Subtotals are working fine now!
Just one thing: I'm in Europe, and I need to format the numbers with comma for decimal separator, period for thousands separator and to use the Euro sign.
I have a function formatNumber that takes a number as an argument, to do just that.
But how do I pass the total to the summary. This is what I tried without luck:
summary: {
type: ["sum"],
title: ["<b style='font-weight:bold;'>Total :</b> formatNumber({0}, 2, ',', '.')"]
}