updateItem

updates the data item with new properties

function updateItem(
    // the item ID
    id: number|string,
    // the object with properties
    data: object
): void

var id = dgrid.getSelectedId();
var item = dgrid.getItem(id.row);
item[id.column] = "some_new_value";

dgrid.updateItem(id.row, item);

also check the next samples: