gistfile1.m

int main(int argc, const char * argv[])
{
	@autoreleasepool {
		
		
		// Create a pretend Desktop and Documents folder
		NSString * desktopFolderPath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"Desktop"];
		NSString * documentsFolderPath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"Documents"];
		[[NSFileManager defaultManager] createDirectoryAtPath:desktopFolderPath withIntermediateDirectories:NO attributes:nil error:nil];
		[[NSFileManager defaultManager] createDirectoryAtPath:documentsFolderPath withIntermediateDirectories:NO attributes:nil error:nil];
		
		
		// URLs which we will reference
		NSURL * projectURLInDesktop = [NSURL fileURLWithPath:[desktopFolderPath stringByAppendingPathComponent:@"Project"]];
		NSURL * resourceURLInDesktop = [NSURL fileURLWithPath:[desktopFolderPath stringByAppendingPathComponent:@"Resource"]];
		NSURL * projectURLInDocuments = [NSURL fileURLWithPath:[documentsFolderPath stringByAppendingPathComponent:@"Project"]];
		NSURL * resourceURLInDocuments = [NSURL fileURLWithPath:[documentsFolderPath stringByAppendingPathComponent:@"Resource"]];
		
		
		
		
		// 1) User creates a file named Resource on the desktop
		[[NSData data] writeToURL:resourceURLInDesktop atomically:YES];
		
		// 2) User uses our application to create a project file named Project on the Desktop
		[[NSData data] writeToURL:projectURLInDesktop atomically:YES];
		
		
		
		// 3) User adds a reference to Resource into the project. Project will
		// contain an NSURL bookmark to Resource, and that bookmark will be
		// relative to the Project file's URL on the desktop.
		NSData * resourceBookmarkData = [resourceURLInDesktop bookmarkDataWithOptions:0 includingResourceValuesForKeys:nil
																		relativeToURL:projectURLInDesktop error:nil];
		
		
		// 4) Pretend that resourceBookmarkData is saved into the Project file
		// 5) Pretend that time has passed and our application has been quit.
		
		
		// 6) In Finder, let's say the user takes Project and Resource off of
		// the Desktop and moves them both into the Documents folder.
		[[NSFileManager defaultManager] moveItemAtURL:projectURLInDesktop toURL:projectURLInDocuments error:nil];
		[[NSFileManager defaultManager] moveItemAtURL:resourceURLInDesktop toURL:resourceURLInDocuments error:nil];
		
		
		// 7) Pretend that the user now creates a new file named Resource on
		// the Desktop. This file is entirely unrelated to Project.
		[[NSData data] writeToURL:resourceURLInDesktop atomically:YES];
		
		
		// 8) The user now opened our application again, and opens the Project.
		// When Project opens, it should resolve the bookmark data which
		// points to Resource. Since we saved the bookmark data as relative
		// to the Project file URL, when resolving the URL, it should be resolved
		// relative to the current Project file URL.
		NSURL * resolvedResourceURL = [NSURL URLByResolvingBookmarkData:resourceBookmarkData
																options:0
														  relativeToURL:projectURLInDocuments
													bookmarkDataIsStale:NULL
																  error:nil];
		
		// 9) At this point, we expect that the resolved URL should point to
		// the Resource file in the Documents folder, however it resolves
		// to the Resource file in the Desktop folder.
		
		// When the bookmark was created the relative path from Project to
		// Resource was simply "../Resource". When resolving the bookmark,
		// given that Project is in Documents, the resolved URL should
		// be "Documents/Project" + "../Resource" = "Documents/Resource".
		
		NSLog(@"Resolved URL file path should end in Documents/Resource.");
		NSLog(@"Resolved URL file path: %@", [resolvedResourceURL relativePath]);
		
		
		
		// --- Cleanup ---
		[[NSFileManager defaultManager] removeItemAtURL:resourceURLInDesktop error:nil];
		[[NSFileManager defaultManager] removeItemAtURL:projectURLInDocuments error:nil];
		[[NSFileManager defaultManager] removeItemAtURL:resourceURLInDocuments error:nil];
		[[NSFileManager defaultManager] removeItemAtPath:desktopFolderPath error:nil];
		[[NSFileManager defaultManager] removeItemAtPath:documentsFolderPath error:nil];
	}
	return 0;
}