Returns an updateable Model object for the item at the specified index in the data list.

var dataSource = new shield.DataSource({
    read: "/get_all.php",
    modify: {
        create: "/handle_updates.php",
        update: "/handle_updates.php",
        remove: "/handle_updates.php"
    schema: {
        fields: {
            Id: { path: "id", type: Number },
            Name: { path: "name", type: String }

// get an editable model for the second item
var model = dataSource.edit(1);

// update the Id property of the item via the Model.set() method
// the first parameter to that method is the path to update 
// and the second is the value
model.set("Id", 1001);

// update the Name property of the item directly through the data
model.data.Name = "New Name";

// save the changes