Set extent
and/or count
to FALSE
to avoid calculating them if not needed, it might take some time.
The layer information elements are
- dsn
the data source name
- driver
the short name of the driver used
- layer
the name of the layer queried
- layer_names
the name/s of all available layers (see vapour_layer_names)
- fields
a named vector of field types (see vapour_report_fields)
- count
the number of features in this data source (can be turned off to avoid the extra work count
)
- extent
the extent of all features xmin, xmax, ymin, ymax (can be turned off to avoid the extra work extent
)
- projection
a list of character strings, see next
$projection
is a list of various formats of the projection metadata.
Use $projection$Wkt
as most authoritative, but we don't enter into the discussion or limit what
might be done with this (that's up to you). Currently we see
c("Proj4", "MICoordSys", "PrettyWkt", "Wkt", "EPSG", "XML")
as names of this $projection
element.
To get the geometry type/s of a layer see vapour_read_type()
.