I'm kinda new to ReactJS, learning and making one project.
And i got stuck with such an issue.  

I have app with authorization. User enters credentials and proceeds to app.
There is a navigation menu made using external libraries. It slides up and down and initializes with something like

```
$(document).ready(function(){
  $('.menu-class').makeCoolMenu();
}); 

```

But, when user is not signed in - app not showing menu. This code runs and does nothing.
After authorization menu appears, but of course not working.  

I googled it, but found nothing about it. Just something about "dont use jquery with React". But what is the correct way to do such thing? Seems like i cant run 

```
$('.menu-class').makeCoolMenu();

```

from within the application.

Thanks in advance.