IDataRenderer  - AS3 Flex

Components that are used in an item renderer or item editor in a list control (such as the List, HorizontalList, TileList, DataGrid, and Tree controls), or as renderers in a chart are passed the data to render or edit by using the data property. The component must implement IDataRenderer so that the host components can pass this information. All Flex containers and many Flex components implement IDataRenderer and the data property.

In a list control, Flex sets the data property of an item renderer or item editor to the element in the data provider that corresponds to the item being rendered or edited. For a DataGrid control, the data property contains the data provider element for the entire row of the DataGrid control, not just for the item.

To implement this interface, you define a setter and getter method to implement the data property. Typically, the setter method writes the value of the data property to an internal variable and dispatches a dataChange event, and the getter method returns the current value of the internal variable, as the following example shows:

    // Internal variable for the property value.
    private var _data:Object;
    
    // Make the data property bindable.
    [Bindable("dataChange")]
    
    // Define the getter method.
    public function get data():Object {
        return _data;
    }
    
    // Define the setter method, and dispatch an event when the property
    // changes to support data binding.
    public function set data(value:Object):void {
        _data = value;
    
        dispatchEvent(new FlexEvent(FlexEvent.DATA_CHANGE));
    }