Kaliber {{bs-select}} load data souce on demand

I'm trying to load the data source of my {{bs-select}} on demand. My current code is,

 {{bs-form-element controlType="select" choices=listPayment choiceLabelProperty="description" choiceValueProperty="paymentTermId" label="Payment Term" value=selectedPaymentTerm}}

the value of listPayment is already loaded in this, so what I want is when I click the element it will call a function that will populate the the value of listPayment. Is it possible?