ccabanero · January 10, 2017 23:49 · Jan 10, 2017
diff --git a/Swift 3 Protocol Pattern Snippet b/Swift 3 Protocol Pattern Snippet
@@ -0,0 +1,53 @@
+
+// set up - MapViewController is the parent.  A ContainerView is used to place the UI for directions - part of the DirectionsViewController.
+// The DirectionsViewController has a protocol method for letting the delegate know when a user has tapped the 'get directions' button and passes the to and from data
+
+// this ViewController is the delegate for the DirectionsViewController
+Class MapViewController: UIViewController, DirectionsViewControllerDelegate {
+
+    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
+
+        // for getting access to the DirectionsViewController and settings its delegate as THIS controller
+        if segue.identifier == segueIdToDirectionsVC {
+
+            if let destinationVC = segue.destination as? DirectionsViewController {
+
+                destinationVC.delegate = self
+            }
+        }
+    }  
+
+    func didRequestDirections(locations: (from: String, to: String)) {
+
+        print("user tapped - get directions | to: \(locations.from) and from: \(locations.to)")
+
+    }
+}
+
+....
+
+protocol DirectionsViewControllerDelegate: class {
+
+    func didRequestDirections(locations: (from: String, to: String))
+}
+
+class DirectionsViewController: UIViewController {
+
+    weak var delegate: DirectionsViewControllerDelegate?
+
+    @IBOutlet weak var fromTextField: UITextField!
+    @IBOutlet weak var toTextField: UITextField!
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+    }
+
+    // MARK: - Directions    
+    @IBAction func handleDirectionsButtonTap(_ sender: Any) {
+
+        if let fromText = fromTextField.text, let toText = toTextField.text {
+
+            delegate?.didRequestDirections(locations: (from: fromText, to: toText))
+        }
+    }
+}
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