Satori Fitness Demo

The Satori platform transfers large amounts of live data at high speed. It uses a publish/subscribe model: Apps publish data as messages to channels. Apps also subscribe to channels so they can listen for messages and retrieve them when they arrive. Based on WebSocket, the platform transfers messages of almost any size with almost no delay.

To publish to channels, subscribe to channels, and retrieve data, you use the high-level Satori RTM SDK API libraries. For special cases, Satori also offers a low-level library called the RTM API.

The Satori platform also provides ways to customize messages:

• Streambots subscribe to a channel and execute custom code on each incoming message. You create streambots in Java.
• Streamviews select, transform, or aggregate messages from a subscribed channel based on criteria you define in Stream SQL, a Satori variant of SQL.

RealFitness apps

The Satori RealFitness demo apps for Apple Watch and iPhone use the Satori platform to implement a simple workout tracker:

• To see a demo of the apps, follow the steps in the section Run the demo.
• To learn how the apps work, see the section App overview.

Run the demo

You can run the demo apps locally, either on devices or in Xcode simulators. Satori provides the source files for the apps on GitHub.

Note: Unlike other Satori demo apps, the fitness demo doesn't have an online version.

The source includes:

• Objective-C code for the iPhone and the Apple Watch apps
• Build files for Xcode
• Configuration files for 3rd-party frameworks
• Satori API libraries

Prerequisites

To build and run the demo apps, you need:

• Xcode 8.3.3 or later
• The Carthage framework manager for Cocoa:
  • The section "Installing Carthage" on the repo home page lists the installation options.
  • The 3rd-party frameworks you need are already configured in the source. Carthage uses the configuration to build and install the frameworks.
• An iPhone simulator or iPhone with iOS 10.0 or later.
• An Apple Watch simulator or Apple Watch Series 2 with WatchOS 3.1 or later.

Notes:

• To run the demo on devices, you need an Apple Developer License linked to Xcode.
• The demo app UI is optimized for iPhone 6, 6s, 7 and 7s.
• The watch app works only on a 42mm Apple Watch Series 2 or equivalent simulator.

Create the apps

Get credentials from Satori

To use the Satori platform, you need a Satori account and project:

1. Get for a Satori account at https://developer.satori.com. If you already have an account, just sign in.
2. From the dashboard, navigate to the Projects page.
3. Click Add a project, then enter the name "fitness" and click Add.
4. Satori displays an appkey and endpoint for your project. These credentials let the apps connect with Satori. Make a copy of them.
5. Click Save to save the project.

Get the source

Clone the demo source files from GitHub:

git clone [email protected]:satori-com/fitness.git
cd fitness

Build the apps

1. Run carthage update to build and install the 3rd party frameworks used by the apps.
2. In Finder, double-click RealFitness.xcodeproj to open the demo app project in Xcode.
3. In Xcode Project Navigator, edit RealFitness > Constants.h and replace YOUR_ENDPOINT and YOUR_APPKEY with the values you copied from your Satori project page.
4. In Xcode, build the RealFitness scheme.

Start the apps

Start the apps on devices

1. Install the apps on your hardware.
   • For an optimum experience, use an iPhone 6, 6s, 7 or 7s.
   • The Apple Watch must be a 42mm Series 2.
2. On your Apple Watch, click the Home button, then click the RealFitness icon to open the app.
3. On your iPhone, open the RealFitness app.

Start the apps in simulators

1. To get the best UI experience, set up Xcode to use an iPhone 6, 6s, 7 or 7s simulator.
2. Ensure that you pair the iPhone simulator with an Apple Watch Series 2 42mm simulator.
3. In Xcode, run the demo using your simulator scheme. When you first run the apps, the simulators may take a few seconds to start.

Use the apps

1. In the watch app, click one of the goals to see your heart rate (the simulator version displays a simulated rate).
2. The RealFitness iPhone app displays the data from the watch app.
3. Click Social at the bottom of the iPhone app. The new screen displays all active users and their workout data. In the demo, you're the only active user.
4. Click on your name on the Social page to see the My Activity page.

App overview

Watch app

• RealFitness for the Apple Watch retrieves heart rate and other workout data from the Apple HealthKit framework.
• In the app, users choose a workout goal. For that goal, the app sets a target heart rate zone.
• The watch app sends the workout goal and workout data to the iPhone the watch is linked to.
• The watch app also displays heart rate, workout goal, and performance to target on its main screen. Users can swipe to the right-hand screen to see more detailed data.
• Users can stop their workout by swiping to the left-hand screen and clicking Stop run.

iPhone app

• RealFitness for iPhone receives the workout goal and workout data from the watch app. It displays this information on its main screen, which also shows an animated runner that moves faster or slower depending on the user's performance to goal.
• The app publishes messages containing the workout data to a channel. It subscribes to the same channel, so it can display workout data from messages send by other app users who are currently working out (the active users).
• Active users can also send reaction messages to each other in a separate channel.

The Satori fitness demo app uses the following frameworks and APIs:

• Apple HealthKit Framework
• Apple WatchKit Framework
• iOS Wrapper for Satori C SDK

iPhone app details

Channels

• The app publishes workout data to a channel called Fitness. It also subscribes to this channel, so that the app instance for each active user can retrieve and display results from other active users.
• The app also publishes reaction messages. Each app instance has its own unique userId value, which it uses to create a userId-Reactions channel. To send a reaction message to another user, the app instance publishes it to the appropriate userId-Reactions channel. Reaction messages let active users encourage each other with emoticons.

Streamiews

Streamviews (formerly called Filters) filter and aggregate incoming messages that an app is subscribed to.

userId streamview

The app subscribes to the Fitness channel using a streamview that selects messages that have the user's userId. This lets the app filter out its own messages when it displays workout data on the Social screen.

Aggregation streamview

The app also uses an aggregation streamview to manage the data rate in the channel. The iPhone app publishes live data to the Fitness channel every few milliseconds, so other app instances can receive a large number of messages every second.

If the iPhone app tried to update the Social screen many times a second, the UI could lose responsiveness. To keep the UI fluid, the iPhone app uses a streamview to aggregate messages.

When the app subscribes to the Fitness channel, it selects a streamview "period" of 1 second. Message values are averaged over a period of 1 second before the iPhone app receives them from the channel.

To learn more about aggregation, see the section Aggregate Views in the Satori Docs topic Views.

Next steps

The RealFitness apps demonstrate the following tasks:

• Building a WatchOS app based on Apple HealthKit
• Sending data from an Apple Watch to an iPhone
• Publishing, subscribing to, and retrieving live data in an iPhone app using the Satori platform
• Selecting and aggregating messages using streamviews.

Try extending the apps. Here are some ideas:

• Extend the functionality of the apps to track even more workout statistics such as step count or cycling distance.
• Build a health tracker by adding other compatible biometric data collection devices that let health care providers track patient health remotely.

Further reading

• Satori Developer Documentation: Documentation for the entire Satori platform
• Satori C SDK: The Satori C RTM SDK that accesses the Satori platform