sse-js

Server-Sent Events JavaScript Library

This is a small JavaScript client to handle Server-Sent Events. It is not the server, only the client. This singleton class exposes a few methods to subscribe to events, unsubscribe, and close an active connection. Additional methods to enable/disable debug mode are available. In debug mode, some information will be output to the console.

See below instructions to install and use the library.

Installation

npm i --save @vallejos/sse-js

Examples and Documentation

Node.js

const SSE = require('sse-js');

const client = new SSE(url);
Object.freeze(client);

export default client;

Browser

<script src="dist/sse-js.min.js"></script>
<script>
    const sseClient = new SSE(url);
    Object.freeze(sseClient);

    export default sseClient;
</script>

constructor

const sseClient = new SSE(url, withCredentials, debug);

Parameters:

• url: {string} an URL or path to the server sending the events. The client will establish a connection to this url.
• withCredentials: {boolean} indicates wheter to use credentials or not
• debug: {boolean} a boolean indicating whether to enable debug mode or not

close connection

close();

subscribe to an event

const subscriberId = subscribe(cb, event, error);

The subscribe method will return a unique ID (a string). This ID can be used later to call the unsubscribe mehtod. Parameters:

• cb: {function} a callback function that will be run when an event is matched - required
• event: {string|null} the name of the event or null to subscribe to all events
• error: {function} a callback function that will be run when an error occurs

unsubscribe from events

unsubscribe(subscriberId);

Parameters:

• subscriberId: {string} a unique subscriber ID (returned from the subscribe method)

enable debug

enableDebug();

disable debug

disableDebug();

Contributing

All PRs are welcome :)

LICENSE

a relative link