FRPTutorial snippets

frptutorial.swift

class ImageDownloader {
    func downloadImageFor(path:String) -> UIImage? {
        guard let url = NSURL(string: path) else { return nil }
        guard let data = NSData(contentsOfURL: url) else { return nil }
        return UIImage(data: data)
    }
}

class CMYKFilter : ImageFilter {
    
    // This is some unefficient and long time taking method
    func filterImage(image: UIImage) -> UIImage {
        // Extract Core Image
        guard let cgImage = image.CGImage else { return image }
        let coreImage = CIImage(CGImage: cgImage)
        
        // Filter
        let filter = CIFilter(name: "CICMYKHalftone")
        filter?.setValue(coreImage, forKey: kCIInputImageKey)
        
        // Handle output
        if let output = filter?.valueForKey(kCIOutputImageKey) as? CIImage {
            let context = CIContext(options: nil)
            let rect = output.extent
            let cgImage = context.createCGImage(output, fromRect:rect)
            let filteredImage = UIImage(CGImage: cgImage)
            return filteredImage
        } else {
            print("Filtering image failed")
            return image
        }
    }
    
}