Struct SseEvent 

pub struct SseEvent {
    pub event_type: Option<String>,
    pub data: Value,
    pub id: Option<String>,
    pub retry: Option<u64>,
}

An individual SSE event

Represents a single Server-Sent Event to be sent to a connected client. Events can have an optional type, ID, and retry timeout for advanced scenarios.

Fields

• event_type - Optional event type string (used for client-side event filtering)
• data - JSON data payload to send to the client
• id - Optional event ID (clients can use this to resume after disconnect)
• retry - Optional retry timeout in milliseconds (tells client when to reconnect)

SSE Format

Events are serialized to the following text format:

event: event_type
data: {"json":"value"}
id: event-123
retry: 3000

Fields

event_type: Option<String>

Event type (optional)

data: Value

Event data (JSON value)

id: Option<String>

Event ID (optional, for client-side reconnection)

retry: Option<u64>

Retry timeout in milliseconds (optional)

Implementations

impl SseEvent

pub fn new(data: Value) -> Self

Create a new SSE event with data only

Creates a minimal event with just the data payload. Use builder methods to add optional fields.

Arguments

• data - JSON value to send to the client

Example

use serde_json::json;
use spikard_http::sse::SseEvent;

let event = SseEvent::new(json!({"status": "connected"}));

pub fn with_type(event_type: impl Into<String>, data: Value) -> Self

Create a new SSE event with an event type and data

Creates an event with a type field. Clients can filter events by type in their event listener.

Arguments

• event_type - String identifying the event type (e.g., “update”, “error”)
• data - JSON value to send to the client

Example

use serde_json::json;
use spikard_http::sse::SseEvent;

let event = SseEvent::with_type("update", json!({"count": 42}));
// Client can listen with: eventSource.addEventListener("update", ...)

pub fn with_id(self, id: impl Into<String>) -> Self

Set the event ID for client-side reconnection support

Sets an ID that clients can use to resume from this point if they disconnect. The client sends this ID back in the Last-Event-ID header when reconnecting.

Arguments

• id - Unique identifier for this event

Example

use serde_json::json;
use spikard_http::sse::SseEvent;

let event = SseEvent::new(json!({"count": 1}))
    .with_id("event-1");

pub fn with_retry(self, retry_ms: u64) -> Self

Set the retry timeout for client reconnection

Sets the time in milliseconds clients should wait before attempting to reconnect if the connection is lost. The client browser will automatically handle reconnection.

Arguments

• retry_ms - Retry timeout in milliseconds

Example

use serde_json::json;
use spikard_http::sse::SseEvent;

let event = SseEvent::new(json!({"data": "value"}))
    .with_retry(5000); // Reconnect after 5 seconds

Trait Implementations

impl Clone for SseEvent

fn clone(&self) -> SseEvent

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SseEvent

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

Formats the value using the given formatter.