Hello Jon, On Sat, Nov 14, 2009 at 10:49 PM, Jon Burgess <jburgess...@googlemail.com>wrote:
> On Sat, 2009-11-14 at 21:58 +0200, Ciprian Talaba wrote: > > I am trying to do some work with the public transport network, and for > > that I need to get the roles (forward/backward mainly) of the route > > members as attributes of ways(lines) in PostGIS. I am using osm2pgsql > > and I hoped to get this done by modifying the default style. I have > > added a new line in the style file "way role text linear" but > > this is not working (maybe it's obvious why not for some of you). > > > > Also I was looking at the osm2pgsql source code and I saw that getting > > information about the cycling network is treated separated in the code > > (in output-pgsql.c), and I was thinking of doing the same for public > > transport. > > > > Do you know if there is a way for doing this with the style, or I have > > to dig more in the code? Any pointers will be appreciated. > > I'm afraid the relation roles are not accessible in the style file. > Pretty much all the relation processing is handled in the C code and > each type of relation needs special handling. > > When a route relation is converted into a postgis geometry all of the > constituent ways are joined into a single linestring. There is no > obvious place where the role of each individual way could be recorded on > this linestring. > > One possibility might be to keep the members as separate linestrings for > and then add an artificial tag, say route_role=... in the output. > > Another approach might be for you to query the planet_osm_rels table > (provided you imported the data in --slim mode). This contains the raw > data listing all the relations and their members. Armed with this > information you could then query the planet_osm_line table to obtain the > geometry for each of these ways (all the members will probably appear as > distinct roads in this table). > > Jon > > > Thank you about this info. I will probably start with the last approach (using planet_osm_rels and planet_osm_line tables) because this will keep my code separate from osm2pgsql. I will try to publish my tries because I believe others will be interested in something like this. Regards, Ciprian
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