Hi all I have just tested QGIS master build againt GDAL "trunk" (build via a git clone from GDAL github repository & following the doc instructions [1] ). It works like a charm with a small roads dataset.
Thanks Even (and other involved devs and funders ) for making this happen ! I have seen one first caveat : * Export a Shapefile to GeoJSON in QGIS via the "Save as" and choose to keep only 1 number for decimal precision * Open this GeoJSON file, toggle edition, and add a new feature * The new feature geometries are written with default decimal precision (for example : 6790978.453365888446569 ) and not like the other original features ( for example : 6790978.4 ) We should have a way in QGIS to keep the original decimal precision. Any clue on this ? Should I open a ticket ? Regards Michaël [1] https://trac.osgeo.org/gdal/wiki/BuildingOnUnix 2016-01-14 20:57 GMT+01:00 Even Rouault <[email protected]>: > Le jeudi 14 janvier 2016 20:38:04, Nyall Dawson a écrit : > > On 15 Jan 2016 2:39 AM, "Even Rouault" <[email protected]> > wrote: > > > A more "streaming-like" approach for the driver not proceeding to full > > > ingestion of features could be desirable to remove that limitation, but > > > > that's > > > > > more involved. A possibility could be to have a "at-hand" parser to > > > > delimitate > > > > > JSon "Feature" objects and use only json-c to parse each feature. But > > > > GeoJSON > > > > > is certainly not the more appropriate file format to deal with huge > > > > datasets... > > > > > > Even, > > > > Editable GeoJSON in OGR is great news! > > > > I've got a question regarding the geojson driver you may be able to > assist > > with. Is there any method in the OGR libraries which allow direct parsing > > of a string to a layer? (Ie, without first writing it out to a file). > > > > I'd like to add the ability to directly paste geojson text into QGIS and > > have it inserted as a feature in the current layer (like how you can > > currently paste WKT text as a feature). I don't want to have to manually > > parse the json (that would be a nightmare). > > Well, the GeoJSON driver support "filenames" which are in fact GeoJSON > content: > > $ ogrinfo > '{"type":"Feature","properties":{"foo":"bar"},"geometry":{"type":"Point","coordinates":[2,49]}}' > -ro -al > > Layer name: OGRGeoJSON > Geometry: Point > Feature Count: 1 > Extent: (2.000000, 49.000000) - (2.000000, 49.000000) > Layer SRS WKT: > GEOGCS["WGS 84", > DATUM["WGS_1984", > SPHEROID["WGS 84",6378137,298.257223563, > AUTHORITY["EPSG","7030"]], > AUTHORITY["EPSG","6326"]], > PRIMEM["Greenwich",0, > AUTHORITY["EPSG","8901"]], > UNIT["degree",0.0174532925199433, > AUTHORITY["EPSG","9122"]], > AUTHORITY["EPSG","4326"]] > foo: String (0.0) > OGRFeature(OGRGeoJSON):0 > foo (String) = bar > POINT (2 49) > > Works also with FeatureCollections. > Alternatively, you could also put the content in a in-memory GDAL file > (/vsimem/ virtual file system) and open it. > > So you could likely instanciate a temporary layer and get a QGIS feature > from that. > > > If you are just interested in geometries and not attributes, there's also > the C function : > > OGRGeometryH OGR_G_CreateGeometryFromJson (const char *); > > > > > > If I could somehow take advantage of OGR's geojson driver to do the heavy > > lifting then this work would be trivial. > > > > Any ideas? > > > > Nyall > > -- > Spatialys - Geospatial professional services > http://www.spatialys.com > _______________________________________________ > Qgis-developer mailing list > [email protected] > List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer >
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