Improve UIAlertController APIs in the SwiftCatalog sample app (#92)

Samples/Catalog/Sources/AlertController.swift

@@ -19,12 +19,85 @@
 import Foundation
 import UIKit
 
+extension UIAlertAction {
+  /// Action types most commonly used
+  public enum ActionType {
+    ///Ok Option
+    case ok
+    /// Default Cancel Option
+    case cancel
+    /// Destructive action with custom title
+    case destructive(String)
+    /// Custom action with title and style
+    case custom(String, UIAlertActionStyle)
+
+    /**
+     Creates the action instance for UIAlertController
+     
+     - parameter handler: Call Back function
+     - returns UIAlertAction Instance
+     */
+    public func action(handler: ((String) -> Void)? = nil) -> UIAlertAction {
+      //Default value
+      var actionStyle = UIAlertActionStyle.default
+      var title = ""
+      // Action configuration based on the action type
+      switch self {
+
+      case .cancel:
+        actionStyle = .cancel
+        title = "Cancel"
+
+      case .destructive(let optionTitle):
+        title = optionTitle
+        actionStyle = .destructive
+
+      case .custom(let optionTitle, let style):
+        title = optionTitle
+        actionStyle = style
+
+      default:
+        title = "OK"
+      }
+      //Creating UIAlertAction instance
+      return UIAlertAction(title:title, style:actionStyle) { nativeAction in
+        if let handler = handler {
+          handler(title)
+        }
+      }
+
+    }
+  }
+}
+
 extension UIAlertController {
-  convenience init(title: String, message: String) {
-    self.init(title: title, message: message, preferredStyle: .alert)
-    let action = UIAlertAction(title: NSLocalizedString("OK", comment: "OK action"),
-                               style: .default,
-                               handler: nil)
-    addAction(action)
+  /**
+   Creates the alert view controller using the actions specified
+   
+   - parameter title:  Title of the alert.
+   - parameter message: Alert message body.
+   - parameter actions: Variable numbre of actions as an Array of actionType values.
+   - parameter style: UIAlertControllerStyle enum value
+   - parameter handler: Handler block/closure for the clicked option.
+   
+   */
+  convenience init(title: String,
+                   message: String,
+                   actions: UIAlertAction.ActionType?...,
+    style: UIAlertControllerStyle = .alert,
+    handler: ((String) -> Swift.Void)? = nil) {
+
+    //initialize the contoller (self) instance
+    self.init(title: title, message: message, preferredStyle: style)
+
+    if actions.isEmpty {
+      addAction(UIAlertAction.ActionType.ok.action(handler: handler))
+    } else {
+      //Fetching actions specidied by the user and adding actions accordingly
+      for actionType in actions {
+        addAction((actionType?.action(handler: handler))!)
+      }
+    }
+
   }
 }