Hi, 2009/3/22 Andrew Smith <laconi...@gmail.com>: > Andreas, you mentioned that if my data was in PostGIS I could use either a > WMS or WFS to get the data. If I went down the WMS path, I would have one > WMS for my base map layer, and another one for my text objects layer. My
You could also combine these into one set of image tiles. WMS has a layers parameter. So if your wms layer params has something like params.layers=["mybaselayer","myoverlay"]; in it, both will be rendered in one image, with the overlay not occluding the base layer. > understanding is that the text WMS would return a tile map of images which > would be largely empty space with the occasional text value here and there. > I guess this layer would be transparent so as not to occlude the underlying > map images. That's correct, you would have to add the transparent=true param for the overlay. > Meanwhile, the WFS would return the details about the text > labels and rely on OpenLayers to actually render the vector representations. You can also get the details of text labels using a WMS GetFeatureInfo request. > You mentioned that WMS would be preferred if there were a 'huge number of > features' - I'm surprised that creating all those image tiles on the server > side is faster than adding x vector objects on the browser side (I will > probably have a few dozen at most). Is there a certain point where it just > makes more sense to do it on the server based on the number of objects you > want to display? If you expect the number of your point to grow beyond ~100, you'll definitely be better off using WMS (especially if your users are on Internet Explorer). Regards, Andreas. -- Andreas Hocevar OpenGeo - http://opengeo.org/ Expert service straight from the developers. _______________________________________________ Users mailing list Users@openlayers.org http://openlayers.org/mailman/listinfo/users