title: Best practices for updating local JSON data file in Swift app?
body: <p>My app will ship with a local JSON file for the data, so that everything functions properly offline (because the region the app is based on is hit or miss on connections).  I would like to be able to update the local file from time to time with an updated version that is hosted on a server.</p>
  
  <p>Should I download the updated file and overwrite the local file with it, or is there a way to check to see if the file has been updated before downloading?  </p>
  
  <p>Also, what event would be best to do these type of tasks on?  Downloading the file and overwriting the local copy every time the app runs seems like overkill, but I don't really know how I would go about checking the server file to see if the file is newer before downloading.</p>
  
  <p>I'm new to programming in general, so I don't really know the best practices way to handle something like this.</p>
  
  <p>Any help is appreciated.</p>