dash 4.5.0rc2

Dash Version 4.5.0rc2

on Python PyPI

Removed

• #4039 Remove unnecessary Python version checks (pre 3.9).

Changed

• #4073 Move plotly-cloud back to the optional dash[cloud] extra (it was a default dependency in 4.5.0rc0/rc1), since it is not available on conda-forge.

Fixed

• #4075 fastapi backend: run before_request hooks on every route of the Dash app (assets, hook routes, api_endpoint, pages, when mounted) and send a non-None hook result as the response, as on Flask. fastapi and quart also run them on the WebSocket handshake.
• #4075 Background callbacks without cache_by no longer share a result between requests with equal inputs (unread Diskcache results now expire after a day, or after expire when set, even with cache_by), and callbacks with the same source no longer share a cache key. build_cache_key takes a new callback_key argument.
• #4075 dcc.Location(refresh=True).href, html.Area.href and html.Base.href now block javascript: URLs like html.A.
• #4075 Pages path_template matching no longer errors or backtracks badly on paths with a newline.
• #4075 Add configure_mcp_server(cache_by=..., cache_maxsize=...) so apps whose layout or callbacks depend on the user can keep the MCP server's cached tool descriptions and initial values per user (128 users by default, None for no limit).
• #4052 Fix callbacks of removed components still firing after a callback returns None for children: the renderer now clears their paths. Fixes #4033.

Updated

• npm packages: dash-renderer 3.5.2, dash-core-components / dash-html-components 4.5.2, dash-table 7.5.2.
• Dependency and CI updates (#4072, #4079).