title: How to handle a file sent with 'Open in...' from another app to my own iOS app?
body: <p>I am developing an app that reads csv files and display its content in a tableViewController. When doing my testings using Xcode, I have a sample file within the projects directory and I am perfectly able to read that file using its location path. The problem that I have is I want to be able to take any csv file (sent to me via some method), click the 'Open in' button and have the file sent to my app.</p>
  <p>My app is being displayed in the available applications to which I can send the file to. My question is what happens after? When I choose to send it to my app it then switches over to my app and from there, I don't know how to receive the file and read it to extract its content. Where does the file go and how do I interact with it?</p>