[OpenLayers-Users] Layer.Vector with multiple data sources

[Andreas Hocevar]

Alexandre Dube wrote:
> Hi devs,
>
>   I want to discuss about a new feature on Layer.Vector : multiple data 
> sources depending on the zoom level.
>
>   I already developped something very similar : 
> http://dev4.mapgears.com/bdga/bdgaWFS-T.html  At zoom level 0 to 3, you 
> will see vector polygons ( regions ).  Each level comes from a different 
> source that has been normalized to improve the rendering speed.  So, 
> each zoom level has its own vector layer and they are all hidden from 
> the layer switcher.  They are controlled by a dummy layer.
>
>   At first, I thought this was cool, but now that I think about it, a 
> single type of data, the Quebec regions on my example, should be 
> displayed on a single layer.  If I want to interact with my data the way 
> it is now, I need to look at 4 different layers and keep track of a 
> dummy layer also.  A single vector layer with the possibility to give it 
> multiple data sources depending on the zoom level would be much better.  
> What do you think ?  It could be a nice upgrade.
>   

It should be easy to customize the strategy you are using (I assume
Fixed or BBOX) to change the url and/or params of the protocol on the
zoomend event (similar to the moveend event handler in the BBOX
strategy). This strategy would then have to know the urls/params for
each zoom level, and you would just interact with one vector layer.

Regards,
Andreas.

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