Forcing update to placeholder complication on Apple Watch - swift

Question

Here a simple issue I am facing while starting to experiment with WatchKit and complications.
I created a simple app which is showing a complication with a public string “Y” and by clicking it, the Apple Watch app is shown with a simple switch.
I wrote my code in getPlaceholderTemplateForComplication in ComplicationController.swift and added a switch IBAction in InterfaceController.swift.
By changing the value of the switch, the public string cycles between “N” and “Y”. I would like to have it changed in the complication as well. However I am noticing that the complication stays as it is initially at “Y”.
I found a similar question about forcing complication updates, but it was related to a TimeLine complication func and not placeHolder.
func updateComplication() {
let complicationServer = CLKComplicationServer.sharedInstance()
for complication in complicationServer.activeComplications {
complicationServer.reloadTimelineForComplication(complication)
}
}
It is not clear to me on where and how to use this in my case.
As suggested I worked on getCurrentTimelineEntryForComplication .
In order to test a ModularComplication only, I used:
switch complication.family {
case .ModularSmall:
let modularSmallTemplate =
CLKComplicationTemplateModularSmallRingText()
modularSmallTemplate.textProvider =
CLKSimpleTextProvider(text: stringa)
modularSmallTemplate.fillFraction = 0.95
modularSmallTemplate.ringStyle = CLKComplicationRingStyle.Closed
let template = CLKComplicationTimelineEntry(
date: NSDate(), complicationTemplate: modularSmallTemplate)
handler(template)
default:
handler(nil)
}
I have the switch IBAction in InterfaceController.swift.
I am encountering issues in using:
func updateComplication() {
let complicationServer = CLKComplicationServer.sharedInstance()
for complication in complicationServer.activeComplications {
complicationServer.reloadTimelineForComplication(complication)
}
}
Where do I have to write the above mentioned func, in order to be able to call it from inside the IBAction?
If I write it in ComplicationController.swift, by calling it from the IBAction in InterfaceController.swift as:
ComplicationController.updateComplication()
I get the error “Missing argument for parameter #1 in call”,
while if I write it in InterfaceController and call it in the IBAction, although the build is successful, when running the App and changing the value of the switch I get the following error: “fatal error: unexpectedly found nil while unwrapping an Optional value” on the line:
for complication in complicationServer.activeComplications
of func updateComplication.

Answer 1

It's not the placeholder text that you want to update. The placeholder template is a static template that's displayed in the selection screen for your complication while you are customizing your watch face. It's only called once to get the placeholder text, and doesn't get called when a timeline is reloaded.
The complication's current (actual, live) timeline entry is provided by getCurrentTimelineEntryForComplication. This function is where you should use your model's on state of the switch to create a CLKTextProvider containing a "N" or "Y" for the active complication family.
Finally, you should call updateComplication() from your switch IBAction to reload your complication timeline, which would update the current entry to show the new state of the switch on the watch face.
Since your complication is updated manually, you should return a nil updateDate in getNextRequestedUpdateDateWithHandler to avoid scheduling your complication for any regular updates.
Update for your edited question:
You should include the updateComplication function in your interface controller, as your complication controller isn't meant to be instantiated by you.
In regard to the "Unexpectedly found nil while unwrapping an Optional value" error, this is an issue that has been mentioned on the Apple Developer Forums.
If you are already running watchOS 2.1, you could try the latest watchOS beta to see if the issue has been fixed yet for 2.2. You should also file a bug report and dupe radar 22947535.