Custom format row data for display with string templates or custom functions.
Formatting Row Data for Display
Data can be stored in one format but be displayed in a different format. For instance, prices can be stored as numbers but be displayed as "$2.99", and birthdays can be stored as date objects but be displayed as "12/9/2009".
Simple formatting can be defined with a string template on the column definition.
YUI().use("datatable", function(Y) {
    var table = new Y.DataTable({
        columns: [ "id", "name", { key: "price", formatter: "${value}" } ],
        data   : [
            { id: "ga-3475", name: "gadget",   price: 6.99 },
            { id: "sp-9980", name: "sprocket", price: 3.75 },
            { id: "wi-0650", name: "widget",   price: 4.25 }
        ],
        caption: "Data formatting with string template"
    }).render("#template");
When a calculation is needed, define a custom function that generates markup for the data cell. The custom formatter function receives an object with the properties listed in Appendix B in the DataTable user guide.
// See the DataTable user guide for a list of properties on o.
function calculate(o) {
    return "$" + (o.data.price - o.data.cost).toFixed(2);
}
var table = new Y.DataTable({
    columns: [ "id", "name", { key: "profit", formatter: calculate } ],
    data   : [
        { id: "ga-3475", name: "gadget",   price: 6.99, cost: 4.99 },
        { id: "sp-9980", name: "sprocket", price: 3.75, cost: 2.75 },
        { id: "wi-0650", name: "widget",   price: 4.25, cost: 3.25 }
    ],
    caption: "Data formatting with custom function"
}).render("#function");
The DataType utility can be used to help format date objects.  This example
also uses the emptyCellValue column configuration to supply a custom cell
value in the case of missing data.
YUI().use("datatype-date", "datatable", function (Y) {
    function formatDates(o) {
        return o.value &&
            Y.DataType.Date.format(o.value, { format: "%m/%d/%Y" });
    }
    dt = new Y.DataTable({
        columns: [
            "id",
            "name",
            { key: "date", formatter: formatDates, emptyCellValue: "(unknown)" }
        ],
        data   : [
            { id: "ga-3475", name: "gadget",   date: new Date(2006, 5, 1) },
            { id: "sp-9980", name: "sprocket", date: new Date(2004, 8, 16) },
            { id: "wi-0650", name: "widget"} // no date for this record
        ],
        caption: "Data formatting with DataType.Date"
    }).render("#dates");