docs: add info about how to use getter data into pager widgets

docs/faq.rst

@@ -76,4 +76,24 @@ How can I pass data between dialogs?
 Input - pass via ``dialog_manager.start(..., data="here")``, read using ``dialog_manager.start_data``.
 Output - pass via ``dialog_manager.done(result="here")``, read as a parameter to ``on_process_result`` of parent dialog
 
-More details: :ref:`start-dialog`, :ref:`close-dialog`.
+More details: :ref:`start-dialog`, :ref:`close-dialog`.
+
+
+How can I can use "when" condition in pager widget?
+========================================================
+
+Pager widgets like ListGroup, PrevPage, NextPage, etc. use separate data, unlike other widgets like Button, Select.
+To use pass some information from the original data, which our getter returns - you need to use magic_filter to first access data and then the key of the desired data.
+For example
+
+.. code-block:: python
+    from aiogram_dialog.widgets.kbd import NextPage
+    from aiogram_dialog.widgets.text import Const
+    from magic_filter import F
+
+
+    next_page = NextPage(
+            text=Const("Next page"),
+            scroll="some_scroll",
+            when=F["data"]["show_next_page"],
+        )

example/scrolls.py

@@ -9,6 +9,7 @@
 from aiogram.fsm.state import State, StatesGroup
 from aiogram.fsm.storage.memory import MemoryStorage
 from aiogram.types import Message
+from magic_filter import F
 
 from aiogram_dialog import (
     Dialog,
@@ -76,6 +77,8 @@ class DialogSG(StatesGroup):
 async def product_getter(**_kwargs):
     return {
         "products": [(f"Product {i}", i) for i in range(1, 30)],
+        "show_hidden_prev_page": False,
+        "show_hidden_next_page": False,
     }
 
 
@@ -126,7 +129,7 @@ async def paging_getter(dialog_manager: DialogManager, **_kwargs):
         Const("Scrolling group with external paging controls"),
         NumberedPager(
             scroll="scroll_no_pager",
-            page_text=Format("{target_page1}\uFE0F\u20E3"),
+            page_text=Format("{target_page1}\ufe0f\u20e3"),
             current_page_text=Format("{current_page1}"),
         ),
         NumberedPager(
@@ -146,21 +149,38 @@ async def paging_getter(dialog_manager: DialogManager, **_kwargs):
             id="scroll_no_pager",
         ),
         Row(
-
             FirstPage(
-                scroll="scroll_no_pager", text=Format("⏮️ {target_page1}"),
+                scroll="scroll_no_pager",
+                text=Format("⏮️ {target_page1}"),
             ),
             PrevPage(
-                scroll="scroll_no_pager", text=Format("◀️"),
+                scroll="scroll_no_pager",
+                text=Format("◀️"),
             ),
             CurrentPage(
-                scroll="scroll_no_pager", text=Format("{current_page1}"),
+                scroll="scroll_no_pager",
+                text=Format("{current_page1}"),
             ),
             NextPage(
-                scroll="scroll_no_pager", text=Format("▶️"),
+                scroll="scroll_no_pager",
+                text=Format("▶️"),
             ),
             LastPage(
-                scroll="scroll_no_pager", text=Format("{target_page1} ⏭️"),
+                scroll="scroll_no_pager",
+                text=Format("{target_page1} ⏭️"),
+            ),
+        ),
+        # example of using data from getter in pager widgets
+        Row(
+            PrevPage(
+                text=Const("Hidden prev page"),
+                scroll="scroll_no_pager",
+                when=F["data"]["show_hidden_prev_page"],
+            ),
+            NextPage(
+                text=Const("Hidden next page"),
+                scroll="scroll_no_pager",
+                when=F["data"]["show_hidden_next_page"],
             ),
         ),
         Row(