From 880bff9d2776b434377092bca64c65d8085d9dc5 Mon Sep 17 00:00:00 2001
From: Dongdong Tian <seisman.info@gmail.com>
Date: Wed, 11 Oct 2023 13:17:01 +0800
Subject: [PATCH] Update virtualfile_to_data as done in PR #2729

---
 pygmt/clib/session.py | 35 +++++++++++++++++++++++------------
 pygmt/datatypes.py    |  3 ++-
 pygmt/src/grdcut.py   | 11 +++++------
 3 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/pygmt/clib/session.py b/pygmt/clib/session.py
index c8d97fa459b..1dd04a42907 100644
--- a/pygmt/clib/session.py
+++ b/pygmt/clib/session.py
@@ -10,7 +10,6 @@
 import warnings
 from contextlib import contextmanager, nullcontext
 
-from pygmt.datatypes import GMT_GRID
 import numpy as np
 import pandas as pd
 from packaging.version import Version
@@ -22,6 +21,7 @@
     vectors_to_arrays,
 )
 from pygmt.clib.loading import load_libgmt
+from pygmt.datatypes import GMT_GRID
 from pygmt.exceptions import (
     GMTCLibError,
     GMTCLibNoSessionError,
@@ -1627,7 +1627,8 @@ def virtualfile_from_data(
 
     def read_virtualfile(self, vfname, kind=None):
         """
-        Read data from a virtual file and cast it into a GMT data container if requested.
+        Read data from a virtual file and cast it into a GMT data container if
+        requested.
 
         Parameters
         ----------
@@ -1665,27 +1666,37 @@ def read_virtualfile(self, vfname, kind=None):
         return ctp.cast(pointer, ctp.POINTER(type))
 
     @contextmanager
-    def virtualfile_to_data(self, kind):
+    def virtualfile_to_data(self, kind, fname=None):
         """
-        Create a virtual file for writing a GMT data container.
+        Create a virtual file for writing a GMT data container or yield the
+        output file name.
 
         Parameters
         ----------
         kind : str
             The kind of data container to create. Choose from "grid" or
-            "dataset".
+            "dataset". It has no effect if ``fname`` is given.
+
+        fname : str or None
+            If given, yield the output file name instead of the virtual file.
 
         Yields
         ------
         vfile : str
-            Name of the virtual file.
+            Name of the virtual file or the output file name.
         """
-        family, geometry = {
-            "grid": ("GMT_IS_GRID", "GMT_IS_SURFACE"),
-            "dataset": ("GMT_IS_DATASET", "GMT_IS_PLP"),
-        }[kind]
-        with self.open_virtual_file(family, geometry, "GMT_OUT", None) as vfile:
-            yield vfile
+        # If fname is given, yield the output file name.
+        if fname is not None:
+            yield fname
+        # Otherwise, create a virtual file for writing a GMT data container.
+        else:
+            # Determine the family and geometry of the data container based on 'kind'.
+            family, geometry = {
+                "grid": ("GMT_IS_GRID", "GMT_IS_SURFACE"),
+                "dataset": ("GMT_IS_DATASET", "GMT_IS_PLP"),
+            }[kind]
+            with self.open_virtual_file(family, geometry, "GMT_OUT", None) as vfile:
+                yield vfile
 
     @contextmanager
     def virtualfile_from_gmtgrid(self, grid_pointer):
diff --git a/pygmt/datatypes.py b/pygmt/datatypes.py
index 03af5d84db5..07e2d5308cc 100644
--- a/pygmt/datatypes.py
+++ b/pygmt/datatypes.py
@@ -33,7 +33,8 @@ class GMT_GRID_HEADER(ctp.Structure):
     """
     Structure for GMT grid header.
 
-    See https://docs.generic-mapping-tools.org/dev/devdocs/api.html#gmt-grid
+    See
+    https://docs.generic-mapping-tools.org/dev/devdocs/api.html#gmt-grid
     for definition.
     """
 
diff --git a/pygmt/src/grdcut.py b/pygmt/src/grdcut.py
index de0f8a36bdd..088d84d3510 100644
--- a/pygmt/src/grdcut.py
+++ b/pygmt/src/grdcut.py
@@ -100,15 +100,14 @@ def grdcut(grid, outgrid=None, **kwargs):
     with Session() as lib:
         with lib.virtualfile_from_data(
             check_kind="raster", data=grid
-        ) as infile, lib.virtualfile_to_data(kind="grid") as outfile:
-            kwargs["G"] = f"{outfile}"
+        ) as invfile, lib.virtualfile_to_data(kind="grid", fname=outgrid) as outvfile:
+            kwargs["G"] = f"{outvfile}"
             lib.call_module(
-                module="grdcut", args=build_arg_string(kwargs, infile=infile)
+                module="grdcut", args=build_arg_string(kwargs, infile=invfile)
             )
+
             # Output to a file or return an xarray.DataArray object
             if outgrid is not None:
-                lib.call_module("write", f"{outfile} {outgrid} -Tg")
                 return None
-
-            gmtgrid = lib.read_virtualfile_to_data(outfile, kind="grid")
+            gmtgrid = lib.read_virtualfile(outvfile, kind="grid")
             return gmtgrid.contents.to_dataarray()