title: Forcing an "Offline" Mode in Firestore
body: <p>We are building an app for our teams out in the field that they collect their daily information using Firebase. However one of our concerns is poor connectivity. We are looking to build an Online/Offline button they can click to essentially work offline for when things slow down. We've built a workflow in which we query all the relevant information from Firestore.</p>
  <p>I wanted to know if there was a way to tell Firestore to work directly on the cache only and not try to hit the servers directly. I don't want Firestore attempting to make server calls until they enable online again.</p>