Feathersjs know when server is offline(from the client)

Question

I have an Angular app that connects to the Feathers API with socket.io and feathers-reactive using @feathersjs/authentication-client. This works great!

This is my client code:

import * as feathersRx from 'feathers-reactive';
import * as io from 'socket.io-client';
import feathers from '@feathersjs/feathers';
import feathersSocketIOClient from '@feathersjs/socketio-client';

export function fInit(options: FeathersOptions): void {
    // eslint-disable-next-line @typescript-eslint/no-var-requires
    const _feathersAuthClient = require('@feathersjs/authentication-client').default;
    const _feathersApp = feathers();

    const _socket: SocketIOClient.Socket = io(options.feathersIP, {
        transports: ['websocket'],
        forceNew: true
    });

    _feathersApp.configure(feathersSocketIOClient(_socket))
        .configure(_feathersAuthClient({
            storage: options.storage
        }))
        .configure(feathersRx({
            idField: '_id'
        }));
}

In this scenario I just started the app but not the API. Feathers gets initialized and looks for the server not finding it.

What I would like to know in the Angular app is when is the server down?

Is there any type of event, subscription, callback or anything else that I can get from the above code whenever an error like this occurs?

Any help/tip/pointer with this matter is greatly appreciated!

Thanks in advance

*Given the nature of the config with all the socketio, authentication-client, and feathers-reactive, I don't even know where the error is coming from.

Answer 1

So the message/error is from socket.io and socket.io has the following events that you can listen to like:

_socket.on("disconnect", () => changeServerState('disconnected'));
_socket.on("connect", () => changeServerState('connected'));
_socket.on("connect_error", () => changeServerState('error'));
_socket.on("connect_timeout", () => changeServerState('connect_timeout'));