NETCoreSync

NETCoreSync is a database synchronization framework where each client's local offline database (on each client's multiple devices) can be synchronized on-demand via network into a single centralized database hosted on a server. Data which are stored locally within each device of a single client can all be synchronized after each device have successfully performed the synchronization operation.

This framework has two components that needs to be implemented in each of your client and server projects, and this framework has two versions that is determined by how you've built your client projects.

Flutter Version

Client	Client Generator	Server

If the client is built using Flutter, use the Flutter version of NETCoreSync. This version provides netcoresync_moor package for the client side, and the NETCorSyncServer package for the server side. The client's netcoresync_moor package is built on top of Flutter's Moor library, and the server's NETCoreSyncServer package is built using Microsoft .NET 5.0 ASP .NET Core Middleware.

Repository Folders

The repository folders are

• netcoresync_moor: Client-side Flutter package
• netcoresync_moor_generator: Client-side Flutter code generator
• NETCoreSyncServer: Server-side .NET 5.0 Middleware package
• Samples/ServerTimeStamp/clientsample: Client-side Flutter project example
• Samples/ServerTimeStamp/WebSample: Server-side .NET 5.0 ASP Core project example

Xamarin Version

Client + Server

If the client is built using Xamarin, use the Xamarin version of NETCoreSync. This version provides NETCoreSync package for both client and server side. The NETCoreSync package is built using Microsoft .NET Standard 2.0.

Repository Folders

The repository folders are

• NETCoreSync: Client-side and Server-side .NET Standard 2.0 package
• Samples/GlobalTimeStamp: Client-side Xamarin and Server-Side .NET Core 3.1 project example for the GlobalTimeStamp synchronization approach
• Samples/DatabaseTimeStamp: Client-side Xamarin and Server-Side .NET Core 3.1 project example for the DatabaseTimeStamp synchronization approach

Characteristics

The following lists the characteristics of this framework (applies for both Flutter and Xamarin versions):

• It's database-agnostic, means, it can be used with any kind of database technology, as long as you can direct it (technically by subclassing its engine) to the correct implementation on how to do this-and-that in your specific database.
  • For Flutter version, the client side framework is built on top of Moor and will use any database that is configured with it, so therefore the client side is not database-agnostic, while the server side framework is still database-agnostic.
  • For Xamarin version, the client and server side framework are fully database-agnostic.
• Not like other synchronization frameworks, NETCoreSync doesn't use tracking tables and tombstone tables (I hate them, because most likely they will double up your row count and take storage space), but, you need to add some additional columns to your tables.
• Not like other synchronization frameworks, NETCoreSync doesn't use triggers (I also hate triggers, because not all database technology support triggers, and it always feels like I have some unused left-over triggers somewhere in my tables...), but, you have to modify your application's insert/update/delete data functions.
  • For Flutter version, you will have to change the standard calls to Moor's insert/update/delete methods in the client project into this framework ones.
  • For Xamarin version, you have to call some hook methods in the client project before persisting the data into the table.
• This framework requires that all of your data in your database to have a unique primary key.
  • For Flutter version, your Moor table's primary key is expected to be a TextColumn type and should contain unique Uuid values (probably generated from the uuid package).
  • For Xamarin version, the type of your table's primary key is not enforced to a specific data type, but commonly it should use Guid values (and therefore the table's column type is usually a string) to ensure its uniqueness.
• Your database design must use the Soft Delete approach when deleting record from tables, means that for any delete operation, the data is not physically deleted from the table, but only flag the record with a boolean column that indicates whether this record is already deleted or not.

Version Comparison

The Flutter version is actually newer than the Xamarin version (the Xamarin version was the initial framework when NETCoreSync was built). Flutter has become one of the hottest framework nowadays to easily build a beautiful, performant, single code-base application that works on ALL platforms (android, ios, web, windows, macos, linux), so naturally, NETCoreSync is adapted to work with Flutter. There are several advantages of the Flutter version:

• The Flutter version has a feature called "linkedSyncId" where a single user account can be linked with several different user accounts to allow them to share data among themselves (they can modify each other data), and those changes can still be synchronized back to each user account devices.
• The client-side component for Flutter version (which is built on top of Moor library) has much less integration work compared to the Xamarin version, so it requires only minimal modification on the client project. Of course this makes the client project depended on the Moor library, but by doing this, the integration is very minimal, and Moor itself is considered as one of the leading sqlite database framework for Flutter.
• The server-side component for Flutter version has been rewritten using the latest .NET 5.0 (as per writing), and also rewritten to use WebSockets to allow efficient network communication, and implemented as an ASP .NET Core Middleware component to also minimize the integration work.

Moving forward, the Flutter version will be the primary development to have periodical updates and improvements, while the Xamarin version will remain as a backward-compatible solution only.

To read more about the Flutter version of NETCoreSync, visit the netcoresync_moor here.

To read more about the Xamarin version of NETCoreSync, visit the NETCoreSync here.