Custom Conflict Resolution

Custom Conflict Resolution for PocketSync

For applications with specific requirements, PocketSync allows implementing custom conflict resolution logic:

• Set the conflict strategy to ConflictResolutionStrategy.custom
• Provide a custom resolver function that implements the ConflictResolver type
• The resolver receives both conflicting changes and must return the winning change

To use a custom conflict resolver, you must:

• Set the conflictResolutionStrategy to ConflictResolutionStrategy.custom in PocketSyncOptions
• Provide your custom resolver function in the customResolver parameter

Example configuration:

final pocketSync = await PocketSync.initialize(
  options: PocketSyncOptions(
    conflictStrategy: ConflictResolutionStrategy.custom,
    conflictResolver: (localChange, remoteChange) async {
      // Custom logic to determine the winning change
      if (localChange.tableName == 'priorities') {
        return localChange; // Local changes always win for the 'priorities' table
      } else {
        return remoteChange; // Server changes win for other tables
      }
    },
  ),
  // ... other configuration options
);

Custom Conflict Resolver

The custom conflict resolver function receives two parameters:

Parameter	Description
localChange	The local change that conflicts with the remote change
remoteChange	The remote change that conflicts with the local change

The resolver must return the winning change.

Example

final pocketSync = await PocketSync.initialize(
  options: PocketSyncOptions(
    conflictStrategy: ConflictResolutionStrategy.custom,
    conflictResolver: (localChange, remoteChange) async {
      // Custom logic to determine the winning change
      if (localChange.tableName == 'priorities') {
        return localChange; // Local changes always win for the 'priorities' table
      } else {
        return remoteChange; // Server changes win for other tables
      }
    },
  ),
  // ... other configuration options
);

The change object has the following properties:

Property	Type	Description
id	String	Unique identifier for the change
tableName	String	Name of the table being modified
recordId	String	ID of the record being modified
operation	ChangeType	Type of operation (insert, update, delete)
timestamp	int	When the change occurred (milliseconds since epoch)
version	int	Version number of the change
synced	bool	Whether the change has been synced to the server
data	Map<String, dynamic>	The actual data changes for the record

Import note: The data property should always contain a “old” and “new” key. This is needed to maintain consistency with the default conflict resolution strategy.

Conflict Resolution Process