FletStaticFiles

Serve Flet app static files.

Text and WebAssembly files, like the web client's main.dart.wasm and main.dart.js, are sent gzip-compressed to browsers that accept it, which makes them about 3x smaller to download. Each file is compressed once, in a worker thread, on its first request, and the compressed copy is kept in a temporary directory until the server exits. Byte range requests get the uncompressed file.

Parameters:

• assets_dir (str | None, default: None) - Path to app's assets directory. A relative path is resolved against the current working directory.
• app_name (str | None, default: None) - PWA application name.
• app_short_name (str | None, default: None) - PWA application short name.
• app_description (str | None, default: None) - PWA application description.
• web_renderer (WebRenderer, default: WebRenderer.AUTO) - Type of web renderer, as a WebRenderer or its value, e.g. "canvaskit".
• route_url_strategy (RouteUrlStrategy, default: RouteUrlStrategy.PATH) - Routing URL strategy, as a RouteUrlStrategy or its value, e.g. "hash".
• no_cdn (bool, default: False) - Whether not load CanvasKit, Pyodide, and fonts from CDN.
• websocket_endpoint_path (str | None, default: None) - Path of Flet app WebSocket handler. A path without a leading / is resolved against the app mount path. Defaults to ws.

Inherits: fastapi.staticfiles.StaticFiles

Properties

• font_manifest_json
• index
• manifest_json
• route_url_strategy - The route URL strategy written into the served index.html: the route_url_strategy argument, or FLET_WEB_ROUTE_URL_STRATEGY if set.

Methods

• file_response - Respond with a static file, adding Vary: Accept-Encoding to compressible ones.
• get_response - Respond with a static file, gzip-compressed if the browser accepts it.
• is_not_modified - Whether the browser's cached copy of a file is still current.
• lookup_path - Resolve a static file path, with SPA fallback for client-side routes.

Properties

buildfont_manifest_jsoninstance-attribute

buildindexinstance-attribute

buildmanifest_jsoninstance-attribute

buildroute_url_strategyproperty

route_url_strategy: RouteUrlStrategy

The route URL strategy written into the served index.html: the route_url_strategy argument, or FLET_WEB_ROUTE_URL_STRATEGY if set.

Methods

deployed_codefile_response

file_response(
    full_path: str | os.PathLike[str],
    stat_result: os.stat_result,
    scope: Scope,
    status_code: int = 200,
) -> Response

Respond with a static file, adding Vary: Accept-Encoding to compressible ones.

Unlike StaticFiles, this never responds with 304 Not Modified: get_response() checks the browser's cached copy once it has picked the plain or compressed file.

deployed_codeget_responseasync

get_response(path: str, scope: Scope) -> Response

Respond with a static file, gzip-compressed if the browser accepts it.

Parameters:

• path (str) - Requested path, relative to the mounted static root.
• scope (Scope) - ASGI request scope.

Returns:

• Response - The compressed file for a 200 response of a compressible file to a request that accepts gzip and has no Range header; otherwise the response of StaticFiles. Either is 304 Not Modified if the browser has that same file cached.

deployed_codeis_not_modified

is_not_modified(
    response_headers: Headers, request_headers: Headers
) -> bool

Whether the browser's cached copy of a file is still current.

If-None-Match, when sent, decides alone, so a cached copy in the other encoding, which has the same Last-Modified, is never taken as current.

Parameters:

• response_headers (Headers) - Headers of the response that would be sent.
• request_headers (Headers) - Headers of the request.

deployed_codelookup_path

lookup_path(
    path: str,
) -> tuple[str, os.stat_result | None]

Resolve a static file path, with SPA fallback for client-side routes.

With the path route URL strategy, route-like paths (no extension, or .html) that don't match a file fall back to index.html so the Flutter client can handle routing. Asset-like paths (any other extension) resolve to a real 404.

With the hash strategy, routes live in the URL fragment and never reach the server, so there is no fallback: any path that doesn't match a file resolves to a real 404 (with a 404.html from the assets directory as its body, if there is one), while the mount root still serves index.html.

Parameters:

• path (str) - Requested path, relative to the mounted static root (e.g. "about", "sample.json").

Returns:

• tuple[str, os.stat_result | None] - A (full_path, stat_result) tuple. When stat_result is None, Starlette responds with 404.