheet" />
<script src="http://cdn.kendostatic.com/2014.2.1008/js/jquery.min.js"></script>
<script src="http://cdn.kendostatic.com/2014.2.1008/js/kendo.all.min.js"></script>
<script src="http://demos.telerik.com/kendo-ui/content/shared/js/products.js"></script>
<div id="grid"></div>

Answer 2

Based on kendoDocs you should do it like this:
...
filterable: {
cell: {
operator: "contains"
},
messages: {
isTrue: $translate.instant('YES'),
isFalse: $translate.instant('NO')
}
}