title: Firestore Swift Network Detection
body: <p>I'm trying to include a banner in my app to alert users when they lose connection to Firebase. I don't need this written into the database, I just need to alert clients locally. RDTD seems to include presence detection that publishes this data to GC, but I don't need something that advanced.</p>
  
  <p>I simply want to trigger a local function when the connection to Firebase changes. How can I do this?</p>