These two simple steps will allow you to configure versioned resource URLs in Spring MVC, allowing the browser to cache resources for an unlimited time and update version info on the URL when a resource is changed.
Here's a fun little experiment showing the power of Swift's Protocol Extensions to apply a CIGaussianBlur Core Image filter to any UIView with no developer overhead. The code could be extended to apply any Core Image filter such as a half tone screen or colour adjustment. Blurable is a simple protocol that borrows some of the methods and variables from a UIView: var layer: CALayer { get } var subviews: [UIView] { get } var frame: CGRect { get } func addSubview(view: UIView) func bringSubviewToFront(view: UIView) ...and adds a few of its own: Obviously, just being a protocol, it doesn't do much on its own. However, by adding an extension, I can introduce default functionality. Furthermore, by extending UIView to implement Blurable, every component from a segmented control to a horizontal slider can be blurred: extension UIView: Blurable { } The Mechanics of Blurable Getting a blurred representation of a UIView is pretty simple: I need to begin an image context, use the view's layer's renderInContext method to render into the context and then get a UIImage from the context: UIGraphicsBeginImageContextWithOptions(CGSize(width: frame.width, height: frame.height), false, 1) layer.renderInContext(UIGraphicsGetCurrentContext()!) let image = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext(); Once I have the image populated, it's a fairly standard workflow to apply a Gaussian blur to it: guard let blur = CIFilter(name: "CIGaussianBlur") else { return } blur.setValue(CIImage(image: image), forKey: kCIInputImageKey) blur.setValue(blurRadius, forKey: kCIInputRadiusKey) let ciContext = CIContext(options: nil) let result = blur.valueForKey(kCIOutputImageKey) as! CIImage! let boundingRect = CGRect(x: -blurRadius * 4, y: -blurRadius * 4, width: frame.width + (blurRadius * 8), height: frame.height + (blurRadius * 8)) let cgImage = ciContext.createCGImage(result, fromRect: boundingRect) let filteredImage = UIImage(CGImage: cgImage) A blurred image will be larger than its input image, so I need to be explicit about the size I require in createCGImage. The next step is to add a UIImageView to my view and hide all the other views. I've subclassed UIImageView to BlurOverlay so that when it comes to removing it, I can be sure I'm not removing an existing UIImageView: let blurOverlay = BlurOverlay() blurOverlay.frame = boundingRect blurOverlay.image = filteredImage subviews.forEach{ $0.hidden = true } addSubview(blurOverlay) When it comes to de-blurring, I want to ensure the last subview is one of my BlurOverlay remove it and unhide the existing views: func unBlur() { if let blurOverlay = subviews.last as? BlurOverlay { blurOverlay.removeFromSuperview() subviews.forEach{ $0.hidden = false } } } Finally, to see if a UIView is currently blurred, I just need to see if its last subview is a BlurOverlay: var isBlurred: Bool { return subviews.last is BlurOverlay } Blurring a UIView To blur and de-blur, just invoke blur() and unBlur() on an UIView: segmentedControl.unBlur() segmentedControl.blur(blurRadius: 2) Source Code As always, the source code for this project is available at my GitHub repository here. Enjoy!
I am going to explain how to use Spring Security in a Spring MVC Application to authenticate and authorize users against user details stored in a MySQL Database.
CORE
