Add function to refresh task count in tags

GTG/core/datastore.py

@@ -28,7 +28,7 @@
 import string
 
 from GTG.core.tasks import TaskStore, Filter
-from GTG.core.tags import TagStore
+from GTG.core.tags import TagStore, Tag
 from GTG.core.saved_searches import SavedSearchStore
 from GTG.core import firstrun_tasks
 from GTG.core.dates import Date
@@ -193,6 +193,25 @@ def print_info(self) -> None:
         print(f'- Tasks: {self.tasks.count()}')
 
 
+    def refresh_task_for_tag(self, tag: Tag) -> None:
+        """Refresh task counts for a tag."""
+
+        try:
+            tag.task_count_open = self.task_count['open'][tag.name]
+        except KeyError:
+            tag.task_count_open = 0
+
+        try:
+            tag.task_count_closed = self.task_count['closed'][tag.name]
+        except KeyError:
+            tag.task_count_closed = 0
+
+        try:
+            tag.task_count_actionable = self.task_count['actionable'][tag.name]
+        except KeyError:
+            tag.task_count_actionable = 0
+
+
     def refresh_task_count(self) -> None:
         """Refresh task count dictionary."""