CODEWITHSUNDEEP
objective-ccocoanotifications
TheSuper
TheSuper

Reputation: 645

NSUserNotificationCenter defaultNotificationcenter returns nil

I feel like I am going insane here.

I'm making a little command-line tool to let me know when a Twitch channel I like goes live. So far, everything works. There's only one, small issue: [NSUserNotificationCenter defaultUserNotificationCenter] is consistently returning nil, no matter where I call it in the program. This is a bit of a problem, since I need to be able to send notifications.

After a solid hour of googling, I can't figure out what's going on. Something like [[NSUserNotificationCenter defaultUserNotificationCenter] setDelegate:myDelegate] doesn't crash, but I'm pretty sure that's because you can send messages to nil in Obj-C. Similarly, I can do something like [[NSUserNotificationCenter defaultNotificationCenter] deliverNotification: mynote], but nothing is displayed onscreen (and this is with the delegate for [NSUserNotificationCenter defaultUserNotificationCenter] set to return YES for the userNotificationCenter:(NSUserNotificationCenter *)center shouldPresentNotification:(NSUserNotification *)method.)

Additionally, all notifications presented via deliverNotification do not have their delivered property set to YES.

The only thing I can think of is that the usage of NSUserNotificationCenter only works if you're running an NSApplication, but I cannot find that documented anywhere. I'm running a simple command-line tool, which is pretty much a main function, an @autoreleasepool, and some method calls.

Is there anything obvious that can cause [NSUserNotificationCenter defaultUserNotificationCenter] to return nil?

Upvotes: 4

Views: 437

Answers (1)

sergio
sergio

Reputation: 69027

The only thing I can think of is that the usage of NSUserNotificationCenter only works if you're running an NSApplication, but I cannot find that documented anywhere.

I don't think it would be easy to find it explicitly documented somewhere, but if your app is a simple command line tool, i.e., it is not using a NSRunLoop, I doubt that features like notifications can work at all. They intrinsically require your program to have a run loop that sits there waiting for events (e.g., a notification coming in, a click, a touch) and dispatching them to whomever should handle them.

You might try starting and NSRunLoop from you main function, but it would cease to be a simple command-line tool, I guess.

Upvotes: 2

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