title: cordova is undefined when using the Cordova local notification plugin
body: <p>I am a beginner in Ionic. Recently I am trying to use the Cordova local notifications plugin. By following the Ionic documentation at <a href="https://ionicframework.com/docs/native/local-notifications/" rel="nofollow noreferrer">https://ionicframework.com/docs/native/local-notifications/</a> and the tutorial at <a href="https://www.joshmorony.com/getting-familiar-with-local-notifications-in-ionic-2" rel="nofollow noreferrer">https://www.joshmorony.com/getting-familiar-with-local-notifications-in-ionic-2</a>, I was able to set up some notifications for my app. The plugin version is 0.9.0-beta.2.</p>
  
  <p>However I ran into problem when I tried to set up repeating notifications. Not knowing what to do, I read the following documentation: </p>
  
  <p><a href="https://github.com/katzer/cordova-plugin-local-notifications/blob/master/README.md" rel="nofollow noreferrer">https://github.com/katzer/cordova-plugin-local-notifications/blob/master/README.md</a></p>
  
  <p>Then I found that there are different ways to do the notification for my plugin version. In particular, the github document instructs the use of <code>cordova.plugins.notification.local.schedule(...)</code> instead of <code>this.localNotifications.schedule(...)</code>. This is confusing to me as a beginner as I don't know how to deal with this inconsistency. When I follow the new approach, it is said that cordova is not defined. I think this makes sense, but I cannot find any full example to show me how to get it work.</p>
  
  <p>My questions:</p>
  
  <ol>
  <li>How can I use the notification plugin the appropriate way?</li>
  <li>Where can I find some up-to-date full example for that? </li>
  </ol>
  
  <p>I am eager to learn but it is sometimes frustrating to get stuck in    documentations and tutorials only to find later that they are already outdated. Any general advice would also be appreciated.</p>
  
  <p>Thank you in advance.</p>