RT Streaming - iOS

TerraRTiOS

This packages uses Bluetooth Low Energy (BLE) and Bluetooth services. These will be requested as permissions upon initialisation of the package.

The package streams real time data to your backend through WebSockets. You can learn more about it at the Terra WebSocket API guide.

The data streamed to your WebSocket connection will follow the following format:

{
  "op":5,
  "d":
    {
      "ts": <String> (In ISOFormat Date Form)
       "val": <Double>
       "d" <Array<Double>>
    },
    "uid": <String> (user ID)
    "seq": <Int>,
    "t": <String> (Datatype name: Exactly the same as the name of `DataTypes` enum)
}

ts is the timestamp of the record. For each datatype, either val or d is populated. See the Terra Streaming Protocol Reference for full details about the payload format.

Installation

You can use Swift Package Manager and add this github repo as a dependency to your project! Add the SDK to your app as a dependency by following these steps:

  1. Enrol in the Apple Developer Programme:
    https://developer.apple.com/programs/enroll/

  2. Download our SDK:
    https://github.com/tryterra/TerraRTiOS.git

  3. Open your project in Xcode.

  4. Add SDK to Package Dependencies:
    Go to main app folder > click on icon below PROJECT on sidebar > click on Package Dependencies on menu bar > click on + button under Packages table > click on + button at bottom left of pop up > click on Add Local... > select TerraRTiOS folder and click Add Package

  5. Add Privacy Keys:
    The SDK requires Bluetooth to function, and the user will need to give explicit permission for your app to access the Bluetooth functionality on their device. To facilitate this:

    Go to main app folder > click on the icon below TARGETS on the sidebar > click on Info on menu bar > go to Custom iOS Target Properties > hover over any key and click + button > add Privacy - Bluetooth Always Usage Description. If you wish to use Connections.APPLE connection, also add Privacy - Motion Usage Description.

    Your app will now request the user to give all the correct permissions (only happens once, on the first time launching the app after install).

Usage

The package is controlled mainly by a class called TerraRT

You may initialise as such:

import TerraRTiOS

terraRT = TerraRT()

After the initialisation, you may now start initialising different connections! This can be done as:

terraRT.initConnection(token: String, type: Connections)

Arguments

  • token: String -> A Mobile SDK token generated from the Mobile SDK Token endpoint.
  • completion: (Bool) -> Void -> A completion function that is called when the initialisation is complete.

Connecting Bluetooth

Certain types of connection will require a Bluetooth Connection (Connections.BLE). To initialise a bluetooth connection, you can run:

let terraBLEWidget: TerraBLEWidget = terraRT.startBluetoothScan(type: Connections, callback: @escaping (Bool) -> Void)

Arguments

  • type: Connections -> An Enum signifying the connection to make.
  • callback: @escaping (Bool) -> Void -> A callback that will be called with true if the connection is successful and false if the connection is unsuccessful.

This will return a SwiftUI View! You can then display this to your user, and have them scan, and connect to a BLE Device!

Data Streaming πŸ”₯πŸ”₯

Each streaming session requires a token for authentication to Websocket API. This can be generated from the Streaming User Token endpoint. Note: this is a different token from the Mobile SDK token used earlier. The request requires the following fields:

  • dev_id - found at your Terra Dashboard
  • x_api_key - found at your Terra Dashboard
  • user_id - the user_id of the connection you wish to stream

Get the user_id of the current connection as such:

terraRT.getUserId()

You can now start streaming! This is done using:

terraRT.startRealtime(type: Connections, token: String, dataType: Set<DataTypes>)

Arguments

  • type: Connections -> An Enum signifying the connection to make.
  • token: String -> A Streaming User Token for authentication to Websocket API. This can be generated from the Streaming User Token endpoint
  • dataType: Set -> A set of Enums signifying the datatypes you wish to stream. Note if the data type is not supported by the type Connections, then it will simply return!

You may stop the streaming as follows:

terraRT.stopRealtime(type: Connections) 

And also disconnect from the connection as follows:

terraRT.disconnect(type: Connections)

WatchOS [New Feature! From TerraRTiOS 0.1.1]

TerraRTiOS Framework supports streaming from Apple Watch as well!

Your iOS app will have to be coupled with the Watch App. This means within your iOS project, you will need to create a target to WatchOS App:

File -> New -> Target -> Watch App for iOS App.

This will generate a new app for Watch OS within the same project.

Within this app, you can add TerraRTiOS as a framework and build the app with it.

Setup

The WatchOS will require HealthKit and Background Modes Capabilities with background delivery and workout processing enabled.

You will also need to add 3 Keys to the Info.plist file with descriptions on how you will use Health Kit's data:

  • Privacy - Health Share Usage Description
  • Privacy - Health Update Usage Description
  • Privacy - Health Records Usage Description

Get Started

This half of the SDK contains functions that can only be imported from WatchOS apps. You can access these by having import TerraRTiOS on top of your file within the WatchOS App.

The Terra class here manages everything. Always Initialise one:

let terra: Terra = try? Terra()

This function can throw: TerraWatchOSErrors.WatchOSConnectioNotSupported, TerraWatchOSErrors.HealthKitNotSupported. Please catch and handle appropriately.

Upon start of the app, make sure the watch is paired to the phone.

From the phone app, run the following to initiate a connection to the paired watch:

// Where terraRT is the TerraRT(..) class from iOS App
try? terraRT.connectWithWatchOS()

This function will throw an error TerraError.FeatureNotSupported if watch connectivity is not supported on the current device.

When the companion app is installed on the Watch, this call will create a connection with the Watch.

If the watch failed to connect to the device or you wish to connect to a separate watch, on the watch you may also try to activate a session by:

terra.connect()

Streaming

N.B: For WatchOS Streaming, the datatypes being streamed are controlled entirely by the Watch App. On the iOS app, you will simply have to accept data through terraRT.startRealtime(...)

On the Watch App, you can start streaming data straight away to your iOS App from the sensors as:

terra.startStream( forDataTypes dTypes: Set<ReadTypes>, completion: @escaping(Bool) -> Void)

Workouts

The Watch App can stream workout details to your iOS app!

Simply start by

startExercise(forType workoutType: WorkoutTypes, completion: @escaping (Bool) -> Void)

You may also, stop, resume, and pause as such:

stopExercise(completion: @escaping (Bool) -> Void)
resumeExercise()
pauseExercise()