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 screen and replace in actual time. Examples the place this may be helpful embrace reside sports activities scores or practice departure instances.
These are my notes on enjoying with the API and implementing my first Reside Exercise.
A motorcycle laptop in your lock display screen
My Reside Exercise is a show for a motorcycle laptop that I’ve been creating with a bunch a mates. Right here’s a video of it in motion:
And right here with simulated knowledge:
I haven’t talked a lot about our bike laptop venture publicly but; that may hopefully change sometime. Briefly, a bunch of mates and I designed somewhat field that connects to your bike’s hub dynamo, measures pace and distance, and sends the information through Bluetooth to an iOS app. The app information all of your rides and may also act as a reside speedometer when mounted in your bike’s handlebar. It’s this final characteristic that I wished to duplicate within the Reside Exercise.
Comply with Apple’s information
Including a Reside Exercise to the app wasn’t arduous. I discovered Apple’s information Displaying reside knowledge on the Lock Display with Reside Actions straightforward to comply with and fairly complete.
No specific person approval
iOS doesn’t ask the person for approval when an app desires to indicate 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 energetic Reside Exercise from the lock display screen by swiping (like a notification).
Most apps will most likely have to ask the person for notification permissions to replace their Reside Actions.
The app have to be within the foreground to begin an exercise
To start out a Reside Exercise, an app have to be open within the foreground. This isn’t excellent for the bike laptop as a result of the speedometer can’t seem magically on the lock display screen when the person begins driving (though iOS wakes up the app within the background at this level to ship the Bluetooth occasions from the bike). The person has to open the app manually a minimum of as soon as.
However, this limitation will not be a difficulty for many use circumstances and can most likely lower down on spamming/abuse considerably.
The app should maintain operating within the background to replace the exercise (or use push notifications)
So long as the app retains operating (within the foreground or background), it may well replace the Reside Exercise as usually because it desires (I feel). That is excellent for the bike laptop because the app retains operating 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, equivalent to audio gamers or navigation apps doing steady location monitoring.
Updating the Reside Exercise as soon as per second was no downside in my testing, and I didn’t expertise any charge limiting.
Most apps get suspended within the background, nonetheless. They have 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 sort 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. In all probability much less aggressive charge limiting?
Lock display screen coloration matching
I haven’t discovered a great way to match my Reside Exercise’s colours to the present system colours on the lock display screen. By default, textual content in a Reside Exercise is black in gentle mode, whereas the built-in lock display screen themes appear to favor white or different gentle textual content colours. If there’s an API or setting worth that enables apps to match the colour fashion of the present lock display screen, I haven’t discovered it. I experimented with varied foreground types, equivalent to supplies, with out success.
I ended up hardcoding the foreground coloration, however I’m not happy with the consequence. Relying on the person’s lock display screen 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 person 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. Nonetheless, the system performs some animation when the dynamic content material of the Reside Exercise adjustments. Textual content views animate content material adjustments with blurred content material transitions, and the system animates content material transitions for photographs and SF Symbols. For those who add or take away views from the person interface based mostly on content material or state adjustments, views fade out and in. Use the next view transitions to configure these built-in transitions:opacity,transfer(edge:),slide,push(from:), or combos of them. Moreover, request animations for timer textual content withnumericText(countsDown:).
It makes whole sense to me that Apple doesn’t need builders to go loopy with animations on the lock display screen, and maybe having full management over animations additionally makes it simpler for Apple to combine Reside Actions into the always-on show that’s most likely approaching the following iPhone.
What shocked me is that I couldn’t discover a technique to disable the textual content change animations altogether. I discover the blurred textual content transitions for the massive pace 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 could be very very like a widget: the UI should reside 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 knowledge kind that represents the information the widget shows. You must have a 3rd goal (a framework or SwiftPM package deal) that comprises 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 current widget and also you now wish to add a Reside Exercise, I’d anticipate your widget bundle to appear to be this:
@predominant
struct MyWidgets: WidgetBundle {
var physique: some Widget {
MyNormalWidget()
// Error: Closure containing management circulate assertion can not
// be used with consequence builder 'WidgetBundleBuilder'
if #out there(iOSApplicationExtension 16.0, *) {
MyLiveActivityWidget()
}
}
}
However this doesn’t compile as a result of the consequence builder kind utilized by WidgetBundle doesn’t help availability situations. 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. If in case you have current widgets and may’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.
