vapour_layer_names: Read GDAL layer names

In hypertidy/vapour: Access to the 'Geospatial Data Abstraction Library' ('GDAL')

Read GDAL layer names

Description

Obtain the names of available layers from a GDAL vector source.

Usage

vapour_layer_names(dsource, ...)

Arguments

dsource	data source name (path to file, connection string, URL)
...	arguments ignore for deprecated compatibility (no 'sql' argument any longer)

Details

Some vector sources have multiple layers while many have only one. Shapefiles for example have only one, and the single layer gets the file name with no path and no extension. GDAL provides a quirk for shapefiles in that a directory may act as a data source, and any shapefile in that directory acts like a layer of that data source. This is a little like the one-or-many sleight that exists for raster data sources with subdatasets (there's no way to virtualize single rasters into a data source with multiple subdatasets, oh except by using VRT....)

See vapour_sds_names for more on the multiple topic.

Value

character vector of layer names

Examples

file <- "list_locality_postcode_meander_valley.tab"
mvfile <- system.file(file.path("extdata/tab", file), package="vapour")
vapour_layer_names(mvfile)

hypertidy/vapour documentation built on March 2, 2024, 7:59 p.m.