1.2.0

What's New in 1.2.0

Custom Transaction Merger Support

This release introduces support for custom transaction merger implementations, providing flexibility to handle specific use cases such as undo manager conflicts.

Key Features:

• Public TransactionMergerProtocol: The protocol is now public, allowing developers to create custom merger implementations
• Dependency Injection: Pass custom merger instances via optional merger parameter in initializers
• Crash Prevention: Solves critical crashes when NSManagedObjectContext instances have their undoManager property configured
• Full Backward Compatibility: Existing code continues to work without any changes - defaults to the standard Merger() implementation

Example Usage:

class CustomTransactionMerger: TransactionMergerProtocol {
    func callAsFunction(merge transactions: [NSPersistentHistoryTransaction],
                        into contexts: [NSManagedObjectContext]) {
        for transaction in transactions {
            let notification = transaction.objectIDNotification()
            for context in contexts {
                context.perform {
                    // Temporarily disable undo manager to prevent crashes
                    let undoManager = context.undoManager
                    context.undoManager = nil
                    context.mergeChanges(fromContextDidSave: notification)
                    context.undoManager = undoManager
                }
            }
        }
    }
}

// Use custom merger
let kit = PersistentHistoryTrackingKit(
    // ... other parameters
    merger: CustomTransactionMerger()
)

Credits

Special thanks to @yangyubo for this excellent contribution! This enhancement provides the flexibility needed to handle complex undo manager scenarios while maintaining the simplicity of the default behavior.

Technical Details

• Follows SOLID principles (Open/Closed Principle)
• Improves testability through dependency injection
• All changes are additive with no breaking changes to the public API

Full Changelog: 1.1.0...1.2.0