calling private iOS apis using nsinvocation

calling-private-ios-apis-using-nsinvocation.m

// https://www.swiftjectivec.com/calling-private-ios-apis-using-nsinvocation/

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];

    // Load in the private framework
    [[NSBundle bundleWithPath:@"/System/Library/PrivateFrameworks/TipKit.framework"] load];

    // Get our class type
    Class TPKContentView = NSClassFromString(@"TPKContentView");

    // Ignore undefined selector warnings below
    // Because clang can't tell me who I am

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundeclared-selector"
    // Create our two selectors to call
    SEL siriIconSel = @selector(SiriIconWithTraitCollection:);
    SEL tipsIconSel = @selector(TipsIconWithTraitCollection:);
#pragma clang diagnostic pop

    // These will be the result of the method invocations
    id returnValSiri;
    id returnValTips;

    // I know these methods take in a trait collection
    // From trial and error so I'll set it aside here
    // For readability
    UITraitCollection *traits = self.traitCollection;

    // Create the invocations. The first one, for Siri,
    // Is commented step by step...

    // Create an invocation using the type's method
    // Signature we want. So, the TPContentView we
    // Made earlier, and the selector we created above.
    NSInvocation *siriIconInvocation = [NSInvocation invocationWithMethodSignature:[TPKContentView methodSignatureForSelector:siriIconSel]];

    // Set that selector...
    [siriIconInvocation setSelector:siriIconSel];
    // And the target that'll attempt to respond to it...
    [siriIconInvocation setTarget:TPKContentView];

    // Pass the method the trait collection as
    // An argument, see why it's at index 2
    // After the code sample below.
    [siriIconInvocation setArgument:&traits atIndex:2];

    // Perform it, watch magic happen or
    // Your app explode...
    [siriIconInvocation invoke];

    // And assign the result to a variable.
    [siriIconInvocation getReturnValue:&returnValSiri];

    // And another for the tips
    NSInvocation *tipsIconInvocation = [NSInvocation invocationWithMethodSignature:[TPKContentView methodSignatureForSelector:tipsIconSel]];
    [tipsIconInvocation setSelector:tipsIconSel];
    [tipsIconInvocation setTarget:TPKContentView];
    [tipsIconInvocation setArgument:&traits atIndex:2];
    [tipsIconInvocation invoke];
    [tipsIconInvocation getReturnValue:&returnValTips];
}