Yes, sure, having all as strings is a good start. -Jukka-
edgar soldin wrote: > 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/g >> eojson >> >> 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 ------------------------------------------------------------------------------ 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
