refactor: simplify repository factory with Django-style import_string (#24354)

api/libs/module_loading.py

@@ -0,0 +1,55 @@
+"""
+Module loading utilities similar to Django's module_loading.
+
+Reference implementation from Django:
+https://github.com/django/django/blob/main/django/utils/module_loading.py
+"""
+
+import sys
+from importlib import import_module
+from typing import Any
+
+
+def cached_import(module_path: str, class_name: str) -> Any:
+    """
+    Import a module and return the named attribute/class from it, with caching.
+
+    Args:
+        module_path: The module path to import from
+        class_name: The attribute/class name to retrieve
+
+    Returns:
+        The imported attribute/class
+    """
+    if not (
+        (module := sys.modules.get(module_path))
+        and (spec := getattr(module, "__spec__", None))
+        and getattr(spec, "_initializing", False) is False
+    ):
+        module = import_module(module_path)
+    return getattr(module, class_name)
+
+
+def import_string(dotted_path: str) -> Any:
+    """
+    Import a dotted module path and return the attribute/class designated by
+    the last name in the path. Raise ImportError if the import failed.
+
+    Args:
+        dotted_path: Full module path to the class (e.g., 'module.submodule.ClassName')
+
+    Returns:
+        The imported class or attribute
+
+    Raises:
+        ImportError: If the module or attribute cannot be imported
+    """
+    try:
+        module_path, class_name = dotted_path.rsplit(".", 1)
+    except ValueError as err:
+        raise ImportError(f"{dotted_path} doesn't look like a module path") from err
+
+    try:
+        return cached_import(module_path, class_name)
+    except AttributeError as err:
+        raise ImportError(f'Module "{module_path}" does not define a "{class_name}" attribute/class') from err