Checkpoint: Data and the Device

Question 1 of 5

• Error, because an empty response is a failure.
• Loading, until at least one trail arrives.
• Error, with a Retry button, to try another server.
• Success with zero items, rendered as an empty state like “No trails within 50 km”.

Question 2 of 5

• expo-secure-store, because every setting is personal data.
• AsyncStorage (or expo-sqlite/kv-store), as part of a small JSON preferences value.
• A new SQLite table with one row and one column.
• An EXPO_PUBLIC_ environment variable.

Question 3 of 5

• The screen checked the permission only once when it mounted, instead of again when it regained focus.
• iOS needs the app to be reinstalled before a permission change applies.
• canAskAgain must be reset to true in the app’s storage.

Question 4 of 5

• They get the new column automatically on next launch.
• Their hike log is deleted and recreated.
• Nothing changes for them, so queries that use difficulty fail with “no such column”.
• SQLite rejects the database file at startup.

Question 5 of 5

• Switch to Accuracy.Lowest to save battery.
• Round each coordinate to three decimal places.
• Ignore readings whose coords.accuracy exceeds a threshold before adding them to the route.
• Multiply the result by a correction factor of 0.65.