Function use_event_source

pub fn use_event_source<T, C>(
    url: &str,
) -> UseEventSourceReturn<T, C::Error, impl Fn() + Clone + 'static, impl Fn() + Clone + 'static>
where
    T: Clone + PartialEq + 'static,
    C: Decoder<T, Encoded = str>,

Reactive EventSource

An EventSource or Server-Sent-Events instance opens a persistent connection to an HTTP server, which sends events in text/event-stream format.

Usage

Values are decoded via the given decoder. You can use any of the string codecs or a binary codec wrapped in Base64.

Please check the codec chapter to see what codecs are available and what feature flags they require.

#[derive(Serialize, Deserialize, Clone, PartialEq)]
pub struct EventSourceData {
    pub message: String,
    pub priority: u8,
}

let UseEventSourceReturn {
    ready_state, data, error, close, ..
} = use_event_source::<EventSourceData, JsonSerdeCodec>("https://event-source-url");

Named Events

You can define named events when using use_event_source_with_options.

let UseEventSourceReturn {
    ready_state, data, error, close, ..
} = use_event_source_with_options::<String, FromToStringCodec>(
    "https://event-source-url",
    UseEventSourceOptions::default()
        .named_events(["notice".to_string(), "update".to_string()])
);

Immediate

Auto-connect (enabled by default).

This will call open() automatically for you, and you don’t need to call it by yourself.

Auto-Reconnection

Reconnect on errors automatically (enabled by default).

You can control the number of reconnection attempts by setting reconnect_limit and the interval between them by setting reconnect_interval.

let UseEventSourceReturn {
    ready_state, data, error, close, ..
} = use_event_source_with_options::<bool, FromToStringCodec>(
    "https://event-source-url",
    UseEventSourceOptions::default()
        .reconnect_limit(ReconnectLimit::Limited(5))         // at most 5 attempts
        .reconnect_interval(2000)   // wait for 2 seconds between attempts
);

To disable auto-reconnection, set reconnect_limit to 0.

Server-Side Rendering

On the server-side, use_event_source will always return ready_state as ConnectionReadyState::Closed, data, event and error will always be None, and open and close will do nothing.