Various small bug fixes, break out pagination for cards into its own mixin and templatetag

cards/mixins.py

@@ -0,0 +1,42 @@
+from math import ceil
+
+class ReusablePaginationMixin:
+    """
+    A mixin that encapsulates reusable pagination logic.
+    Use in Django ListViews to generate custom pagination context.
+    """
+    per_page = 10  # Default; can be overridden in your view.
+
+    def paginate_data(self, data_list, page_number):
+        """
+        Paginate a list of items.
+
+        Arguments:
+            data_list (list): The list of items to paginate.
+            page_number (int): Current page number.
+
+        Returns:
+            tuple: (paginated_items, pagination_context)
+        """
+        total_items = len(data_list)
+        num_pages = ceil(total_items / self.per_page) if self.per_page > 0 else 1
+
+        # Ensure page_number is within valid bounds.
+        if page_number < 1:
+            page_number = 1
+        elif page_number > num_pages:
+            page_number = num_pages
+
+        start = (page_number - 1) * self.per_page
+        end = page_number * self.per_page
+        items = data_list[start:end]
+
+        pagination_context = {
+            "number": page_number,
+            "has_previous": page_number > 1,
+            "has_next": page_number < num_pages,
+            "previous_page": page_number - 1 if page_number > 1 else 1,
+            "next_page": page_number + 1 if page_number < num_pages else num_pages,
+            "paginator": {"num_pages": num_pages},
+        }
+        return items, pagination_context