fix: dont use query for children total count

lektor_groupby/pagination.py

@@ -1,20 +1,29 @@
 from lektor import datamodel
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Dict
 if TYPE_CHECKING:
+    from lektor.environment import Environment
     from lektor.pagination import Pagination
     from lektor.sourceobj import SourceObject
 
 
 class PaginationConfig(datamodel.PaginationConfig):
     # because original method does not work for virtual sources.
+    def __init__(self, env: 'Environment', config: Dict[str, Any], total: int):
+        super().__init__(env, **config)
+        self._total_items_count = total
+
     @staticmethod
-    def get_record_for_page(source: 'SourceObject', page_num: int) -> Any:
-        for_page = getattr(source, '__for_page__', None)
+    def get_record_for_page(record: 'SourceObject', page_num: int) -> Any:
+        for_page = getattr(record, '__for_page__', None)
         if callable(for_page):
             return for_page(page_num)
-        return datamodel.PaginationConfig.get_record_for_page(source, page_num)
+        return datamodel.PaginationConfig.get_record_for_page(record, page_num)
+
+    def count_total_items(self, record: 'SourceObject') -> int:
+        ''' Override super() to prevent a record.children query. '''
+        return self._total_items_count
 
     if TYPE_CHECKING:
-        def get_pagination_controller(self, source: 'SourceObject') \
+        def get_pagination_controller(self, record: 'SourceObject') \
                 -> 'Pagination':
             ...