To add, note that the forthcoming WFS 1.2 (which will then be an OGC/ISO standard) will support paging. This could be awhile, but at least this feature is acknowledged by the spec editors/community.
..Tom -----Original Message----- From: [EMAIL PROTECTED] on behalf of Rahkonen Jukka Sent: Sun 20-Apr-08 17:36 To: Brian Mixon; [email protected] Subject: Re: [mapserver-users] MapServer v. 4.10.0 featureid problem -----Alkuperäinen viesti----- Lähettäjä: [EMAIL PROTECTED] puolesta: Brian Mixon > Tom, > Perhaps I should tell you why I'm after the (or any) unique AND sequential id field for a service's features. I'm trying to page the feature data in a UI and started designing my solution after having read the WFS v 1.0.0 spec. I assumed (yes, I know what happens when one does that (;>)) that I'd just use feature ids. > I should have asked what mechanism MapServer employs to allow me to do something like this (the partial retrieval of features from a large dataset on some service somewhere). I'm going to bring back a certain number of features with each call to a WFS and as the user scrolls through this data I will make subsequent calls to the same service and ask for the next batch of features. > Does this make sense and can you point me in the right direction for getting MapServer to do this? I fear that WFS itself does not support this well. WFS does have a setting for maximum number of features returned by one request, but there is no way to ask for the following set of features starting from, let's say, feature number 100001. But if you take the WFS fid from sequential database field and sort that somehow then it should be possible to reach what you wand by addind a WFS filter like "AND fid>max_fid_from_last_request" to the next WFS request. I can imagine that this could lead to most unuseful result if bounding box is also a part of a filter and user is panning around on the map between the requests (area unvisited before can have features with lower fid values). -Jukka Rahkonen- _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
