Check for a WiFi connection in a PhoneGap app and show a message if it's not available - and stop checking

connectionchecker.js

"use strict";

(function() {

  var intervalID = null;

  function startCheckingNetworkConnection() {
    intervalID = setInterval(function() {
      var networkState = navigator.connection.type;
      var isWifi = networkState == Connection.WIFI;
      var isUnknown = networkState == Connection.UNKNOWN;
      if (!isWifi && !isUnknown) {
        clearInterval(intervalID);
        // https://github.com/EddyVerbruggen/Toast-PhoneGap-Plugin
        window.plugins.toast.showLongBottom("You're not on WiFi, this may be costly!");
      }
    }, 5000);
  }

  document.addEventListener('deviceready', startCheckingNetworkConnection, false);

}());