Struct Event 

pub struct Event { /* private fields */ }

A Server-Sent Event to be delivered to a connected client.

Uses a builder pattern. id and event name are required at construction and validated — \n and \r are rejected.

Examples

use modo::sse::Event;

let event = Event::new("evt_01", "message")?.data("Hello, world!");
let event = Event::new(modo::id::short(), "status")?.json(&status)?;
let event = Event::new(modo::id::short(), "update")?.html("<div>new</div>");

Implementations

impl Event

pub fn new( id: impl Into<String>, event: impl Into<String>, ) -> Result<Self, Error>

Create a new event. Both id and event are required.

• id maps to the SSE id: field — used by clients for Last-Event-ID on reconnection.
• event maps to the SSE event: field — clients listen for specific event types (e.g., eventSource.addEventListener("message", handler) or HTMX hx-trigger="sse:message").

Errors

Returns an error if id or event contain \n or \r.

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

Set the data payload as a plain string.

Multi-line strings are handled automatically per the SSE spec — each line gets its own data: prefix. The browser reassembles them with \n.

pub fn json<T: Serialize>(self, data: &T) -> Result<Self, Error>

Set the data payload as JSON-serialized data.

Replaces any previous data.

Errors

Returns an error if JSON serialization fails.

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

Set the data payload as an HTML fragment.

Semantically identical to data(). Communicates intent for HTMX partial rendering use cases.

pub fn retry(self, duration: Duration) -> Self

Set the reconnection delay hint for the client.

Serialized as milliseconds in the SSE retry: field. Tells the browser how long to wait before reconnecting after a disconnect.

pub fn id(&self) -> &str

Returns the event ID.

pub fn event_name(&self) -> &str

Returns the event name.

pub fn data_ref(&self) -> Option<&str>

Returns the data payload, if set.

Trait Implementations

impl Clone for Event

fn clone(&self) -> Event

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Event

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

Formats the value using the given formatter.

impl From<Event> for Event

fn from(event: Event) -> Self

Converts to this type from the input type.