Ticket #31 (closed defect: fixed)

Opened 5 years ago

Last modified 5 years ago

GeoSPARQL datatypes

Reported by: charnik Owned by: charnik
Priority: major Milestone: Support for GeoSPARQL 1.0.1
Component: generaldb Version: 3.2.6
Keywords: GeoSPARQL, dataypes, wktLiteral, geometry Cc:

Description

When storing RDF data with geometries specified with the datatypes of GeoSPARQL, they are stored as ordinary datatype literals and are ignored by Strabon. Strabon should handle them like it handles strdf:WKT literals, thus storing them in geo_values table and querying them appropriately.

Change History

comment:1 Changed 5 years ago by charnik

  • Owner changed from pyravlos-team to charnik
  • Status changed from new to assigned

comment:2 follow-up: ↓ 5 Changed 5 years ago by charnik

When parsing literals with datatype geo:wktLiteral, we should consider parsing it the way GeoSPARQL requires, e.g., checking whether the URI of CRS appears before the geometry. The CRS and the geometry should be separated with *one or more spaces* (Unicode U+0020 character).

comment:3 Changed 5 years ago by charnik

We should also implement requirement Req. 11 (/req/geometry-extension/wkt-literal-default-srs
): The URI <http://www.opengis.net/def/crs/OGC/1.3/CRS84> shall be assumed as the spatial reference system for geo:wktLiterals that do not specify an explicit spatial reference system URI.

Notice that Strabon uses <http://www.opengis.net/def/crs/EPSG/0/4326> (WGS 84 geodetic latitude-longitude) as the default CRS and not <http://www.opengis.net/def/crs/OGC/1.3/CRS84> (WGS84 geodetic longitude-latitude) as GeoSPARQL requires.

comment:4 Changed 5 years ago by charnik

We should also implement requirement Req. 13 (/req/geometry-extension/wkt-literal-empty
): An empty RDFS Literal of type geo:wktLiteral shall be interpreted as an empty geometry.

comment:5 in reply to: ↑ 2 Changed 5 years ago by charnik

Replying to charnik:

When parsing literals with datatype geo:wktLiteral, we should consider parsing it the way GeoSPARQL requires, e.g., checking whether the URI of CRS appears before the geometry. The CRS and the geometry should be separated with *one or more spaces* (Unicode U+0020 character).

Fixed in changeset 914:a83d7023a89b.

comment:6 Changed 5 years ago by charnik

  • Status changed from assigned to closed
  • Resolution set to fixed
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