Struct axum::extract::WebSocketUpgrade

pub struct WebSocketUpgrade { /* private fields */ }

Available on crate feature ws only.

Extractor for establishing WebSocket connections.

Note: This extractor requires the request method to be GET so it should always be used with get. Requests with other methods will be rejected.

See the module docs for an example.

Implementations

impl WebSocketUpgrade

pub fn max_send_queue(self, max: usize) -> Self

Set the size of the internal message send queue.

pub fn max_message_size(self, max: usize) -> Self

Set the maximum message size (defaults to 64 megabytes)

pub fn max_frame_size(self, max: usize) -> Self

Set the maximum frame size (defaults to 16 megabytes)

pub fn protocols<I>(self, protocols: I) -> Self where
    I: IntoIterator,
    I::Item: Into<Cow<'static, str>>, 

Set the known protocols.

If the protocol name specified by Sec-WebSocket-Protocol header to match any of them, the upgrade response will include Sec-WebSocket-Protocol header and return the protocol name.

The protocols should be listed in decreasing order of preference: if the client offers multiple protocols that the server could support, the server will pick the first one in this list.

Examples

use axum::{
    extract::ws::{WebSocketUpgrade, WebSocket},
    routing::get,
    response::IntoResponse,
    Router,
};

let app = Router::new().route("/ws", get(handler));

async fn handler(ws: WebSocketUpgrade) -> impl IntoResponse {
    ws.protocols(["graphql-ws", "graphql-transport-ws"])
        .on_upgrade(|socket| async {
            // ...
        })
}

pub fn on_upgrade<F, Fut>(self, callback: F) -> Response where
    F: FnOnce(WebSocket) -> Fut + Send + 'static,
    Fut: Future<Output = ()> + Send + 'static, 

Finalize upgrading the connection and call the provided callback with the stream.

When using WebSocketUpgrade, the response produced by this method should be returned from the handler. See the module docs for an example.

Trait Implementations

impl Debug for WebSocketUpgrade

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<B> FromRequest<B> for WebSocketUpgrade where
    B: Send, 

type Rejection = WebSocketUpgradeRejection

If the extractor fails it’ll use this “rejection” type. A rejection is a kind of error that can be converted into a response.

fn from_request<'life0, 'async_trait>(
    req: &'life0 mut RequestParts<B>
) -> Pin<Box<dyn Future<Output = Result<Self, Self::Rejection>> + Send + 'async_trait>> where
    'life0: 'async_trait,
    Self: 'async_trait, 

Perform the extraction.