Offline Mode¶

ShopSync is built with an offline-first architecture, allowing you to use all core features without an internet connection.

How Offline Mode Works¶

Automatic Detection¶

ShopSync automatically detects your connection status:

• Online - Green indicator, real-time sync enabled
• Offline - Orange indicator, changes saved locally

Local Storage¶

When offline, all data is stored on your device:

• View all your lists
• Add new items
• Edit existing items
• Check off items
• Create new lists
• Delete items (moved to local recycle bin)

Automatic Sync¶

When you reconnect:

• All local changes automatically sync to cloud
• Changes from other devices download
• Conflicts resolved automatically
• Sync status shown briefly

What Works Offline¶

✅ Available Features¶

❌ Limited Features¶

Using ShopSync Offline¶

Best Practices¶

Viewing Offline Status¶

The offline indicator appears:

• Top of home screen - Connection status banner
• List view - Sync status per list
• Settings - Last sync timestamp

Managing Local Data¶

Check local storage usage:

1. Go to Settings → Storage
2. See:
3. Total local data size
4. Number of cached lists
5. Number of pending sync items
6. Last successful sync time

Conflict Resolution¶

How Conflicts Happen¶

Conflicts occur when:

• You edit offline
• Another user edits the same item online
• You reconnect before syncing

Automatic Resolution¶

ShopSync uses intelligent conflict resolution:

1. Last Write Wins - Most recent change takes precedence
2. Field-Level Merging - Different fields don't conflict
3. Addition Priority - New items always added
4. Check Status Preserved - Checked items stay checked

Manual Resolution¶

If automatic resolution isn't possible:

1. The list shows a conflict status
2. View both versions
3. Choose which to keep
4. Or merge manually

Offline Storage Limits¶

Storage Capacity¶

• Android: Up to 100 MB local storage
• Web: Up to 50 MB (browser dependent)
• WearOS: Up to 10 MB

When Storage is Full¶

1. Oldest cached data is cleared first
2. Active lists are prioritized
3. Storage status shows when you're near the limit

Clearing Offline Data¶

To free up space:

1. Go to Settings → Storage
2. Tap Clear Cache
3. Select what to clear:
4. Cached images
5. Old deleted items
6. Unused list data
7. Tap Clear

Recently accessed lists won't be cleared to prevent data loss.

Sync Status Indicators¶

List-Level Status¶

Each list shows sync status:

• ☁️ Synced - Up to date with cloud
• 🔄 Syncing - Currently uploading changes
• 📴 Offline - Changes pending sync
• ⚠️ Conflict - Manual resolution needed
• ❌ Error - Sync failed, will retry

Item-Level Status¶

Items show if they have pending changes:

• 📝 Modified - Local edits not synced
• ➕ New - Created offline
• 🗑️ Deleted - Marked for deletion
• ✅ Synced - Up to date

Troubleshooting Offline Mode¶

Changes Not Syncing¶

1. Check connection - Ensure WiFi/cellular is active
2. Force sync - Pull down on home screen to refresh
3. Restart app - Close and reopen ShopSync
4. Check storage - Ensure device has space
5. Update app - Latest version may fix issues

Items Disappeared¶

1. Wait for sync - Items may be downloading
2. Check recycle bin - May have been deleted
3. Verify account - Ensure correct account signed in
4. Contact support - If data seems lost

Duplicate Items¶

Sometimes items appear twice after sync:

1. Usually resolves automatically
2. Delete duplicate manually if it persists
3. Report if issue continues

Slow Sync¶

If syncing takes too long:

1. Check internet speed
2. Reduce number of pending changes
3. Close other apps using network
4. Try syncing on WiFi instead of cellular

Offline Mode Settings¶

Configure Offline Behavior¶

1. Go to Settings → Offline & Sync
2. Configure:
3. Auto-sync - Sync when online (recommended)
4. Sync frequency - How often to check for updates
5. WiFi only - Don't sync on cellular data
6. Background sync - Sync even when app is closed
7. Cache size - How much storage to use

Sync Preferences¶

=== "Automatic (Recommended)" - Syncs immediately when online - Best for real-time collaboration - Uses more battery/data

=== "Manual" - You control when to sync - Better for limited data plans - Pull down to refresh manually

=== "WiFi Only" - Only syncs on WiFi - Saves cellular data - Good for large lists

Data Safety¶

Backup Strategy¶

ShopSync uses multiple layers of protection:

1. Local cache - On your device
2. Cloud storage - Firebase Firestore
3. Sync queue - Pending changes tracked
4. Conflict copies - Versions preserved

Data Loss Prevention¶

• Changes saved immediately to local storage
• Sync queue persists even if app closes
• Failed syncs automatically retry
• Cloud backup protects against device loss

Best Practices for Offline Use¶

!!! tip "Offline Shopping Tips" - Sync before entering store - Update with latest changes - Use airplane mode strategically - Save battery while shopping - Make all changes freely - Don't worry about conflicts - Sync after shopping - Upload your changes when done - Check pending items - Verify everything synced

!!! tip "Traveling Without Internet" - Download lists beforehand - Open each list while online - Create lists offline - They'll sync when you connect - Don't sign out - Stay logged in during trip - Monitor storage - Keep some space available

Technical Details¶

Caching Strategy¶

ShopSync uses intelligent caching:

• Recently accessed lists cached with high priority
• Images lazy-loaded and cached
• Shared lists pre-fetched
• Stale data refreshed in background

Sync Algorithm¶

1. Detect connection state change
2. Collect pending local changes
3. Upload changes to Firestore
4. Download remote changes
5. Resolve any conflicts
6. Update local cache
7. Mark sync as complete in the app

Next Steps¶

• Real-time Sync
• Sharing & Collaboration
• Settings & Preferences

Questions? Check the FAQ for more information.