Struct socketioxide::handler::extract::State

pub struct State<T: 'static>(pub &'static T);

Available on crate feature state only.

An Extractor that contains a reference to a state previously set with SocketIoBuilder::with_state. It implements std::ops::Deref to access the inner type so you can use it as a normal reference.

The specified state type must be the same as the one set with SocketIoBuilder::with_state. If it is not the case, the handler won’t be called and an error log will be print if the tracing feature is enabled.

The state is shared between the entire socket.io app context.

Example

#[derive(Default)]
struct MyAppData {
    user_cnt: AtomicUsize,
}
impl MyAppData {
    fn add_user(&self) {
        self.user_cnt.fetch_add(1, Ordering::SeqCst);
    }
    fn rm_user(&self) {
        self.user_cnt.fetch_sub(1, Ordering::SeqCst);
    }
}
let (_, io) = SocketIo::builder().with_state(MyAppData::default()).build_svc();
io.ns("/", |socket: SocketRef, state: State<MyAppData>| {
    state.add_user();
    println!("User count: {}", state.user_cnt.load(Ordering::SeqCst));
});

Tuple Fields

0: &'static T

Trait Implementations

impl<T> Deref for State<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<A: Adapter, T: Send + Sync + 'static> FromConnectParts<A> for State<T>

type Error = StateNotFound

The error type returned by the extractor

fn from_connect_parts( _: &Arc<Socket<A>>, _: &Option<String> ) -> Result<Self, StateNotFound>

Extract the arguments from the connect event. If it fails, the handler is not called

impl<A: Adapter, T: Send + Sync + 'static> FromDisconnectParts<A> for State<T>

type Error = StateNotFound

The error type returned by the extractor

fn from_disconnect_parts( _: &Arc<Socket<A>>, _: DisconnectReason ) -> Result<Self, StateNotFound>

Extract the arguments from the disconnect event. If it fails, the handler is not called

impl<A: Adapter, T: Send + Sync + 'static> FromMessageParts<A> for State<T>

type Error = StateNotFound

The error type returned by the extractor

fn from_message_parts( _: &Arc<Socket<A>>, _: &mut Value, _: &mut Vec<Vec<u8>>, _: &Option<i64> ) -> Result<Self, StateNotFound>

Extract the arguments from the message event. If it fails, the handler is not called.