From 381514ab2cd9b42fd836fc704e70cbd8898e3878 Mon Sep 17 00:00:00 2001
From: Jan Lindemann <jan@janware.com>
Date: Thu, 16 Jan 2025 10:51:28 +0100
Subject: [PATCH] misc: Add load_class()

Add load_class() to complement load_object(), returning the class as
opposed to instantiated object.

Signed-off-by: Jan Lindemann <jan@janware.com>
---
 tools/python/jwutils/misc.py | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/tools/python/jwutils/misc.py b/tools/python/jwutils/misc.py
index 108f428..3b2ea05 100644
--- a/tools/python/jwutils/misc.py
+++ b/tools/python/jwutils/misc.py
@@ -4,7 +4,10 @@ import tempfile
 import filecmp
 import inspect
 import importlib
+import re
+
 from typing import Set, Iterable
+
 from jwutils import log
 
 _tmpfiles: Set[str] = set()
@@ -63,7 +66,7 @@ def get_derived_classes(mod, base, flt=None): # export
             log.slog(log.DEBUG, "  is not derived from", base, "only", inspect.getmro(c))
             continue
         if flt and not re.match(flt, name):
-            slog(DEBUG, '  "{}.{}" has wrong name'.format(mod, name))
+            log.slog(log.DEBUG, '  "{}.{}" has wrong name'.format(mod, name))
             continue
         r.append(c)
     return r
@@ -75,6 +78,15 @@ def load_classes(path, baseclass, flt=None): # export
         r.extend(get_derived_classes(mod, baseclass, flt))
     return r
 
+def load_class(module_path, baseclass, class_name_filter=None): # export
+    mod = importlib.import_module(module_path)
+    classes = get_derived_classes(mod, baseclass, flt=class_name_filter)
+    if len(classes) == 0:
+        raise Exception(f'no class matching "{class_name_filter}" of type "{baseclass}" found in module "{module_path}"')
+    if len(classes) > 1:
+        raise Exception(f'{len(classes)} classes matching "{class_name_filter}" of type "{baseclass}" found in module "{module_path}"')
+    return classes[0]
+
 def load_class_names(path, baseclass, flt=None, remove_flt=False): # export
     classes = load_classes(path, baseclass, flt)
     r = []
@@ -89,15 +101,8 @@ def load_class_names(path, baseclass, flt=None, remove_flt=False): # export
             #log.slog(log.WARNING, "{} is already in in {}".format(name, r))
     return r
 
-# TODO: handling of "name" / "flt" is awkward
-def load_object(path, baseclass, name = None, *args, **kwargs): # export
-    mod = importlib.import_module(path)
-    classes = get_derived_classes(mod, baseclass, flt=None)
-    if len(classes) == 0:
-        raise Exception("no class {} found".format(name))
-    if len(classes) > 1:
-        raise Exception("{} classes matching {} found".format(len(classes), name))
-    return classes[0](*args, **kwargs)
+def load_object(module_path, baseclass, class_name_filter=None, *args, **kwargs): # export
+    return load_class(module_path, baseclass, class_name_filter=class_name_filter)(*args, **kwargs)
 
 def commit_tmpfile(tmp: str, path: str) -> None: # export
     caller = log.get_caller_pos()