Class EventSource<S>

Client-side typed wrapper around the browser's native EventSource.

This class:

enforces typed application events based on App.Events
centralizes all decoding into a single pipeline
implements a protocol-level control channel (magic events)
provides chainable helper methods (on, once, off)

Example

const es = new EventSource<"status">("/sse");

es.onOpen(() => console.log("connected"));
es.on("heartbeat", (n) => console.log(n));
es.onClose(() => console.log("closed"));

Type Parameters

S extends keyof App.Events
Stream name (key of App.Events)

Implements

TypedEventTarget<TypedEventSourceEventMap<S>>

Index

Constructors

constructor

new EventSource<S extends "status">(
url: string | URL,
init?: ClientInit<S>,
): EventSource<S>
Create a new client-side SSE connection.
Type Parameters
- S extends "status"
  Stream name (key of App.Events)
Parameters
- url: string | URL
  SSE endpoint URL
- init: ClientInit<S> = {}
  Client configuration options
Returns EventSource<S>
- Defined in src/lib/client/index.ts:182

Accessors

readyState

get readyState(): number
Native readyState of the underlying EventSource.

Returns number
- Defined in src/lib/client/index.ts:197

url

get url(): string
Resolved URL of the EventSource connection.

Returns string
- Defined in src/lib/client/index.ts:202

withCredentials

get withCredentials(): boolean
Whether credentials are sent with the EventSource request.

Returns boolean
- Defined in src/lib/client/index.ts:207

Methods

addEventListener

addEventListener<K extends string | number | symbol>(
    type: K,
    listener: (event: CustomEvent<TypedEventSourceEventMap<S>[K]>) => void,
    options?: boolean | AddEventListenerOptions,
): void
Add a typed event listener.
Type Parameters
- K extends string | number | symbol
Parameters
- type: K
- listener: (event: CustomEvent<TypedEventSourceEventMap<S>[K]>) => void
- Optionaloptions: boolean | AddEventListenerOptions
Returns void
Implementation of TypedEventTarget.addEventListener
- Defined in src/lib/client/index.ts:342

close

close(): void
Close the connection (client-initiated).

Emits a close event with { initiator: "client" }.

Returns void
- Defined in src/lib/client/index.ts:216

dispatch

dispatch<K extends string | number | symbol>(
type: K,
detail: TypedEventSourceEventMap<S>[K],
): boolean
Dispatch a typed event.
Type Parameters
- K extends string | number | symbol
Parameters
- type: K
- detail: TypedEventSourceEventMap<S>[K]
Returns boolean
Implementation of TypedEventTarget.dispatch
- Defined in src/lib/client/index.ts:378

dispatchEvent

dispatchEvent(event: Event): boolean
Dispatch a raw event.
Parameters
- event: Event
Returns boolean
Implementation of TypedEventTarget.dispatchEvent
- Defined in src/lib/client/index.ts:388

off

off<K extends string | number | symbol>(
eventType: K,
listener: (data: Events[S][K]) => void,
): this
Remove a listener previously registered with on or once.
Type Parameters
- K extends string | number | symbol
Parameters
- eventType: K
- listener: (data: Events[S][K]) => void
Returns this
- Defined in src/lib/client/index.ts:475

on

on<K extends string | number | symbol>(
eventType: K,
listener: (data: Events[S][K]) => void,
): this
Listen to a typed application event.
Type Parameters
- K extends string | number | symbol
Parameters
- eventType: K
- listener: (data: Events[S][K]) => void
Returns this
- Defined in src/lib/client/index.ts:439

once

once<K extends string | number | symbol>(
eventType: K,
listener: (data: Events[S][K]) => void,
): this
Listen once to a typed application event.
Type Parameters
- K extends string | number | symbol
Parameters
- eventType: K
- listener: (data: Events[S][K]) => void
Returns this
- Defined in src/lib/client/index.ts:457

onClose

onClose(
listener: (e: CustomEvent<{ initiator: "server" | "client" }>) => void,
): this
Register a close listener.
Parameters
- listener: (e: CustomEvent<{ initiator: "server" | "client" }>) => void
Returns this
- Defined in src/lib/client/index.ts:408

onError

onError(listener: (error: Event) => void): this
Register an error listener.
Parameters
- listener: (error: Event) => void
Returns this
- Defined in src/lib/client/index.ts:399

onMessage

onMessage(listener: (data: any) => void): this
Register a message listener.
Parameters
- listener: (data: any) => void
Returns this
- Defined in src/lib/client/index.ts:414

onOpen

onOpen(listener: () => void): this
Register an open listener.
Parameters
- listener: () => void
Returns this
- Defined in src/lib/client/index.ts:393

removeEventListener

removeEventListener<K extends string | number | symbol>(
    type: K,
    listener: (event: CustomEvent<TypedEventSourceEventMap<S>[K]>) => void,
    options?: boolean | EventListenerOptions,
): void
Remove a typed event listener.
Type Parameters
- K extends string | number | symbol
Parameters
- type: K
- listener: (event: CustomEvent<TypedEventSourceEventMap<S>[K]>) => void
- Optionaloptions: boolean | EventListenerOptions
Returns void
Implementation of TypedEventTarget.removeEventListener
- Defined in src/lib/client/index.ts:359

Class EventSource<S>

Example

Type Parameters

Implements

Index

Constructors

Accessors

Methods

Constructors

constructor

Type Parameters

Parameters

Returns EventSource<S>

Accessors

readyState

Returns number

url

Returns string

withCredentials

Returns boolean

Methods

addEventListener

Type Parameters

Parameters

Returns void

close

Returns void

dispatch

Type Parameters

Parameters

Returns boolean

dispatchEvent

Parameters

Returns boolean

off

Type Parameters

Parameters

Returns this

on

Type Parameters

Parameters

Returns this

once

Type Parameters

Parameters

Returns this

onClose

Parameters

Returns this

onError

Parameters

Returns this

onMessage

Parameters

Returns this

onOpen

Parameters

Returns this

removeEventListener

Type Parameters

Parameters

Returns void

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