Symbol not found: kUTTypeImage

I copied some bits of code from apple's documentation- and I got these 2 errors:

Undefined symbols for architecture i386:
  "_kUTTypeImage", referenced from:
      -[ImagePicker imagePickerController:didFinishPickingMediaWithInfo:] in ImagePicker.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

What am I doing wrong?

EDIT: The code:

- (IBAction) showSavedMediaBrowser {
    [self startMediaBrowserFromViewController: self
                                usingDelegate: (id)self];
}

- (BOOL) startMediaBrowserFromViewController: (UIViewController*) controller
                               usingDelegate: (id <UIImagePickerControllerDelegate,
                                               UINavigationControllerDelegate>) delegate {
    
    if (([UIImagePickerController isSourceTypeAvailable:
          UIImagePickerControllerSourceTypeSavedPhotosAlbum] == NO)
        || (delegate == nil)
        || (controller == nil))
        return NO;
    
    UIImagePickerController *mediaUI = [[UIImagePickerController alloc] init];
    mediaUI.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
    
    // Displays saved pictures and movies, if both are available, from the
    // Camera Roll album.
    mediaUI.mediaTypes =
    [UIImagePickerController availableMediaTypesForSourceType:
     UIImagePickerControllerSourceTypeSavedPhotosAlbum];
    
    // Hides the controls for moving & scaling pictures, or for
    // trimming movies. To instead show the controls, use YES.
    mediaUI.allowsEditing = YES;
    
    mediaUI.delegate = delegate;
    
    [controller presentViewController:mediaUI animated:YES completion:nil];
    return YES;
}

- (void) imagePickerController: (UIImagePickerController *) picker
 didFinishPickingMediaWithInfo: (NSDictionary *) info {
    
    NSString *mediaType = [info objectForKey: UIImagePickerControllerMediaType];
    UIImage *originalImage, *editedImage, *imageToUse;
    
    // Handle a still image picked from a photo album
    if (CFStringCompare ((__bridge_retained CFStringRef) mediaType, kUTTypeImage, 0)
        == kCFCompareEqualTo) {
        
        editedImage = (UIImage *) [info objectForKey:
                                   UIImagePickerControllerEditedImage];
        originalImage = (UIImage *) [info objectForKey:
                                     UIImagePickerControllerOriginalImage];
        
        if (editedImage) {
            imageToUse = editedImage;
        } else {
            imageToUse = originalImage;
        }
        // Do something with imageToUse
    }
    
    [[picker parentViewController] dismissModalViewControllerAnimated: YES];
}

    

I think the error is where the last method starts, but I'm not sure.

Your post does not have much context to explain the code sections; please explain your scenario more clearly.

Look up the symbol (kUTTypeImage) and locate the image/library it should exist in (MobileCoreServices.framework in this case). Then link your binary with that framework.

Obligatory Swift answer:

import MobileCoreServices

When use with UIDocumentPickerViewController do:

import MobileCoreServices

let type = String(kUTTypeImage)
let documentPickerViewController = UIDocumentPickerViewController(documentTypes: [type], in: .import)

For Swift it appears to be in

import UniformTypeIdentifiers

let type = String(describing: UTType.image)