From e4d5abc63b10210db074e71a2979308d74ca8e41 Mon Sep 17 00:00:00 2001
From: Dan Mahr <danmahr23@gmail.com>
Date: Mon, 10 Apr 2023 20:28:05 -0400
Subject: [PATCH] ENH: Added `allow_superseded` kwargs to `TransformerGroup`
 (#1269)

---
 docs/history.rst         |  1 +
 pyproj/_transformer.pyi  |  1 +
 pyproj/_transformer.pyx  |  6 ++++++
 pyproj/proj.pxi          |  5 +++++
 pyproj/transformer.py    |  7 +++++++
 test/test_transformer.py | 17 +++++++++++++++++
 6 files changed, 37 insertions(+)

diff --git a/docs/history.rst b/docs/history.rst
index 522290c00..4ea3d7c6b 100644
--- a/docs/history.rst
+++ b/docs/history.rst
@@ -3,6 +3,7 @@ Change Log
 
 Latest
 ------
+- ENH: Added allow_superseded kwargs to :class:`pyproj.transformer.TransformerGroup` (pull #1269)
 
 - ENH: Added :meth:`CRS.to_2d` to demote 3D CRS to 2D (issue #1266)
 
diff --git a/pyproj/_transformer.pyi b/pyproj/_transformer.pyi
index 37de4eb6f..0908829fd 100644
--- a/pyproj/_transformer.pyi
+++ b/pyproj/_transformer.pyi
@@ -41,6 +41,7 @@ class _TransformerGroup:
         authority: Optional[str],
         accuracy: Optional[float],
         allow_ballpark: bool,
+        allow_superseded: bool,
     ) -> None: ...
 
 class _Transformer(Base):
diff --git a/pyproj/_transformer.pyx b/pyproj/_transformer.pyx
index 7bc6f3886..13491e08e 100644
--- a/pyproj/_transformer.pyx
+++ b/pyproj/_transformer.pyx
@@ -141,6 +141,7 @@ cdef class _TransformerGroup:
         bint allow_ballpark,
         str authority,
         double accuracy,
+        bint allow_superseded,
     ):
         """
         From PROJ docs:
@@ -202,6 +203,11 @@ cdef class _TransformerGroup:
                 operation_factory_context,
                 allow_ballpark,
             )
+            proj_operation_factory_context_set_discard_superseded(
+                self.context,
+                operation_factory_context,
+                not allow_superseded,
+            )
             proj_operation_factory_context_set_grid_availability_use(
                 self.context,
                 operation_factory_context,
diff --git a/pyproj/proj.pxi b/pyproj/proj.pxi
index a28d5e6c6..96bab8c48 100644
--- a/pyproj/proj.pxi
+++ b/pyproj/proj.pxi
@@ -478,6 +478,11 @@ cdef extern from "proj.h" nogil:
         PJ_OPERATION_FACTORY_CONTEXT *factory_ctx,
         int allow
     )
+    void proj_operation_factory_context_set_discard_superseded(
+        PJ_CONTEXT *ctx,
+        PJ_OPERATION_FACTORY_CONTEXT *factory_ctx,
+        int discard
+    )
     void proj_operation_factory_context_set_desired_accuracy(
         PJ_CONTEXT *ctx,
         PJ_OPERATION_FACTORY_CONTEXT *factory_ctx,
diff --git a/pyproj/transformer.py b/pyproj/transformer.py
index c088e2220..a827294b1 100644
--- a/pyproj/transformer.py
+++ b/pyproj/transformer.py
@@ -161,11 +161,13 @@ def __init__(
         authority: Optional[str] = None,
         accuracy: Optional[float] = None,
         allow_ballpark: bool = True,
+        allow_superseded: bool = False,
     ) -> None:
         """Get all possible transformations from a :obj:`pyproj.crs.CRS`
         or input used to create one.
 
         .. versionadded:: 3.4.0 authority, accuracy, allow_ballpark
+        .. versionadded:: 3.6.0 allow_superseded
 
         Parameters
         ----------
@@ -195,6 +197,10 @@ def __init__(
         allow_ballpark: bool, default=True
             Set to False to disallow the use of Ballpark transformation
             in the candidate coordinate operations. Default is to allow.
+        allow_superseded: bool, default=False
+            Set to True to allow the use of superseded (but not deprecated)
+            transformations in the candidate coordinate operations. Default is
+            to disallow.
 
         """
         super().__init__(
@@ -205,6 +211,7 @@ def __init__(
             authority=authority,
             accuracy=-1 if accuracy is None else accuracy,
             allow_ballpark=allow_ballpark,
+            allow_superseded=allow_superseded,
         )
         for iii, transformer in enumerate(self._transformers):
             # pylint: disable=unsupported-assignment-operation
diff --git a/test/test_transformer.py b/test/test_transformer.py
index c18ba1d25..55a436963 100644
--- a/test/test_transformer.py
+++ b/test/test_transformer.py
@@ -1651,6 +1651,23 @@ def test_transformer_group_allow_ballpark_filter():
     assert not group.unavailable_operations
 
 
+@pytest.mark.parametrize(
+    "from_crs, to_crs, allow_superseded, expected_num_transformers",
+    [
+        (6319, 5703, 0, 2),
+        (6319, 5703, False, 2),
+        (6319, 5703, True, 3),
+        (6319, 5703, 123456789, 3),
+        (6319, 5703, "blah", 3),
+    ],
+)
+def test_transformer_group_allow_superseded_filter(
+    from_crs, to_crs, allow_superseded, expected_num_transformers
+):
+    group = TransformerGroup(from_crs, to_crs, allow_superseded=allow_superseded)
+    assert len(group.transformers) == expected_num_transformers
+
+
 def test_transformer_group_authority_filter():
     group = TransformerGroup("EPSG:4326", "EPSG:4258", authority="PROJ")
     assert len(group.transformers) == 1