Fixes support for `classmethod` when defining a configclass (#901)

# Description

Previously, the configclass instance did not properly parse
classmethods. For instance, the following would fail:

```python
from __future__ import annotations

"""Launch Isaac Sim Simulator first."""

from omni.isaac.lab.app import AppLauncher

# launch omniverse app
app_launcher = AppLauncher(headless=True)

"""Rest everything follows."""

from omni.isaac.lab.utils.configclass import configclass


@configclass
class DummyClass:

    a: int = 5

    def instance_method(self):
        print("Value of a: ", self.a)

    @classmethod
    def class_method(cls, value: int) -> DummyClass:
        return cls(a=value)


cfg = DummyClass()

# check all methods are callable
cfg.instance_method()
new_cfg1 = cfg.class_method(20)

# create the same config instance using class method
new_cfg2 = DummyClass.class_method(20)
```

This MR fixes the checks to make sure class-methods remain bound to the
class and do not become instance variables.

## Type of change

- Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

source/extensions/omni.isaac.lab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.22.3"
+version = "0.22.4"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/extensions/omni.isaac.lab/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.22.4 (2024-08-29)
+~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Fixed the support for class-bounded methods when creating a configclass
+  out of them. Earlier, these methods were being made as instance methods
+  which required initialization of the class to call the class-methods.
+
+
 0.22.3 (2024-08-28)
 ~~~~~~~~~~~~~~~~~~~
 

source/extensions/omni.isaac.lab/omni/isaac/lab/utils/configclass.py

@@ -6,6 +6,7 @@
 """Sub-module that provides a wrapper around the Python 3.7 onwards ``dataclasses`` module."""
 
 import inspect
+import types
 from collections.abc import Callable
 from copy import deepcopy
 from dataclasses import MISSING, Field, dataclass, field, replace
@@ -392,6 +393,11 @@ def _skippable_class_member(key: str, value: Any, hints: dict | None = None) ->
         return True
     # skip functions bounded to class
     if callable(value):
+        # FIXME: This doesn't yet work for static methods because they are essentially seen as function types.
+        # check for class methods
+        if isinstance(value, types.MethodType):
+            return True
+        # check for instance methods
         signature = inspect.signature(value)
         if "self" in signature.parameters or "cls" in signature.parameters:
             return True

source/extensions/omni.isaac.lab/test/sensors/test_camera.py

@@ -249,7 +249,7 @@ class TestCamera(unittest.TestCase):
             prim_path="/World/Camera_2",
             update_period=0,
             data_types=["distance_to_image_plane"],
-            spawn=sim_utils.PinholeCameraCfg().from_intrinsic_matrix(
+            spawn=sim_utils.PinholeCameraCfg.from_intrinsic_matrix(
                 intrinsic_matrix=intrinsic_matrix,
                 width=128,
                 height=128,

source/extensions/omni.isaac.lab/test/sensors/test_ray_caster_camera.py

@@ -221,7 +221,7 @@ class TestWarpCamera(unittest.TestCase):
             update_period=0,
             offset=RayCasterCameraCfg.OffsetCfg(pos=(0.0, 0.0, 0.0), rot=(1.0, 0.0, 0.0, 0.0), convention="world"),
             debug_vis=False,
-            pattern_cfg=patterns.PinholeCameraPatternCfg().from_intrinsic_matrix(
+            pattern_cfg=patterns.PinholeCameraPatternCfg.from_intrinsic_matrix(
                 intrinsic_matrix=intrinsic_matrix,
                 height=self.camera_cfg.pattern_cfg.height,
                 width=self.camera_cfg.pattern_cfg.width,
@@ -665,7 +665,7 @@ class TestWarpCamera(unittest.TestCase):
             mesh_prim_paths=["/World/defaultGroundPlane"],
             offset=RayCasterCameraCfg.OffsetCfg(pos=offset_pos, rot=offset_rot, convention="ros"),
             debug_vis=False,
-            pattern_cfg=patterns.PinholeCameraPatternCfg().from_intrinsic_matrix(
+            pattern_cfg=patterns.PinholeCameraPatternCfg.from_intrinsic_matrix(
                 intrinsic_matrix=intrinsics,
                 height=540,
                 width=960,
@@ -677,7 +677,7 @@ class TestWarpCamera(unittest.TestCase):
         camera_usd_cfg = CameraCfg(
             prim_path="/World/Camera_usd",
             offset=CameraCfg.OffsetCfg(pos=offset_pos, rot=offset_rot, convention="ros"),
-            spawn=PinholeCameraCfg().from_intrinsic_matrix(
+            spawn=PinholeCameraCfg.from_intrinsic_matrix(
                 intrinsic_matrix=intrinsics,
                 height=540,
                 width=960,

source/extensions/omni.isaac.lab/test/sensors/test_tiled_camera.py

@@ -315,7 +315,7 @@ class TestTiledCamera(unittest.TestCase):
         camera_tiled_cfg = TiledCameraCfg(
             prim_path="/World/Camera_tiled",
             offset=TiledCameraCfg.OffsetCfg(pos=offset_pos, rot=offset_rot, convention="ros"),
-            spawn=sim_utils.PinholeCameraCfg().from_intrinsic_matrix(
+            spawn=sim_utils.PinholeCameraCfg.from_intrinsic_matrix(
                 intrinsic_matrix=intrinsics,
                 height=540,
                 width=960,
@@ -329,7 +329,7 @@ class TestTiledCamera(unittest.TestCase):
         camera_usd_cfg = CameraCfg(
             prim_path="/World/Camera_usd",
             offset=CameraCfg.OffsetCfg(pos=offset_pos, rot=offset_rot, convention="ros"),
-            spawn=sim_utils.PinholeCameraCfg().from_intrinsic_matrix(
+            spawn=sim_utils.PinholeCameraCfg.from_intrinsic_matrix(
                 intrinsic_matrix=intrinsics,
                 height=540,
                 width=960,

source/extensions/omni.isaac.lab/test/utils/test_configclass.py

@@ -3,6 +3,8 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
+from __future__ import annotations
+
 # NOTE: While we don't actually use the simulation app in this test, we still need to launch it
 #       because warp is only available in the context of a running simulation
 """Launch Isaac Sim Simulator first."""
@@ -292,6 +294,20 @@ class FunctionImplementedDemoCfg:
         self.a = a
 
 
+@configclass
+class ClassFunctionImplementedDemoCfg:
+    """Dummy configuration class with function members defined in the class."""
+
+    a: int = 5
+
+    def instance_method(self):
+        print("Value of a: ", self.a)
+
+    @classmethod
+    def class_method(cls, value: int) -> ClassFunctionImplementedDemoCfg:
+        return cls(a=value)
+
+
 """
 Dummy configuration: Nested dictionaries
 """
@@ -618,12 +634,31 @@ class TestConfigClass(unittest.TestCase):
         self.assertEqual(cfg.func_in_dict["func"](), 1)
 
     def test_function_impl_config(self):
+        """Tests having function defined in the class instance."""
         cfg = FunctionImplementedDemoCfg()
         # change value
         self.assertEqual(cfg.a, 5)
         cfg.set_a(10)
         self.assertEqual(cfg.a, 10)
 
+    def test_class_function_impl_config(self):
+        """Tests having class and static function defined in the class instance."""
+        cfg = ClassFunctionImplementedDemoCfg()
+
+        # check that the annotations are correct
+        self.assertDictEqual(cfg.__annotations__, {"a": "int"})
+
+        # check all methods are callable
+        cfg.instance_method()
+        new_cfg1 = cfg.class_method(20)
+        # check value is correct
+        self.assertEqual(new_cfg1.a, 20)
+
+        # create the same config instance using class method
+        new_cfg2 = ClassFunctionImplementedDemoCfg.class_method(20)
+        # check value is correct
+        self.assertEqual(new_cfg2.a, 20)
+
     def test_dict_conversion_functions_config(self):
         """Tests conversion of config with functions into dictionary."""
         cfg = FunctionsDemoCfg()