How to customize Apple CareKit?

Question

In CareKit there are Care Card and Symptom tracker. I'm not understanding how to customize Carecardviewcontroller and symptomtrackerviewcontroller. I don't want to use these view controllers but interested in using components of these view controllers. there is no clear documentation to explore this.

_{(source: carekit.org)}

Answer 1

I've been looking for this answer myself.

As far as I researched, you can customize this screen visually with UIAppearance. AND/OR you can create a new screen like this one from scratch using its behavior.

You can check the CareKit source code for hints on this: https://github.com/carekit-apple/CareKit/tree/master/CareKit/CareCard

There you'll notice some interesting classes/files:

• OCKCareCardWeekView
• OCKWeekLabelsView
• OCKHeartView
• OCKHeartButton
• OCKWeekViewController
• OCKHelpers

CareKit draws each screen via code. You can see how they do it by reading the code. The idea is to create your own ViewController with these pieces, or one from scratch.

Surely it's not as trivial as just using CareCardViewController, but this will get you there.

Answer 2

If you are coming at this from a Swift perspective, then it has to be admitted that CareKit is about as "un-Swifty" as anything you can imagine. The GitHub site is certainly a start, but there is a horrific gap between reading the programming guides there and actually implementing a solution. It certainly has been a long slog for me!

That said, you can add customization to CareKit's story-board-free approach by using the view controller delegate functions that CareKit provides.

For example, suppose you have an app that reminds your user to perform two intervention activities, (1) take aspirin and (2) go for a brisk walk. If the user opens the Care Card and taps an event icon (one of the circles) for "take aspirin" then that will fire a method in the OCKCareCardViewControllerDelegate called:

careCardViewController(_ viewController: OCKCareCardViewController,
                       didSelectButtonWithInterventionEvent: OCKCarePlanEvent)

In this method you can segue to whatever view controller you'd like. E.g. if the event is for taking aspirin then display a view controller that shows a photo of an aspirin table, a reminder that it should contain just an 81 mg dose, and a recommendation about taking it with water.

Of course, nothing is ever easy with CareKit. It turns out that you will probably also want to turn off CareKit's standard practice of calling an event completed if the circle icon is tapped. That is accomplished by returning "false" from another delegate method called:

careCardViewController( _ viewController: OCKCareCardViewController,
                        shouldHandleEventCompletionFor
                            interventionActivity: OCKCarePlanActivity )
                      -> Bool

There is a book called Beginning CareKit Development that I can cautiously recommend. It was written for an earlier version of Swift and you have to do a lot of "translation" to get things to work with Swift 3. The last time I checked the GitHub repository for the code associated with the book was also entirely in this earlier version. APress will provide the code updated to Swift 3 if you ask. On the Kindle there are numerous little glitches with the book, including an index that has no page numbers nor hyperlinks to the associated text, very odd formatting choices that make the text sometimes hard to distinguish from code, and occasional errors in the solution code. All that said, I doubt that I'd have made any progress with CareKit without the book's help.