From 3d281b1b4bc541e3b7356145a40f81093542910c Mon Sep 17 00:00:00 2001
From: Magnus Ulimoen <magnusu@met.no>
Date: Fri, 17 Jan 2025 16:17:35 +0100
Subject: [PATCH] Add back add_string_variable

---
 netcdf/src/file.rs    | 14 ++++++++++++++
 netcdf/src/group.rs   | 15 +++++++++++++++
 netcdf/tests/types.rs | 20 ++++++++++++++++++++
 3 files changed, 49 insertions(+)

diff --git a/netcdf/src/file.rs b/netcdf/src/file.rs
index 75715e9..b037e18 100644
--- a/netcdf/src/file.rs
+++ b/netcdf/src/file.rs
@@ -472,6 +472,20 @@ impl FileMut {
         super::variable::add_variable_from_identifiers(ncid, name, dims, xtype)
     }
 
+    /// Create a Variable containing strings into the dataset, with no data written into it
+    ///
+    /// Dimensions are identified using the name of the dimension, and will recurse upwards
+    /// if not found in the current group.
+    pub fn add_string_variable<'f>(
+        &mut self,
+        name: &str,
+        dims: &[&str],
+    ) -> error::Result<VariableMut<'f>> {
+        let typ = crate::types::NcVariableType::String;
+        let (ncid, name) = super::group::get_parent_ncid_and_stem(self.ncid(), name)?;
+        VariableMut::add_from_str(ncid, &typ, name, dims)
+    }
+
     /// Flush pending buffers to disk to minimise data loss in case of termination.
     ///
     /// Note: When writing and reading from the same file from multiple processes
diff --git a/netcdf/src/group.rs b/netcdf/src/group.rs
index 959c194..145d4a5 100644
--- a/netcdf/src/group.rs
+++ b/netcdf/src/group.rs
@@ -227,6 +227,7 @@ impl<'f> GroupMut<'f> {
         let (ncid, name) = super::group::get_parent_ncid_and_stem(self.id(), name)?;
         VariableMut::add_from_str(ncid, &T::type_descriptor(), name, dims)
     }
+
     /// Adds a variable from a set of unique identifiers, recursing upwards
     /// from the current group if necessary.
     pub fn add_variable_from_identifiers<'g, T>(
@@ -269,6 +270,20 @@ impl<'f> GroupMut<'f> {
         };
         super::variable::add_variable_from_identifiers(ncid, name, dims, xtype)
     }
+
+    /// Create a Variable containing strings into the dataset, with no data written into it
+    ///
+    /// Dimensions are identified using the name of the dimension, and will recurse upwards
+    /// if not found in the current group.
+    pub fn add_string_variable(
+        &mut self,
+        name: &str,
+        dims: &[&str],
+    ) -> error::Result<VariableMut<'f>> {
+        let typ = crate::types::NcVariableType::String;
+        let (ncid, name) = super::group::get_parent_ncid_and_stem(self.id(), name)?;
+        VariableMut::add_from_str(ncid, &typ, name, dims)
+    }
 }
 
 pub(crate) fn groups_at_ncid<'f>(ncid: nc_type) -> error::Result<impl Iterator<Item = Group<'f>>> {
diff --git a/netcdf/tests/types.rs b/netcdf/tests/types.rs
index 9f2c48b..3b019e4 100644
--- a/netcdf/tests/types.rs
+++ b/netcdf/tests/types.rs
@@ -483,3 +483,23 @@ fn no_subtype() {
     file.add_type::<Bar>().unwrap();
     file.add_type::<FooBar>().unwrap();
 }
+
+#[test]
+fn add_string_variable() {
+    let d = tempfile::tempdir().unwrap();
+    let path = d.path().join("stringy.nc");
+    {
+        let mut file = netcdf::create(path.clone()).unwrap();
+        file.add_string_variable("s", &[]).unwrap();
+
+        let mut group = file.add_group("g").unwrap();
+        group.add_string_variable("str", &[]).unwrap();
+    }
+    {
+        let file = netcdf::open(path).unwrap();
+        let var = file.variable("s").unwrap();
+        assert_eq!(var.vartype(), NcVariableType::String);
+        let var = file.variable("g/str").unwrap();
+        assert_eq!(var.vartype(), NcVariableType::String);
+    }
+}