[OpenLayers-Users] Overriding overlay select to force a reload of the toggled layer

[Adrian Popa]

Hi everybody,

I have several overlay vector layers that get their data in KML format 
from some server-side scripts. The data is highly dynamic, so it needs 
to be refreshed constantly (this is solved). The problem appears if only 
one overlay layer is selected (visible), I need to refresh all overlay 
layers so that if the user toggles another overlay, he will have the 
most recent data. I would like to reduce the overhead on the server and 
client side and only refresh the visible overlay layers, and to force a 
refresh of a layer whenever the user makes it visible. For this I would 
have to override the function that runs when a layer is selected in the 
layer switcher and call another refresh function before the layer is 
made visible. Can anyone point me in the right direction?

P.S. I would like to do this without editing the openlayers code; 
instead I would like to override/overload the function for my objects only.

Thanks,
Adrian