nestjs-sse/dist/index.js

Middleware for Nest.js to broadcast Server-Sent Events (SSE)

"use strict";
var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
    return c > 3 && r && Object.defineProperty(target, key, r), r;
};
Object.defineProperty(exports, "__esModule", { value: true });
const common_1 = require("@nestjs/common");
let SSEMiddleware = class SSEMiddleware {
    use(req, res, next) {
        req.socket.setKeepAlive(true);
        req.socket.setTimeout(0);
        res.setHeader("Content-Type", "text/event-stream");
        res.setHeader("Cache-Control", "no-cache");
        res.setHeader("Connection", "keep-alive");
        res.status(200);
        // export a function to send server-side-events
        res.sse = function sse(data) {
            res.write(data);
            // support running within the compression middleware
            // @ts-ignore
            if (res.flushHeaders() && data.match(/\n\n$/)) {
                res.flushHeaders();
            }
        };
        // write 2kB of padding (for IE) and a reconnection timeout
        // then use res.sse to send to the client
        res.write(":" + Array(2049).join(" ") + "\n");
        res.sse("retry: 2000\n\n");
        // keep the connection open by sending a comment
        const keepAlive = setInterval(() => {
            res.sse(":keep-alive\n\n");
        }, 20000);
        // cleanup on close
        res.on("close", function close() {
            clearInterval(keepAlive);
        });
        next();
    }
};
SSEMiddleware = __decorate([
    common_1.Injectable()
], SSEMiddleware);
exports.SSEMiddleware = SSEMiddleware;