1 files changed, 18 insertions, 0 deletions
diff --git a/Firestore/Source/Core/FSTView.m b/Firestore/Source/Core/FSTView.m
index 9b44bf4..d539bb6 100644
--- a/Firestore/Source/Core/FSTView.m
+++ b/Firestore/Source/Core/FSTView.m
@@ -330,6 +330,24 @@ static NSComparisonResult FSTCompareDocumentViewChangeTypes(FSTDocumentViewChang
   }
 }
 
+- (FSTViewChange *)applyOnlineStateChange:(FSTOnlineState)onlineState {
+  if (self.isCurrent && onlineState == FSTOnlineStateFailed) {
+    // If we're offline, set `current` to NO and then call applyChanges to refresh our syncState
+    // and generate an FSTViewChange as appropriate. We are guaranteed to get a new FSTTargetChange
+    // that sets `current` back to YES once the client is back online.
+    self.current = NO;
+    return
+        [self applyChangesToDocuments:[[FSTViewDocumentChanges alloc]
+                                          initWithDocumentSet:self.documentSet
+                                                    changeSet:[FSTDocumentViewChangeSet changeSet]
+                                                  needsRefill:NO
+                                                  mutatedKeys:self.mutatedKeys]];
+  } else {
+    // No effect, just return a no-op FSTViewChange.
+    return [[FSTViewChange alloc] initWithSnapshot:nil limboChanges:@[]];
+  }
+}
+
 #pragma mark - Private methods
 
 /** Returns whether the doc for the given key should be in limbo. */