Can i add dropdown column at runtime?

Getting help Questions
1

I am able to add the columns at run time
i am providing type as checkbox or dropdown but its showing as text

$scope.columns =[]
$scope.columns.push({
title: ‘Active’,
data: ‘enable’,
type: ‘checkbox’
})

2

At the first glance, it looks fine. Can you build a JSFiddle/JSBin demo with your initialization settings?