zulip-desktop/app/renderer/js/utils/reconnect-util.js

const isOnline = require('is-online');

class ReconnectUtil {
	constructor(serverManagerView) {
		this.serverManagerView = serverManagerView;
		this.alreadyReloaded = false;
	}

	clearState() {
		this.alreadyReloaded = false;
	}

	pollInternetAndReload() {
		const pollInterval = setInterval(() => {
			this._checkAndReload()
			.then(status => {
				if (status) {
					this.alreadyReloaded = true;
					clearInterval(pollInterval);
				}
			});
		}, 1500);
	}

	_checkAndReload() {
		return new Promise(resolve => {
			if (!this.alreadyReloaded) { // eslint-disable-line no-negated-condition
				isOnline()
				.then(online => {
					if (online) {
						if (!this.alreadyReloaded) {
							this.serverManagerView.reloadView();
						}
						console.log('You\'re back online.');
						return resolve(true);
					}

					console.log('There is no internet connection, try checking network cables, modem and router.');
					const errMsgHolder = document.querySelector('#description');
					errMsgHolder.innerHTML = `
										<div>You internet connection does't seem to work properly!</div>
										</div>Verify that it works and then click try again.</div>`;
					return resolve(false);
				});
			} else {
				return resolve(true);
			}
		});
	}
}

module.exports = ReconnectUtil;