woggioni
ca023580e4
- AsgiContext and AsgiWebSocket now default missing scope key to 'http' / 'ws' respectively (Daphne omits it for websocket scopes) - Add regression test for websocket scope without scheme - Update example/session.py WS handler to read the session; cookie must be set via HTTP first because common ASGI servers ignore the headers field on websocket.accept - Update README with the same caveat about Granian/Daphne/curl
85 lines
3.1 KiB
Markdown
85 lines
3.1 KiB
Markdown
# kaya-session
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Session management for the Kaya web framework.
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Provides server-side, identity-agnostic HTTP sessions via a session cookie. The
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session data is accessible from request handlers as `ctx.session`.
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## Usage
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```python
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from kaya.core import KayaApp, HttpContext
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from kaya.session import SessionMixin, InMemorySessionStore
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session = SessionMixin(InMemorySessionStore())
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app = KayaApp(mixins=[session])
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@app.GET('/')
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async def home(ctx: HttpContext):
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n = ctx.session.get('visits', 0) + 1
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ctx.session['visits'] = n
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await ctx.send_str(200, f'visits: {n}')
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```
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Sessions are created lazily: a cookie is only set when the handler modifies the
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session.
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`SessionMixin` is a `KayaMixin`, so the app stays a `KayaApp` and both ASGI and
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RSGI keep working.
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## WebSocket sessions
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The same session is available in websocket handlers as `ws.session`:
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```python
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@app.websocket('/ws/visits')
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async def ws_visits(ws: WebSocket):
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await ws.accept()
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visits = ws.session.get('visits', 0)
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await ws.send_text(f'visits: {visits}')
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```
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The session is loaded from the cookie when the connection is opened and
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persisted when the connection closes, if it was modified.
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**Important:** although the ASGI spec allows custom headers on the WebSocket
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handshake response (`websocket.accept` headers, spec 2.1+), most ASGI servers
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in practice — including **Granian** and **Daphne** — do not forward them into
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the HTTP `101` response. RSGI websocket handshakes cannot carry response headers
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at all. Therefore, in real deployments a session cookie can only be set or
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refreshed by an HTTP response. Use an HTTP endpoint to establish or update the
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session before opening the WebSocket, and read the existing session in the
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WebSocket handler.
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## Session expiry
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The cookie sent to the browser has a `Max-Age` (default 14 days), but that is
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only a client-side hint. The real boundary is the store's server-side TTL,
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which the mixin keeps in sync with the cookie `Max-Age`.
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For `InMemorySessionStore`, a session expires if it is idle for longer than
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`max_age`. Active sessions have their expiry slid forward on every access, so
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a user that keeps visiting stays logged in. If the client ignores the cookie's
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`Max-Age` and replays an old cookie value, the store rejects the expired
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session and creates a fresh empty one.
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Set `max_age=None` to disable server-side expiry (and the `Max-Age` cookie
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attribute) entirely.
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## Features
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- `Session`: dict-like session object with modification tracking
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- `SessionStore`: abstract store interface
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- `InMemorySessionStore`: simple in-memory store for development/single-process
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- `SessionMixin`: composable Kaya mixin managing session cookies and persistence
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- Session ID regeneration (`session.regenerate_id()`) and invalidation
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(`session.invalidate()`) for authentication layers
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- WebSocket support: the session is exposed as `ws.session` in websocket
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handlers, loaded at connect time and persisted on close
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## Notes
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- `InMemorySessionStore` does not survive process restarts and is not shared
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across processes. Production deployments should use a store backed by a shared
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storage system (planned).
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