Ask for Permission for Local Notifications in iOS 8, but still have the App Support iOS 7

Question

I have an app which uses local notifications. In iOS 7 everything works fine, but in iOS 8 the app needs to ask for user permission to display notifications. To ask for perm

Answer 1

In case you still want to compile against older SDKs or have a special reason to do so, you may try calling the whole stuff dynamically:

#ifdef __IPHONE_8_0
#define USING_IOS8_SDK
#else // iOS <8 SDK compatibility definitions
#define UIUserNotificationTypeNone    (0)
#define UIUserNotificationTypeBadge   (1 << 0)
#define UIUserNotificationTypeSound   (1 << 1)
#define UIUserNotificationTypeAlert   (1 << 2)
#endif


...

if ([_sharedApplication respondsToSelector:NSSelectorFromString(@"registerUserNotificationSettings:")])
{
    NSUInteger settingsParam = (UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound);
    id categoriesParam = nil;

#ifdef USING_IOS8_SDK

    // Perform direct call when using iOS 8 SDK
    [_sharedApplication registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:settingsParam categories:categoriesParam]];

#else
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"

    // Do the dynamic stuff

    // Get UIUserNotificationSettings class reference
    Class settings = NSClassFromString(@"UIUserNotificationSettings");
    if (settings) {

        // Prepare class selector
        SEL sel = NSSelectorFromString(@"settingsForTypes:categories:");

        // Obtain a method signature of selector on UIUserNotificationSettings class
        NSMethodSignature *signature = [settings methodSignatureForSelector:sel];

        // Create an invocation on a signature -- must be used because of primitive (enum) arguments on selector
        NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature];
        invocation.selector = sel;
        invocation.target = settings;

        // Set arguments
        [invocation setArgument:&settingsParam atIndex:2];
        [invocation setArgument:&categoriesParam atIndex:3];

        // Obtain an instance by firing an invocation
        NSObject *settingsInstance;
        [invocation invoke];
        [invocation getReturnValue:&settingsInstance];

        // Retain an instance so it can live after quitting method and prevent crash :-)
        CFRetain((__bridge CFTypeRef)(settingsInstance));

        // Finally call the desired method with proper settings
        if (settingsInstance)
            [_sharedApplication performSelector:NSSelectorFromString(@"registerUserNotificationSettings:") withObject:settingsInstance];
    }

#pragma clang diagnostic pop
#endif
}

This should perfectly compile on iOS 7 SDK and work (effectively) on iOS 8 devices, ignored on older ones.

Migrating your project to iOS 8 SDK is another solution, thought, but there are still options.