How to use Long Polling to Receive Events

Long polling

The example code below explains how to receive events in real-time by utilizing the API key of EQ Hub and the API implemented in the long polling method.

For a detailed explanation of the long polling method, refer to here.

The library information used in the example code is as follows.

axios: ^1.4.0

import axios, { AxiosInstance } from "axios";

const API_KEY: string = 'YOUR_API_KEY';
const END_POINT: string = 'https://ag.eqhub.eqbr.com'
let server: AxiosInstance;

server = axios.create({
  baseURL: END_POINT,
})

server.defaults.headers.common['x-eq-ag-api-key'] = API_KEY;

async function connection() {
  let response;
  try{
      console.log('enter connection')
      response = await server.get("Long Polling API URL");
      return response.data
    }catch (e) {
      if(e.status === 502){
        // HTTP Status 502 means timeout status, and occurs when the server waits for a response
        // beyond the set time.
				// The connection to the server was lost, so reconnect..
        return await connection();
      }else if(e.status === SHOULD_RECONNECT_ERROR){
        // When an error occurs, if the error requires reconnection to the server, reconnect.
        return await connection();
      }
    }
  }

Concluding

Through the above process, we learned how the client receives events from the server using the REST API implemented in the Long Polling method.