Add save/load_attribute helper

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 # Unreleased
 
+- Adds save/load_attribute helper
 - Adds `@cachable` decorator utility
 
 # v4.10.2

src/machinable/element.py

@@ -30,6 +30,7 @@
 from machinable.utils import (
     Jsonable,
     id_from_uuid,
+    joinpath,
     norm_version_call,
     sentinel,
     serialize,
@@ -292,6 +293,7 @@ def __init__(self, version: VersionType = None):
         self._config: Optional[DictConfig] = None
         self._predicate: Optional[DictConfig] = None
         self._context: Optional[DictConfig] = None
+        self._attributes = {}
         self._cache = {}
         self._kwargs = {}
 
@@ -654,6 +656,22 @@ def serialize(self) -> Dict:
         self.__model__.predicate = self.compute_predicate()
         return self.__model__.model_dump()
 
+    def save_attribute(self, name: Union[str, List[str]], data: Any) -> str:
+        name = joinpath(name)
+
+        self._attributes[name] = data
+
+        return name
+
+    def load_attribute(
+        self, name: Union[str, List[str]], default=None
+    ) -> Optional[Any]:
+        name = joinpath(name)
+
+        data = self._attributes.get(name, None)
+
+        return data if data is not None else default
+
     @classmethod
     def unserialize(cls, serialized):
         return cls.from_model(cls.model()(**serialized))

tests/test_element.py

@@ -482,3 +482,18 @@ class T(Connectable):
             assert Dummy.get() is dummy_1
         assert Dummy.get() is not dummy_1
         assert not Dummy.is_connected()
+
+
+def test_element_attributes():
+    t = Element()
+
+    assert t.load_attribute("test") is None
+    assert t.save_attribute("test", None) == "test"
+    assert t.load_attribute("test") is None
+    t.save_attribute("test", "hello")
+    assert t.load_attribute("test") == "hello"
+    assert t.save_attribute(["test", "me"], True) == "test/me"
+    assert t.load_attribute("test/me")
+
+    t = Element()
+    assert t.load_attribute("test") is None