NSDictionaryOfVariableBindings swift equivalent?

Question

The Apple documentation shows an unsettling blank space under the \'Creating a Dictionary\' section of the UIKit reference here.

Has anyone found a replacement for

Answer 1

ObjC runtime to the rescue!

i created an alternate solution, but it only works if each of the views are instance variables of the same object.

func DictionaryOfInstanceVariables(container:AnyObject, objects: String ...) -> [String:AnyObject] {
    var views = [String:AnyObject]()
    for objectName in objects {
        guard let object = object_getIvar(container, class_getInstanceVariable(container.dynamicType, objectName)) else {
            assertionFailure("\(objectName) is not an ivar of: \(container)");
            continue
        }
        views[objectName] = object
    }
    return views
}

can be used like this:

class ViewController: UIViewController {

    var childA: UIView = {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = UIColor.redColor()
        return view
    }()

    var childB: UIButton = {
        let view = UIButton()
        view.setTitle("asdf", forState: .Normal)
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = UIColor.blueColor()
        return view
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.addSubview(childA)
        self.view.addSubview(childB)

        let views = DictionaryOfInstanceVariables(self, objects: "childA", "childB")
        self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[childA]|", options: [], metrics: nil, views: views))
        self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[childB]|", options: [], metrics: nil, views: views))
        self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[childA][childB(==childA)]|", options: [], metrics: nil, views: views))

    }

}

unfortunately you still have to type the variable name in as a string, but it will at least assert if there is a typo. this definitely won't work in all situations, but helpful nonetheless