Fix page number issue when changing page size (#782)

Co-authored-by: Amin Alaee <[email protected]>

sqladmin/pagination.py

@@ -46,6 +46,11 @@ def next_page(self) -> PageControl:
 
         raise RuntimeError("Next page not found.")
 
+    def resize(self, page_size: int) -> Pagination:
+        self.page = (self.page - 1) * self.page_size // page_size + 1
+        self.page_size = page_size
+        return self
+
     def add_pagination_urls(self, base_url: URL) -> None:
         # Previous pages
         for p in range(self.page - min(self.max_page_controls, 3), self.page):

sqladmin/templates/sqladmin/list.html

@@ -198,7 +198,7 @@ <h3 class="card-title">{{ model_view.name_plural }}</h3>
         </a>
         <div class="dropdown-menu">
           {% for page_size_option in model_view.page_size_options %}
-          <a class="dropdown-item" href="{{ request.url.include_query_params(pageSize=page_size_option) }}">
+          <a class="dropdown-item" href="{{ request.url.include_query_params(pageSize=page_size_option, page=pagination.resize(page_size_option).page) }}">
             {{ page_size_option }} / Page
           </a>
           {% endfor %}

tests/test_pagination.py

@@ -72,3 +72,14 @@ def test_multi_page_unequal_previous_and_next() -> None:
     ]
 
     assert pagination.page_controls == page_controls
+
+
+def test_resize_pagination() -> None:
+    pagination = Pagination(rows=[], page=3, page_size=5, count=20)
+    assert pagination.resize(100).page == 1
+
+    pagination = Pagination(rows=[], page=3, page_size=5, count=20)
+    assert pagination.resize(1).page == 11
+
+    pagination = Pagination(rows=[], page=3, page_size=5, count=20)
+    assert pagination.resize(8).page == 2