Add a function to read in NetCDF attributes

Author: amoeba

NAMESPACE

@@ -40,6 +40,7 @@ export(get_doc_id)
 export(get_identifier)
 export(get_latest_release)
 export(get_mn_base_url)
+export(get_ncdf4_attributes)
 export(get_netcdf_format_id)
 export(get_or_create_pid)
 export(get_package)

R/attributes.R

@@ -0,0 +1,34 @@
+#' Get a data.frame of attributes from a NetCDF object
+#'
+#' @param nc (ncdf4 or character) Either a ncdf4 object or a file path
+#'
+#' @return (data.frame) A data.frame of the attributes
+#' @export
+#'
+#' @examples
+#' \dontrun{
+#' get_ncdf4_attributes("./path/to/my.nc")
+#' }
+get_ncdf4_attributes <- function(nc) {
+  stopifnot(is(nc, "ncdf4") || file.exists(nc))
+
+  # Read the file in if `nc` is a character vector
+  if (is.character(nc)) {
+    nc <- ncdf4::nc_open(nc)
+  }
+
+  attributes <- names(nc$var)
+  result <- data.frame()
+
+  for (i in seq_along(attributes)) {
+    attribute <- ncdf4::ncatt_get(nc, attributes[i])
+    names <- names(attribute)
+
+    for (name in names) {
+      result[i, name] <- attribute[[name]]
+    }
+  }
+
+  result
+}
+