Add page_main_container() and wrap layout_sidebar() contents

Author: gadenbuie

shiny/ui/_page.py

@@ -41,7 +41,7 @@
 from ._tag import consolidate_attrs
 from ._utils import get_window_title
 from .css import CssUnit, as_css_padding, as_css_unit
-from .fill._fill import as_fillable_container
+from .fill._fill import add_fill_classes, as_fillable_container
 
 page_sidebar_default: SidebarOpen = SidebarOpen(desktop="open", mobile="always")
 
@@ -128,7 +128,7 @@ def page_sidebar(
         navbar_title,
         layout_sidebar(
             sidebar,
-            *children,
+            page_main_container(*children),
             attrs,
             fillable=fillable,
             border=False,
@@ -143,6 +143,14 @@ def page_sidebar(
     )
 
 
+def page_main_container(*args: TagChild) -> Tag:
+    return add_fill_classes(
+        tags.main({"class": "bslib-page-main bslib-gap-spacing"}, *args),
+        fill_item=True,
+        fillable_container=True,
+    )
+
+
 @no_example()
 def page_navbar(
     *args: NavSetArg | MetadataNode | Sequence[MetadataNode],

shiny/ui/fill/_fill.py

@@ -215,3 +215,15 @@ def is_fill_item(tag: object) -> bool:
     # renders_to_tag_class(x, FILL_ITEM_CLASS, ".html-widget")
 
     return isinstance(tag, Tag) and tag.has_class(FILL_ITEM_CLASS)
+
+
+def add_fill_classes(
+    tag: Tag, fill_item: bool = True, fillable_container: bool = True
+) -> Tag:
+    if fill_item:
+        tag.add_class(FILL_ITEM_CLASS)
+    if fillable_container:
+        tag.add_class(FILL_CONTAINER_CLASS)
+    if fill_item or fillable_container:
+        tag.append(fill_dependency())
+    return tag