Real-time Applications with MongoDB Atlas

Built with Qt

Integrating Realm with Atlas Device Sync into Qt applications






Most used modern database

Realm is MongoDB's modern data store for mobile and devices. It is simple to use because it is an object database and does not require a separate mapping layer. Updates to the underlying data store are reflected instantly in the objects, which can drive reactive UI layers in different environments. Realm also works together with Atlas Device Sync seamlessly, providing mobile-to-cloud data sync capabilities enabling developers to easily build reactive mobile apps sharing state in real time.

Realm was designed and developed for resource-constrained environments and its C++ SDK is especially well-suited for areas such as embedded devices, IoT, and cross-platform applications. For this reason, MongoDB's team has worked with the Qt Company on an example application showcasing the functionality of Realm with Atlas Device Sync in an IoT scenario. 

Check Qt for Embedded Devices

"The slots and signals mechanism in Qt sits naturally with Realm’s object change listeners. These emit signals of changes to data from Atlas Device Sync so integration is a breeze”

Otso Virtanen, Senior Product Manager, MongoDB

Realm transforms the Qt Coffee Machine app into a fleet of machines

Qt's Coffee Machine demo application demonstrates the clean separation between imperative logic and the purely declarative visual design.

In collaboration with MongoDB's team, Realm and Atlas Device Sync was integrated into Qt Coffee Machine application by extending the existing coffee selection and brewing menu, and by adding local data storage and cloud-syncing—essentially turning the Coffee Machine into a fleet of machines. This fleet can be operated and controlled remotely by an operator and can include separate applications for the field workers maintaining the machines.

Atlas Device Sync makes it easy for developers to build reactive applications for multi-device scenarios by sharing the application state in real time with the cloud and local devices. This is particularly compelling when combined with a powerful GUI framework such as Qt. 

In the Coffee Machine example, MongoDB's team has integrated functionality such as configuring drink recipes in the cloud, out-of-order sensing, and remote control logic. With Realm and Atlas Device Sync, we also get the resiliency for dropped network connections out of the box.

Dive into the source code for the Coffee Machine and the setup instructions to add the same capabilities to your Qt based application.


Realm C++ SDK 

MongoDB just announced the release of the Realm C++ SDK Alpha, and the team continues working towards a Beta. This SDK was built to address the increasing demand – for seamless data management and on-device data storage solutions – from the developer community in industries such as automotive, healthcare, and retail. Look at MongoDB's companion blog post for more details.


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