[OpenLayers-Dev] new Strategy.OptionsByZoom

Alexandre Dube adube at mapgears.com
Mon Jan 19 16:19:38 EST 2009

Tim Schaub wrote:
> Hey-
> Not sure I get it - but I may have missed the back story.
> Looks like you want to display a different layer (featureType) depending 
> on the scale.
> The current solutions are to
> 1) use multiple layers on the client with scale constraints, or
> 2) configure your server to use different data sources depending on scale.
> Can you describe what is wrong with either of the solutions above?  The 
> first one is particularly easy.
> Tim

Hi Tim,

About your solutions :

1) Multiple layers --> At first, that's what I did. They were all hidden 
from the layerswitcher and I had a dummy layer controlling their 
visibility. That was working well, but then I thought on type of data 
should always be displayed in only one layer. I mean, I want to have one 
road layer to deal with, not 4 and a dummy one. It's simpler that way, 
it think.

2) Configure your server --> You're right about my server(s), but not 
the ones I do not control. I use mapserver, so I could easily GROUP my 4 
layers in my mapfile and request the group name instead of changing 
typenames, but what about servers I don't control ?

Well, in the end I just thought "hey, this might be better to have only 
one OL.Layer than 5" so I wrote it. Do you think it is ?

Alexandre Dubé

More information about the Dev mailing list