Stream Data to Atlas - React Native SDK

Define an Asymmetric Object

Asymmetric objects sync data unidirectionally. Define an asymmetric object by setting asymmetric to true in your object model:

For more information on how to define an asymmetric object, refer to Define an Asymmetric Object.

Connect and Authenticate with an App Services App

To stream data from the client to your backend App, you must connect to an App Services backend and authenticate a user.

function LogIn() {
  const app = useApp();
  useEffect(() => {
    app.logIn(Realm.Credentials.anonymous());
  }, []);
  return <></>;
}

Data Ingest is a feature of Flexible Sync, so the App you connect to must use Flexible Sync.

Open a Realm

After you have an authenticated user, you can open a synced realm using a Flexible Sync configuration object.

Unlike bi-directional Sync, Data Ingest does not use a Flexible Sync subscription.

You cannot query an asymmetric object or write it to a local realm, so asymmetric objects are incompatible with bi-directional Flexible Sync, Partition-Based Sync, or local Realm use.

Create Asymmetric Objects

Once you have an open Realm, you can create an asymmetric object inside a write transaction using Realm.create(). When creating an asymmetric object, Realm.create() returns undefined rather than the object itself.

const App = () => {
  // Getting access to our opened realm instance
  const realm = useRealm();
  const handleAddSensor = () => {
    realm.write(() => {
      realm.create('WeatherSensor', {
        _id: weatherSensorPrimaryKey,
        deviceId: 'WX1278UIT',
        temperatureInFahrenheit: 66.7,
        barometricPressureInHg: 29.65,
        windSpeedInMph: 2,
      });
    });
  };
  return (
    <Button
      title='Add A New Sensor'
      onPress={() => handleAddSensor()}
    />
  );
};

You cannot read these objects. Once created, they sync to the App Services backend and the linked Atlas database.

Atlas Device Sync completely manages the lifecycle of this data. It is maintained on the device until Data Ingest synchronization is complete, and then removed from the device.