n8n/packages/cli/src/Push.ts

97 lines
2.2 KiB
TypeScript

// @ts-ignore
import * as sseChannel from 'sse-channel';
import * as express from 'express';
import {
IPushData,
IPushDataType,
} from '.';
export class Push {
private channel: sseChannel;
private connections: {
[key: string]: express.Response;
} = {};
constructor() {
this.channel = new sseChannel({
cors: {
// Allow access also from frontend when developing
origins: ['http://localhost:8080'],
},
});
this.channel.on('disconnect', (channel: string, res: express.Response) => {
if (res.req !== undefined) {
delete this.connections[res.req.query.sessionId];
}
});
}
/**
* Adds a new push connection
*
* @param {string} sessionId The id of the session
* @param {express.Request} req The request
* @param {express.Response} res The response
* @memberof Push
*/
add(sessionId: string, req: express.Request, res: express.Response) {
if (this.connections[sessionId] !== undefined) {
// Make sure to remove existing connection with the same session
// id if one exists already
this.connections[sessionId].end();
this.channel.removeClient(this.connections[sessionId]);
}
this.connections[sessionId] = res;
this.channel.addClient(req, res);
}
/**
* Sends data to the client which is connected via a specific session
*
* @param {string} sessionId The session id of client to send data to
* @param {string} type Type of data to send
* @param {*} data
* @memberof Push
*/
send(type: IPushDataType, data: any, sessionId?: string) { // tslint:disable-line:no-any
if (sessionId !== undefined && this.connections[sessionId] === undefined) {
// TODO: Log that properly!
console.error(`The session "${sessionId}" is not registred.`);
return;
}
const sendData: IPushData = {
type,
data,
};
if (sessionId === undefined) {
// Send to all connected clients
this.channel.send(JSON.stringify(sendData));
} else {
// Send only to a specific client
this.channel.send(JSON.stringify(sendData), [this.connections[sessionId]]);
}
}
}
let activePushInstance: Push | undefined;
export function getInstance(): Push {
if (activePushInstance === undefined) {
activePushInstance = new Push();
}
return activePushInstance;
}