This conversation reminds of me of what we're doing in our applications at NREL. We're making use of a custom hybrid application consisting of mapserver, tilecache, and featureserver to render our map tiles and serve vector features. We've developed some pretty complex use cases where we need to retrieve the result of a bbox query in difference formats as well doing some geoprocessing (simplification mostly, but also complex clustering).
Using featureserver as our "vector layer framework" has been great. Each of our layers has its own config file and we can develop really complex service chains that use whatever python classes that we want. For example take a point layer: pointsA In our FS config we have a datasource defined as: [pointsA] type=OGR dsn=/path/to/the/file/pointsA.shp layer=pointsA this gives us the ability to get at the points in whatever format we want and perform spatial queries. FeatureServer is great (and beautifully restful). So let's say we want to be able to access the buffer of each point. We'd define a process and the a new layer in which each feature requested is first passed through that process. [process_buffer] module=Buffer class=Buffer buffer_default=0.1 buffer_locked=no and then we have a new layer: [pointsA_buffers] type=OGR dsn=/path/to/the/file/pointsA.shp layer=pointsA processes=buffer So now when we access the "pointsA_buffers" layer the features are the same as "pointsA" but are buffered by whatever distance we've passed in via the URL. The utility of this is huge! You can write any number of "processes" and simply add them into your featureserver config. You can also chain several together, the possibilities are endless and wonderful. We're starting to employ this method using shapely and OGR to do all of the geoprocessing. Chris On Oct 18, 11:27 am, Brent <[email protected]> wrote: > I would love to see something like the pypes framework incorporate > some geoprocessing. I am not familiar with it, but it seems to have a > FME feel to it.http://www.pypes.org/ > > Brent > > On Oct 15, 8:41 am, Sean Gillies <[email protected]> wrote: > > > Hi all, > > > I launched this group soon after chatting with a bunch of different > > folks about feature processing. Mainly in the context of WPS services. > > I don't do a lot of what GIS people call "geoprocessing" these days, > > but enjoy thinking about it. I wonder if we might be able to move past > > one-off scripts to frameworks for processing like we've moved past one- > > off CGI scripts to web frameworks. What would a geoprocessing > > framework look like? Does anyone have one they'd like to introduce? > > FWIW, I think a WPS service isn't a framework by itself, but could be > > backed up by a framework. > > > Cheers, > > > -- > > Sean > >
