Scenario-based onboarding for iOS

This is a sample implementation of a smart onboarding on iOS. This is the code used for this presentation at CocoaHeads Montpellier (in french).

This sample presents steps to build a simple smart onboarding based on scenarios using events and RxSwift as the event flow handler.

Each steps for building the engine is tagged with the step number. To follow this tutorial, I suggest to open the README on one side of your screen and the Xcode project on the other side.

The goal of this onboarding is to ask the user to enable iCloud to sync its data only after she created some data.

Step 1: creating the project

$ git checkout 00-initial_code

First, we create a new Xcode project with the master/details template provided by Xcode. This project has two controllers and shows a list of dates created by the user, and the details of this date when selected.

We want to create an onboarding engine capable of doing actions at appropriate time and context. A scenario can be represented as a flow of events so let's start by implementing a global event mecanism for our app.

Step 2: event engine

$ git checkout 01-events

Our first implementation of the event system is based on NSNotifications. It is quite simple to implement.

I created an AnalyticsHelper class that contains the events to be emitted (represented by String objects) and added calls to NSNotification.postNotification(_:object:userInfo:) in MasterViewController and DetailsViewController.

I may use my event system to integrate a statistics library (such as Google Analytics). To check my event system works properly, I implement a fake statistics system.

I created a StatsHelper class that register to the AnalyticsHelper events and print the event and its associated data to the console. Run the app, create some dates and navigate to them. You should see these events.

Step 3: some reactivity

$ git checkout 02-reactive_events

So, scenarios are represented as a flow of events, meaning we'll need some ways to retain states to be able to write scenarios like:

Given I am on the master view
When I create a new date
And see that date
And return to the master view
Then I am proposed to enable iCloud

I could stay with NSNotifications and retain states to know if the viewMaster event has been emitted, then the createDetail event, then the viewDetail one. However, this would make very complex code, hard to maintain, especially if I want to add other scenarios.

RxSwift and ReactiveCocoa are two frameworks that can help handle this complexity in a simple way, given you've spent some time learning them (believe me, it's worth it).

In this commit, I updated the code to use RxSwift instead of NSNotifications.

Step 4

$ git checkout 03-reactive_onboarding

From this point, it is really easy to implement our onboarding engine. I just have to use the right Rx operators to combine my events and ask the user to enable iCloud. See the OnboardingHelper class.