title: How to handle network requests that have to be finished in swift
body: <p>So I'm currently stuck because the App I'm developing is handling network requests and I'm quite new to it. 
  The App needs to load some data first in order to even work properly. So I tried to execute the network request in the AppDelegate. However, as I understand it, network requests run asynchronously, which is why my table view does not load properly. So I tried reloading the tableview after the network request finished, which worked, but gave me the following message: </p>
  
  <blockquote>
    <p>UITableView.reloadData() must be used from main thread only</p>
  </blockquote>
  
  <p>My question is how to properly handle such a situation. What is the industry standard? </p>