Jukka, could you live with all attributes being read as Strings for now? ..ede
On 27.06.2016 08:35, Jukka Rahkonen wrote: > Hi, > > Json datatypes http://www.tutorialspoint.com/json/json_data_types.htm do not > map perfectly with OJ datatypes. Strings can be separated from numbers, > though, but there is another problem in missing schema. Each feature can have > different attributes. > > I believe that GDAL is scanning the GeoJSON file twice for finding all the > attributes which appear in the data and analyzing their datatypes. Rather > often GeoJSON is converted from GIS data and then schema is fixed so that all > features have same set of attributes and empty ones are marked as NULL. Still > it is hard to know the type of attribute if it is NULL. > > Code for reading GeoJSON with GeoTools is at > https://github.com/geotools/geotools/tree/master/modules/unsupported/geojson > > An easy start could be to read the first one feature and build schema with > attribute types double, string, boolean. But what to do if there are null > values? Read first hundred? Read until first not null? Or let user make a > header line with schema into a separate file "basename.jsont" like with the > GDAL CSV driver http://www.gdal.org/drv_csv.html > > attr_1:string;attr_2:integer;attr_3:double > > Sorry that I can't give simple answers, I thought it would be easier and > handled by JTS already. > > -Jukka- > > edgar.sol...@web.de kirjoitti 2016-06-26 17:19: >> hey Jukka, >> >> attributes do not seem to carry a type in GeoJSON.. any idea how this >> is supposed to be parsed? >> >> ..ede >> >> On 23.06.2016 16:20, Jukka Rahkonen wrote: >>> Hi Ede, >>> >>> Please find attached. I included some small samples in both JML and >>> GeoJSON. For the conversion I used ogr2ogr: >>> >>> ogr2ogr -f geojson output.json input.jml >>> >>> Test data is not perfect: >>> >>> - I just digitized some features and they may be outside the real area of >>> the EPSG:4326 which is default in GeoJSON (-90,-180,90,180) >>> - GDAL warned that DateTime type is not natively supported >>> >>> For handling projections with ogr2ogr use source and target srs parameters >>> as >>> >>> ogr2ogr -f geojson -s_srs epsg:3067 -t_srs epsg:4326 output.json input.jml >>> >>> -Jukka- >>> >>> edgar.sol...@web.de kirjoitti 2016-06-23 15:56: >>>> Jukka, >>>> >>>> do you have an example dataset to tiner with for me? >>>> >>>> ..ede ------------------------------------------------------------------------------ Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
