Downloading Images - FileReference download error 2176

Question

Hi everyone.
I'm trying to download some images but getting this error "Error #2176: Certain actions, such as those that display a pop-up window, may only be invoked upon user interaction, for example by a mouse click or button press."
The trouble is, it IS running off a button click - just indirectly.
I'm trying to design a good architecture for my program, so have the Application, a dataStore and some value objects, for example, a pricebook containing and array of products, each called PricebookVO and ProductVO.
What I'm doing when the application loads is doing a database query with another API that gives me a pricebook and all of its products, and i populate the value objects.  Relationship is obviously  PricebookVO -< ProductVO.  I wanted to download the images for the products at the same time but it won't let me due to the error above, so what I have now is a button bar and when the user clicks a button an event is bubbled up to the Application which changes the page, but what also happens is it checks to see if the user has clicked the Products button and if it has, it tells the PricebookVO to tell each of its ProductVO's to download their image (from a URL that was saved from the query.
Presumably the error im getting now is because the download is not directly summoned by a user event but by an indirect event (ie user pushes button, code calls code which tries to download the file).  How can I download the images and still maintain my architecture?
Also, am I getting confused?  I want to get a file from a server and save them in an mx.controls.Image on the ProductVO record, do I use the FileReference.Download method or something else?  Because on further inspection it looks as though the download method is for downloading something to the local machine with a download dialog box?
Thanks
Steven

Answer 1

Thanks for all your help Peter, its much appreciated.  I hate that useless feeling when learning a new language!
So anyway, I was initially using image.source but thought to myself that's probably referencing the image from its server source which might be quite a hog, so wanted to store it myself, but if you say image.source does indeed handle the image itself and not just reference it from the source, thats good.
My only remaining query is regarding how it is displaying.  I have a tileList which is rendering the images and it does work, however the images are loading on screen as I watch them, and if I scroll I then have to wait again whilst the images load.  If I then scroll back to the previuos part of the screen, where the images had previously already loaded, they have disappeared again and I once again have to wait for them to load.
I know normally you'd embed them, but dont see how thats possible with the way I'm having to load them from the server?
I have a method in my datastore like this:
public function getProds():ArrayCollection{
var imgs : ArrayCollection = new ArrayCollection();
for each (var pb : PricebookVO in pricebooks){
  pb.getProdCount();
  for each (var p2 : ProductVO in pb.products){
   imgs.addItem(p2);
return imgs;
and in my products page:
<mx:TileList>
  <mx:width>100%</mx:width>
  <mx:height>100%</mx:height>
  <mx:itemRenderer>components.Thumbnail</mx:itemRenderer>
  <mx:dataProvider>{DataStore.getInstance().getProds()}</mx:dataProvider>
</mx:TileList>
components.Thumbmail is
<mx:Image>
  <mx:width>100</mx:width>
  <mx:height>75</mx:height>
  <mx:source>{this.data.image.source}</mx:source>
  <mx:toolTip>{this.data.prodCode}</mx:toolTip>
</mx:Image>
So, how can I stop the tilelist from having to constantly reload the images?  I get the impression that the solution might end up using a lot of memory to store the images somehow, so advice on the best way to do this is appreciated.
Thanks!