Hello, in Video 17: Customizing Item Renderers: http://www.adobe.com/devnet/flex/videotraining/xml/vid17.html
It shows an example where it's overriding the built-in data property's setter method. If you jump to 6:20mins you will see what I mean.
How is this being called? Does the DataGrid automatically set the data property for the next item of data to be rendered and then it's invoked?...
... This to me seems like it's making lots of network calls, therefore a very chatty flex app... Surely you wouldn't do this approach to decide whether to show an image or a place-holder? Would you not pre-populate the DataGrid data with the relevant URLs to load using server-side logic so the Flex app doesn't need to make these network-heavy decisions?
Internally Flex passes data to renderers in the "data" property, so it happens behind the scenes. It actually works pretty efficiently.
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