DictionaryOfInstanceVariables - Swift version of NSDictionaryOfVariableBindings

DictionaryOfInstanceVariables.swift

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
}

// Example Usage

import UIKit

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: "childC", "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))
        
    }
}

small note for swift 3.1

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

AnyObject --> Any
container.dynamicType --> type(of: container)

Regards,

Sergey