Failed to parse filter expression:"name" in TextSymbolizer in style 's

Mike_Bresnahan · 2010-01-07T01:32:25.000Z

I was, for many weeks, successfully rendering OpenStreetMap using generate_tiles.py following the instructions on the wiki. Then today I upgraded everything to latest and greatest, including the data. Now when I try to run generate_tiles.py I get the error below. I am seeing this error both on both Fedora 9 64bit and Mac OS X 10.5.

[a715139@devweb2 mapnik]$ ./generate_tiles.py
render_tiles( (-180.0, -90.0, 180.0, 90.0) /home/a715139/mapnik/osm.xml /var/local/osm/ 0 5 World )
Traceback (most recent call last):
File “./generate_tiles.py”, line 195, in
render_tiles(bbox, mapfile, tile_dir, 0, 5, “World”)
File “./generate_tiles.py”, line 126, in render_tiles
renderer = RenderThread(tile_dir, mapfile, queue, printLock, maxZoom)
File “./generate_tiles.py”, line 59, in init
mapnik.load_map(self.m, mapfile, True)
RuntimeError: Failed to parse filter expression:“name” in TextSymbolizer in style ‘stations’

The offending XML looks like this:

<Rule>
  <MaxScaleDenominator>50000</MaxScaleDenominator>
  <MinScaleDenominator>25000</MinScaleDenominator>
  <Filter>[railway]='halt' or [railway]='tram_stop' or [aerialway]='station'</Filter>
  <TextSymbolizer name="name" face_name="DejaVu Sans Book" size="8" fill="#66f" dy="-8" halo_radius="1" wrap_width="0"/>
</Rule>

I know very little about how mapnik works, so I did some research, but I still don’t understand the error message. It appears to be complaining that the string “name” is unparsable, but as far as I can tell it is legal mapnik code.

I compiled mapnik from the latest svn sources and also have the latest OSM mapnik stuff from svn.

Any help would be appreciated.

Ldp · 2010-01-07T02:12:37.000Z

You appear to have recompiled mapnik, and are still on svn trunk. This now holds the development code, nicknamed Mapnik2, that will become version 0.8 at a later stage. This version has some changes to the stylesheet syntax. You ran into one. To make your stylesheet work, you encapsulate a value you want to fill in from the Datasource, like name, in []. So you now write “TextSymbolizer name=”[name]" … />.

Or, do what we all do to keep compatible with 0.6.1, and switch over to the 0.7 branch.

See http://lists.berlios.de/pipermail/mapnik-users/2009-December/002645.html

Mike_Bresnahan · 2010-01-07T03:17:01.000Z

Ah ha! Yes, that was my problem. Thank you very much!

Ldp · 2010-02-02T19:12:02.000Z

For completeness, let me add that the current mapnik trunk code can read the older stylesheets again. It will emit a deprecation warning when it encounters the situation as mentioned above, but still work.