Prepare ad_creator() to handle plugin class names as text

CHANGES.rst

@@ -26,6 +26,16 @@ describe future plans.
 
    Release expected by 2024-12-31.
 
+   Enhancements
+   ------------
+
+   - Add 'dynamic_import()' (support 'ad_creator()' from device file).
+
+   Maintenance
+   -----------
+
+   - In 'ad_creator()', convert text class name to class object.
+
 1.7.1
 ******
 

apstools/devices/area_detector_factory.py

@@ -85,6 +85,7 @@
 import ophyd.areadetector.plugins
 from ophyd import ADComponent
 
+from ..utils import dynamic_import
 from .area_detector_support import AD_EpicsFileNameJPEGPlugin
 from .area_detector_support import AD_EpicsFileNameTIFFPlugin
 from .area_detector_support import HDF5FileWriterPlugin
@@ -324,6 +325,10 @@ def ad_class_factory(name, bases=None, plugins=None, plugin_defaults=None):
         if "suffix" not in kwargs:
             raise KeyError(f"Must define 'suffix': {kwargs}")
         component_class = kwargs.pop("class")
+        if isinstance(component_class, str):
+            # Convert text class into object, such as:
+            #    "apstools.devices.area_detector_support.SimDetectorCam_V34"
+            component_class = dynamic_import(component_class)
         suffix = kwargs.pop("suffix")
 
         # if "write_path_template" in defaults
@@ -374,7 +379,7 @@ def ad_creator(
         *object*:
         Plugin configuration dictionary.
         (default: ``None``, PLUGIN_DEFAULTS will be used.)
-    kwargs 
+    kwargs
         *dict*:
         Any additional keyword arguments for the new class definition.
         (default: ``{}``)

apstools/utils/__init__.py

@@ -59,6 +59,7 @@
 from .misc import count_child_devices_and_signals
 from .misc import count_common_subdirs
 from .misc import dictionary_table
+from .misc import dynamic_import
 from .misc import full_dotted_name
 from .misc import itemizer
 from .misc import listobjects

apstools/utils/misc.py

@@ -10,6 +10,7 @@
    ~count_child_devices_and_signals
    ~count_common_subdirs
    ~dictionary_table
+   ~dynamic_import
    ~full_dotted_name
    ~itemizer
    ~listobjects
@@ -92,20 +93,22 @@ def wrapper(*a, **kw):
     return wrapper
 
 
-def cleanupText(text):
+def cleanupText(text, replace="_"):
     """
-    convert text so it can be used as a dictionary key
+    Convert text so it can be used as a dictionary key.
 
     Given some input text string, return a clean version
     remove troublesome characters, perhaps other cleanup as well.
     This is best done with regular expression pattern matching.
     """
     pattern = "[a-zA-Z0-9_]"
+    if replace is None:
+        replace = "_"
 
     def mapper(c):
         if re.match(pattern, c) is not None:
             return c
-        return "_"
+        return replace
 
     return "".join([mapper(c) for c in text])
 
@@ -192,6 +195,48 @@ def dictionary_table(dictionary, **kwargs):
     return t
 
 
+def dynamic_import(full_path: str) -> type:
+    """
+    Import the object given its import path as text.
+
+    Motivated by specification of class names for plugins
+    when using ``apstools.devices.ad_creator()``.
+
+    EXAMPLES::
+
+        obj = dynamic_import("ophyd.EpicsMotor")
+        m1 = obj("gp:m1", name="m1")
+
+        IocStats = dynamic_import("instrument.devices.ioc_stats.IocInfoDevice")
+        gp_stats = IocStats("gp:", name="gp_stats")
+    """
+    from importlib import import_module
+
+    import_object = None
+
+    if "." not in full_path:
+        # fmt: off
+        raise ValueError(
+            "Must use a dotted path, no local imports."
+            f" Received: {full_path!r}"
+        )
+        # fmt: on
+
+    if full_path.startswith("."):
+        # fmt: off
+        raise ValueError(
+            "Must use absolute path, no relative imports."
+            f" Received: {full_path!r}"
+        )
+        # fmt: on
+
+    module_name, object_name = full_path.rsplit(".", 1)
+    module_object = import_module(module_name)
+    import_object = getattr(module_object, object_name)
+
+    return import_object
+
+
 def full_dotted_name(obj):
     """
     Return the full dotted name

apstools/utils/tests/test_misc.py

@@ -0,0 +1,54 @@
+"""Test parts of the utils.misc module."""
+
+import ophyd
+import pytest
+
+from .._core import MAX_EPICS_STRINGOUT_LENGTH
+from ..misc import cleanupText
+from ..misc import dynamic_import
+
+
+class CustomClass:
+    """some local class"""
+
+
+@pytest.mark.parametrize(
+    "original, expected, replacement",
+    [
+        ["abcd12345", "abcd12345", None],
+        ["aBcd12345", "aBcd12345", None],
+        ["abcd 12345", "abcd_12345", None],
+        ["abcd-12345", "abcd_12345", None],
+        ["  abc  ", "__abc__", None],
+        ["  abc  ", "__abc__", None],
+        ["  abc  ", "__abc__", "_"],
+        ["  abc  ", "..abc..", "."],
+    ],
+)
+def test_cleaupText(original, expected, replacement):
+    result = cleanupText(original, replace=replacement)
+    assert result == expected, f"{original=!r}  {result=!r}  {expected=!r}"
+
+
+@pytest.mark.parametrize(
+    "specified, expected, error",
+    [
+        ["ophyd.EpicsMotor", ophyd.EpicsMotor, None],
+        ["apstools.utils.dynamic_import", dynamic_import, None],
+        ["apstools.utils.misc.cleanupText", cleanupText, None],
+        [
+            "apstools.utils._core.MAX_EPICS_STRINGOUT_LENGTH",
+            MAX_EPICS_STRINGOUT_LENGTH,
+            None,
+        ],
+        ["CustomClass", None, ValueError],
+        [".test_utils.CATALOG", None, ValueError],
+    ],
+)
+def test_dynamic_import(specified, expected, error):
+    if error is None:
+        obj = dynamic_import(specified)
+        assert obj == expected, f"{specified=!r}  {obj=}  {expected=}"
+    else:
+        with pytest.raises(error):
+            obj = dynamic_import(specified)

docs/source/api/_utils.rst

@@ -80,6 +80,7 @@ Other Utilities
    ~apstools.utils.apsu_controls_subnet.warn_if_not_aps_controls_subnet
    ~apstools.utils.misc.cleanupText
    ~apstools.utils.misc.connect_pvlist
+   ~apstools.utils.misc.dynamic_import
    ~apstools.utils.email.EmailNotifications
    ~apstools.utils.plot.select_live_plot
    ~apstools.utils.plot.select_mpl_figure
@@ -103,6 +104,7 @@ General
    ~apstools.utils.catalog.copy_filtered_catalog
    ~apstools.utils.query.db_query
    ~apstools.utils.misc.dictionary_table
+   ~apstools.utils.misc.dynamic_import
    ~apstools.utils.email.EmailNotifications
    ~apstools.utils.spreadsheet.ExcelDatabaseFileBase
    ~apstools.utils.spreadsheet.ExcelDatabaseFileGeneric