Collaboration Features

Implementing multi-user collaboration features: transactions, undo/redo, presence, and conflict handling.

Overview

Beyond basic data synchronization, collaborative applications need features that make the multi-user experience smooth and intuitive. This section covers the key collaboration patterns.

Topics

• Transactions - Batching changes with yDoc.transact()
• Undo/Redo - Per-user undo stacks with UndoManager
• Awareness - Presence, cursors, and user status
• Conflict Resolution - How CRDT merging works

Why These Features Matter

Transactions

Without transactions, each change triggers a separate sync and observer event. This causes:

• Performance issues from excessive network traffic
• Visual flickering as partial changes render
• Undo capturing individual operations instead of logical units

Undo/Redo

Users expect undo to reverse their own changes, not their collaborators’. Proper undo implementation requires:

• Per-user tracking with trackedOrigins
• Integration with transactions for atomic operations
• Cursor restoration for text editing

Awareness

Seeing where other users are working prevents conflicts and enables coordination:

• Cursor positions and selections
• User names and colors
• Typing indicators and active states

Conflict Resolution

Understanding how CRDTs resolve conflicts helps you design structures that merge intuitively:

• Last-writer-wins for simple values
• Character-level merging for text
• Concurrent array insertions