Custom Conflict Resolution

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.

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Custom Conflict Resolution

Custom Conflict Resolver

Example

Conflict Resolution Process

​Custom Conflict Resolver

​Example

​Conflict Resolution Process

Custom Conflict Resolver

Example

Conflict Resolution Process