allow SIGNOFFS_SIGNET_DEFAULTS to be a dotted import path for lazy ev…

…aluation

signoffs/core/models/signets.py

@@ -20,6 +20,7 @@
 from django.utils import timezone
 
 from signoffs import settings
+from signoffs.core.utils import dynamic_import
 
 
 class SignetQuerySet(models.QuerySet):
@@ -218,13 +219,14 @@ def update(self, defaults=False, **attrs):
     def get_signet_defaults(self):
         """Return dict of default field values for this signet - signet MUST have user relation!"""
         defaults = settings.SIGNOFFS_SIGNET_DEFAULTS
+        defaults = dynamic_import(defaults) if isinstance(defaults, str) else defaults
         return (
             get_signet_defaults(self)
             if defaults is None
             else defaults(self)
             if callable(defaults)
-            else defaults
-        )  # otherwise, defaults must be a dict-like object
+            else defaults  # otherwise, defaults must be a dict-like object
+        )
 
     def set_signet_defaults(self):
         """Set default field values for this signet - signet MUST have user relation!"""

signoffs/core/tests/test_utils.py

@@ -33,6 +33,12 @@ def test_id_to_camel(self):
         self.assertEqual(utils.id_to_camel("snake_snake_case"), "SnakeSnakeCase")
         self.assertEqual(utils.id_to_camel("dot.separated-id"), "DotSeparatedId")
 
+    def test_dynamic_import(self):
+        f = utils.dynamic_import("signoffs.core.utils.dynamic_import")
+        self.assertEqual(f, utils.dynamic_import)
+        f = utils.dynamic_import("signoffs.core.utils", "service")
+        self.assertEqual(f, utils.service)
+
 
 data = SimpleNamespace(
     obj1=SimpleNamespace(

signoffs/core/utils.py

@@ -2,6 +2,7 @@
 Utility functions and classes
 """
 import re
+from importlib import import_module
 
 from django.core.exceptions import FieldDoesNotExist
 
@@ -22,6 +23,21 @@ def id_to_camel(name):
     return "".join(el[:1].capitalize() + el[1:] for el in re.split(id_separators, name))
 
 
+def dynamic_import(abs_module_path, obj_name=None):
+    """
+    Dynamically import the given object (class, function, constant, etc.) from the given module_path
+    If obj_name is None, the last dotted item in the module_path will be imported
+    """
+    if not obj_name:
+        abs_module_path, obj_name = abs_module_path.rsplit(".", 1)
+
+    module_object = import_module(abs_module_path)
+
+    target_obj = getattr(module_object, obj_name)
+
+    return target_obj
+
+
 class Accessor(str):
     """
     A string describing a path from one object to another via attributes accesses.
@@ -263,6 +279,7 @@ def class_service(service_class, **kwargs):
 
 
 __all__ = [
+    "dynamic_import",
     "service",
     "ServiceDescriptor",
     "class_service",

signoffs/settings.py

@@ -8,7 +8,8 @@
     settings, "SIGNOFFS_AUTODISCOVER_MODULE", "signoffs"
 )
 
-# dictionary or callable(signet) that returns default values for mutable signet fields.
+# dictionary, or callable(signet) that returns one, or a string with dotted import path to either
+# A dict that provides default values for mutable signet fields.
 SIGNOFFS_SIGNET_DEFAULTS = getattr(settings, "SIGNOFFS_SIGNET_DEFAULTS", None)
 
 # SIGNOFFS_SETTING = getattr(settings, 'SIGNOFFS_SETTING', 'DEFAULT')

signoffs/templatetags/signoff_tags.py

@@ -11,6 +11,7 @@ def can_sign(signoff_or_approval_instance, user):
     """Returns True if the signoff_or_approval_instance can be signed by the given user (in theory)"""
     return signoff_or_approval_instance.can_sign(user)
 
+
 @register.filter
 def can_revoke(signoff_or_approval_instance, user):
     """Returns True if the signoff_or_approval_instance can be revoked by the given user (in theory)"""