iOS 16 beta 4 is the primary SDK launch that helps Reside Actions. A Reside Exercise is a widget-like view an app can place in your lock display and replace in actual time. Examples the place this may be helpful embrace dwell sports activities scores or prepare departure occasions.
These are my notes on taking part in with the API and implementing my first Reside Exercise.
A motorbike laptop in your lock display
My Reside Exercise is a show for a motorcycle laptop that I’ve been growing with a gaggle a pals. Right here’s a video of it in motion:
And right here with simulated information:
I haven’t talked a lot about our bike laptop mission publicly but; that may hopefully change sometime. In brief, a gaggle of pals and I designed a bit field that connects to your bike’s hub dynamo, measures velocity and distance, and sends the information by way of Bluetooth to an iOS app. The app data all of your rides and can even act as a dwell speedometer when mounted in your bike’s handlebar. It’s this final characteristic that I needed to copy within the Reside Exercise.
Observe Apple’s information
Including a Reside Exercise to the app wasn’t laborious. I discovered Apple’s information Displaying dwell information on the Lock Display with Reside Actions simple to observe and fairly complete.
No express consumer approval
iOS doesn’t ask the consumer for approval when an app needs to point out a Reside Exercise. I discovered this odd because it appears to ask builders to abuse the characteristic, however possibly it’s OK due to the foreground requirement (see under). Plus, customers can disallow Reside Actions on a per-app foundation in Settings.
Customers can dismiss an lively Reside Exercise from the lock display by swiping (like a notification).
Most apps will in all probability must ask the consumer for notification permissions to replace their Reside Actions.
The app have to be within the foreground to start out an exercise
To start out a Reside Exercise, an app have to be open within the foreground. This isn’t perfect for the bike laptop as a result of the speedometer can’t seem magically on the lock display when the consumer begins using (though iOS wakes up the app within the background at this level to ship the Bluetooth occasions from the bike). The consumer has to open the app manually at the least as soon as.
Then again, this limitation will not be a problem for many use circumstances and can in all probability reduce down on spamming/abuse considerably.
The app should hold working within the background to replace the exercise (or use push notifications)
So long as the app retains working (within the foreground or background), it will possibly replace the Reside Exercise as typically because it needs (I feel). That is perfect for the bike laptop because the app retains working within the background processing Bluetooth occasions whereas the bike is in movement. I assume the identical applies to different apps that may stay alive within the background, similar to audio gamers or navigation apps doing steady location monitoring.
Updating the Reside Exercise as soon as per second was no drawback in my testing, and I didn’t expertise any fee limiting.
Most apps get suspended within the background, nonetheless. They need to use push notifications to replace their Reside Exercise (or background duties or another mechanism to have the system wake you up). Apple launched a brand new type of push notification that’s delivered on to the Reside Exercise, bypassing the app altogether. I haven’t performed with push notification updates, so I don’t know the advantages of utilizing this methodology over sending a silent push notification to wake the app and updating the Reside Exercise from there. Most likely much less aggressive fee limiting?
Lock display colour matching
I haven’t discovered a great way to match my Reside Exercise’s colours to the present system colours on the lock display. By default, textual content in a Reside Exercise is black in gentle mode, whereas the built-in lock display themes appear to favor white or different gentle textual content colours. If there’s an API or surroundings worth that enables apps to match the colour fashion of the present lock display, I haven’t discovered it. I experimented with varied foreground types, similar to supplies, with out success.
I ended up hardcoding the foreground colour, however I’m not happy with the end result. Relying on the consumer’s lock display theme, the Reside Exercise can look misplaced.
Animations can’t be disabled
Apple’s information clearly states that builders have little management over animations in a Reside Exercise:
Animate content material updates
Once you outline the consumer interface of your Reside Exercise, the system ignores any animation modifiers — for instance,
withAnimation(_:_:)andanimation(_:worth:)— and makes use of the system’s animation timing as an alternative. Nevertheless, the system performs some animation when the dynamic content material of the Reside Exercise modifications. Textual content views animate content material modifications with blurred content material transitions, and the system animates content material transitions for photos and SF Symbols. If you happen to add or take away views from the consumer interface primarily based on content material or state modifications, views fade out and in. Use the next view transitions to configure these built-in transitions:opacity,transfer(edge:),slide,push(from:), or mixtures of them. Moreover, request animations for timer textual content withnumericText(countsDown:).
It makes complete sense to me that Apple doesn’t need builders to go loopy with animations on the lock display, and maybe having full management over animations additionally makes it simpler for Apple to combine Reside Actions into the always-on show that’s in all probability approaching the subsequent iPhone.
What shocked me is that I couldn’t discover a solution to disable the textual content change animations altogether. I discover the blurred textual content transitions for the big velocity worth fairly distracting and I feel this label would look higher with none animations. However no mixture of .animation(nil), .contentTransition(.id), and .transition(.id) would do that.
A Reside Exercise may be very very like a widget: the UI should dwell in your app’s widget extension. You begin the Reside Exercise with code that runs in your app, although. Each targets (the app and the widget extension) want entry to a typical information sort that represents the information the widget shows. You need to have a 3rd goal (a framework or SwiftPM package deal) that accommodates such shared varieties and APIs and that the downstream targets import.
Availability annotations
WidgetBundle apparently doesn’t help widgets with completely different minimal deployment targets. In case your widget extension has a deployment goal of iOS 14 or 15 for an present widget and also you now need to add a Reside Exercise, I’d anticipate your widget bundle to appear like this:
@predominant
struct MyWidgets: WidgetBundle {
var physique: some Widget {
MyNormalWidget()
// Error: Closure containing management circulate assertion can't
// be used with end result builder 'WidgetBundleBuilder'
if #out there(iOSApplicationExtension 16.0, *) {
MyLiveActivityWidget()
}
}
}
However this doesn’t compile as a result of the end result builder sort utilized by WidgetBundle doesn’t help availability circumstances. I hope Apple fixes this.
This wasn’t an issue for me as a result of our app didn’t have any widgets till now, so I simply set the deployment goal of the widget extension to iOS 16.0. You probably have present widgets and might’t require iOS 16 but, a workaround is so as to add a second widget extension goal only for the Reside Exercise. I haven’t tried this, however WidgetKit explicitly helps having a number of widget extensions, so it ought to work:
Sometimes, you embrace all of your widgets in a single widget extension, though your app can comprise a number of extensions.
