socket.io-requests/index.js

Better requests functionality for Socket.io - Server & Client.

"use strict";

const REQUESTPREFIX = "SioR-Request-";
const RESPONSEPREFIX = "SioR-Response-";

class SocketRequest {
  timeout = 30000;

  constructor(socket) {
    this.socket = socket;
    this.createFunctions();
  }

  createFunctions() {
    this.createSendFunction();
    this.createOnRequestFunction();
    this.createOnAnyRequestFunction();
  }

  createSendFunction() {
    this.socket.sendRequest = (event, bodyData, timeout = this.timeout) =>
      new Promise((resolve, reject) => {
        const request = {
          uuid: SocketRequest.createUUID(),
          event: event,
          body: bodyData,
        };
        this.socket.emit(REQUESTPREFIX + event, request);
        let active = true;
        setTimeout(() => {
          active = false;
          reject(`Timeout. The request has expired after ${timeout} ms.`);
        }, timeout);
        this.socket.on(RESPONSEPREFIX + request.uuid, (response) => {
          if (active) resolve(response);
        });
      });
  }

  createOnRequestFunction() {
    this.socket.onRequest = (event, handler) => {
      this.socket.on(REQUESTPREFIX + event, (data) => {
        handler(data.body, (responseData) => {
          this.socket.emit(RESPONSEPREFIX + data.uuid, responseData);
        }, data.uuid);
      });
    };
  }

  createOnAnyRequestFunction() {
    this.socket.onAnyRequest = (handler) => {
      this.socket.onAny((event, data) => {
        if (event.includes(REQUESTPREFIX)) {
          handler(data.event, data.body, (responseData) => {
            this.socket.emit(RESPONSEPREFIX + data.uuid, responseData);
          }, data.uuid);
        }
      });
    };
  }

  static createUUID() {
    let d = new Date().getTime();
    let d2 =
      (typeof performance !== "undefined" &&
        performance.now &&
        performance.now() * 1000) ||
      0;
    return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(
      /[xy]/g,
      function (c) {
        let r = Math.random() * 16;
        if (d > 0) {
          r = (d + r) % 16 | 0;
          d = Math.floor(d / 16);
        } else {
          r = (d2 + r) % 16 | 0;
          d2 = Math.floor(d2 / 16);
        }
        return (c === "x" ? r : (r & 0x3) | 0x8).toString(16);
      }
    );
  }
}

module.exports = (socket) => new SocketRequest(socket);