Saving

Saving changes in p2d2 follows a structured process to prevent data loss and enable quality assurance.

Save Workflow

1. Local Saving

During editing, changes are saved locally in the browser:

• Automatically: Every 30 seconds
• Manually: Ctrl + S or "Save" button
• Browser Storage: IndexedDB

Auto-Save

You don't need to save manually - the application automatically saves your work.

2. Mark Changes

Edited features are marked:

• Yellow: Unsaved local changes
• Orange: Marked for quality assurance
• Green: Quality assured, ready for export

3. Submit for Quality Assurance

When you're satisfied with your work:

1. Select Feature
2. "Submit for QA": Button in the sidebar
3. Comment: Describe changes
4. Confirm

The feature is now submitted to the community for review.

Storage Locations

Browser (IndexedDB)

• Local Cache: For offline editing
• Automatic Synchronization: When online connection
• Versioning: Multiple editing states

Server (PostgreSQL/PostGIS)

• After QA Submission: Data is transferred to server
• Versioning: Git-like change history
• Backup: Daily backups

Export

After successful quality assurance:

• OpenStreetMap: Via OSM-API
• WikiData: Via WikiData-API
• OpenData Portal: Feedback to administration

Conflict Handling

Simultaneous Editing

When multiple users edit the same feature:

1. Warning: "Feature is already being edited"
2. Options:
   • Wait until other user is finished
   • Read-only mode
   • Force conflict (for admins)

Version Conflict

In case of version conflicts (server has newer version):

1. Merge Dialog: Shows both versions
2. Comparison: Side-by-side view
3. Resolution:
   • Adopt server version
   • Prefer local version
   • Manual merge

Undo

Before Submission

• Ctrl + Z: Undo single change
• "Discard": Discard all changes of a feature

After Submission

• Only by Admins: Submitted changes can only be reverted by moderators
• Justification Required: Why should the change be reverted?

Offline Mode

p2d2 supports offline editing:

1. Synchronize Data: Before going offline
2. Edit Offline: All functions available
3. Synchronization: Changes are uploaded once online connection exists

Avoid Data Loss

Do not delete browser cache while unsaved changes exist!

Best Practices

• Submit Regularly: Submit changes regularly for QA instead of accumulating large batches
• Comments: Describe your changes meaningfully
• Check Before Submission: Review your work yourself before submitting
• Backup: For extensive changes: Export as GeoJSON for safety