Introduction to Data Synchronization

The @graphback/datasync package consists of the Data Synchronization Schema plugin and compatible data sources, provides out of the box Data Synchronization strategies for GraphQL clients with offline functionality e.g. Offix.

note

Currently this plugin only supports MongoDB data sources, with support for other kinds of data sources coming in a future release.

Motivation

The @graphback/datasync package is meant to be naturally extend Offix with a GraphQLCRUD compliant API:

• Fetch data that was changed based on the client side timestamp
• Ensure data consistency using timestamp provided

It achieves this by:

• Providing Delta Queries: Delta queries can be used by GraphQL clients to refresh changes in data between periods of connectivity outages.
• Providing server-side Conflict Resolution capabilities: For mutations that are applied offline, this provides the server with the ability to resolve conflicts between server and client.

Installation

The Graphback Data Synchronization package provides schema plugins as well as data sources for all supported data synchronization features.

npm install @graphback/datasync

Usage

In order to use data synchronization features, there are two steps to be followed:

• Add metadata to schema
• Use createDataSyncAPI to create the API using Graphback

For a more in-depth guide to setting up data synchronization features, check this page.