[OpenLayers-Users] Default tile image whilst loading layer

[Andreas Hocevar]

Darren Karstens wrote:
> Hi,
> The layers of my map load quite slowly and so I need a way of informing my
> users that the map is still loading. I have had a look at the LoadingPanel
> addon which looks ok but I was wondering if there is a way of having a
> loading message on the blank tiles that havent been loaded yet? Is there a
> way to specify a default image for the tiles whilst they are loading?
>   

You could define the css class .olTileImage with a background image. 
This would, however, only work well for non-transparent layers, 
otherwise you would still see the background image. You could redefine 
the .olTileImage class programmatically in a loadend handler of the 
layer though.

I think a more user friendly way to handle this is to make the layers 
load faster, e.g. by grouping layers from the same service into one 
OpenLayers.Layer instance (e.g. for WMS using multiple layer names in 
the layers param), or by installing a tile caching engine like 
GeoWebCache or TileCache on the server.

Regards,
Andreas.

-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.