geography_as_geojson()

Datum geography_as_geojson

(

PG_FUNCTION_ARGS

)

Definition at line 476 of file geography_inout.c.

{
        LWGEOM *lwgeom = NULL;
        GSERIALIZED *g = NULL;
        char *geojson;
        text *result;
        int version;
        int option = 0;
        int has_bbox = 0;
        int precision = DBL_DIG;
        char * srs = NULL;
 
        /* Get the version */
        version = PG_GETARG_INT32(0);
        if ( version != 1)
        {
                elog(ERROR, "Only GeoJSON 1 is supported");
                PG_RETURN_NULL();
        }
 
        /* Get the geography */
        if (PG_ARGISNULL(1) ) PG_RETURN_NULL();
        g = PG_GETARG_GSERIALIZED_P(1);
 
        /* Convert to lwgeom so we can run the old functions */
        lwgeom = lwgeom_from_gserialized(g);
 
        /* Retrieve precision if any (default is max) */
        if (PG_NARGS() >2 && !PG_ARGISNULL(2))
        {
                precision = PG_GETARG_INT32(2);
                /* TODO: leave this to liblwgeom */
                if ( precision > DBL_DIG )
                        precision = DBL_DIG;
                else if ( precision < 0 ) precision = 0;
        }
 
        /* Retrieve output option
         * 0 = without option (default)
         * 1 = bbox
         * 2 = short crs
         * 4 = long crs
         */
        if (PG_NARGS() >3 && !PG_ARGISNULL(3))
                option = PG_GETARG_INT32(3);
 
        if (option & 2 || option & 4)
        {
                /* Geography only handle srid SRID_DEFAULT */
                if (option & 2)
                        srs = getSRSbySRID(fcinfo, SRID_DEFAULT, true);
                if (option & 4)
                        srs = getSRSbySRID(fcinfo, SRID_DEFAULT, false);
 
                if (!srs)
                {
                        elog(ERROR, "SRID SRID_DEFAULT unknown in spatial_ref_sys table");
                        PG_RETURN_NULL();
                }
        }
 
        if (option & 1) has_bbox = 1;
 
        geojson = lwgeom_to_geojson(lwgeom, srs, precision, has_bbox);
    lwgeom_free(lwgeom);
        PG_FREE_IF_COPY(g, 1);
        if (srs) pfree(srs);
 
        result = cstring_to_text(geojson);
        lwfree(geojson);
 
        PG_RETURN_TEXT_P(result);
}

References getSRSbySRID(), lwfree(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_to_geojson(), precision, and SRID_DEFAULT.

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