Minor refactoring.

[plomtask] / plomtask / versioned_attributes.py

diff --git a/plomtask/versioned_attributes.py b/plomtask/versioned_attributes.py
index cc42bbc40f761c35715f11b0ca4f61ba67dbe579..cfcbf87f2c79de1c21f85169b0e29db8d30e6b70 100644 (file)
--- a/plomtask/versioned_attributes.py
+++ b/plomtask/versioned_attributes.py
@@ -4,7 +4,8 @@ from typing import Any
 from sqlite3 import Row
 from time import sleep
 from plomtask.db import DatabaseConnection
-from plomtask.exceptions import HandledException, BadFormatException
+from plomtask.exceptions import (HandledException, BadFormatException,
+                                 NotFoundException)
 
 TIMESTAMP_FMT = '%Y-%m-%d %H:%M:%S.%f'
 
@@ -16,31 +17,30 @@ class VersionedAttribute:
                  parent: Any, table_name: str, default: str | float) -> None:
         self.parent = parent
         self.table_name = table_name
-        self.default = default
+        self._default = default
         self.history: dict[str, str | float] = {}
 
     def __hash__(self) -> int:
         history_tuples = tuple((k, v) for k, v in self.history.items())
-        hashable = (self.parent.id_, self.table_name, self.default,
+        hashable = (self.parent.id_, self.table_name, self._default,
                     history_tuples)
         return hash(hashable)
 
-    @property
-    def as_dict(self) -> dict[str, object]:
-        """Return self as (json.dumps-coompatible) dict."""
-        d = {'parent_id': self.parent.id_, 'history': self.history}
-        return d
-
     @property
     def _newest_timestamp(self) -> str:
         """Return most recent timestamp."""
         return sorted(self.history.keys())[-1]
 
+    @property
+    def value_type_name(self) -> str:
+        """Return string of name of attribute value type."""
+        return type(self._default).__name__
+
     @property
     def newest(self) -> str | float:
-        """Return most recent value, or self.default if self.history empty."""
+        """Return most recent value, or self._default if self.history empty."""
         if 0 == len(self.history):
-            return self.default
+            return self._default
         return self.history[self._newest_timestamp]
 
     def reset_timestamp(self, old_str: str, new_str: str) -> None:
@@ -94,7 +94,7 @@ class VersionedAttribute:
             queried_time += ' 23:59:59.999'
         sorted_timestamps = sorted(self.history.keys())
         if 0 == len(sorted_timestamps):
-            return self.default
+            return self._default
         selected_timestamp = sorted_timestamps[0]
         for timestamp in sorted_timestamps[1:]:
             if timestamp > queried_time:
@@ -104,6 +104,8 @@ class VersionedAttribute:
 
     def save(self, db_conn: DatabaseConnection) -> None:
         """Save as self.history entries, but first wipe old ones."""
+        if self.parent.id_ is None:
+            raise NotFoundException('cannot save attribute to parent if no ID')
         db_conn.rewrite_relations(self.table_name, 'parent', self.parent.id_,
                                   [[item[0], item[1]]
                                    for item in self.history.items()])