Add support for handling window.prompt(..) etc in iOS mobile demo (PR #2121)

Merge from AnmAtAnm/ios-js-prompt

demos/mobile/ios/Blockly WebView.xcodeproj/xcuserdata/marshalla.xcuserdatad/xcschemes/xcschememanagement.plist

@@ -9,6 +9,11 @@
 			<key>orderHint</key>
 			<integer>0</integer>
 		</dict>
+		<key>Blockly WebView.xcscheme_^#shared#^_</key>
+		<dict>
+			<key>orderHint</key>
+			<integer>0</integer>
+		</dict>
 	</dict>
 </dict>
 </plist>

demos/mobile/ios/Blockly WebView/ViewController.swift

@@ -1,6 +1,5 @@
-//
 //  ViewController.swift
-//  Blockly WebView
+//  Blockly WebView UI controller.
 //
 //  Created by Andrew Marshall on 8/7/18.
 //  Copyright © 2018 Google. All rights reserved.
@@ -9,30 +8,104 @@
 import UIKit
 import WebKit
 
-class ViewController: UIViewController {
+
+/// A basic ViewController for a WebView.
+/// It handles the initial page load, and functions like window.prompt().
+class ViewController: UIViewController, WKUIDelegate {
     /// The name used to reference this iOS object when executing callbacks from the JS code.
     /// If this value is changed, it should also be changed in the `CODE_GENERATOR_BRIDGE_JS` file.
     fileprivate static let HOST_HTML = "Blockly/webview.html"
     
     @IBOutlet weak var webView: WKWebView!
-    
+ 
+    /// Additional setup after loading the UI NIB.
     override func viewDidLoad() {
         super.viewDidLoad()
+        webView.uiDelegate = self
         // Do any additional setup after loading the view, typically from a nib.
-        loadWebView()
+        loadWebContent()
     }
     
-    func loadWebView() {
-        if let htmlUrl = Bundle.main.url(forResource: "webview", withExtension: "html", subdirectory: "Blockly") {
+    /// Load the root HTML page into the webview.
+    func loadWebContent() {
+        if let htmlUrl = Bundle.main.url(forResource: "webview", withExtension: "html",
+                                         subdirectory: "Blockly") {
             webView.load(URLRequest.init(url: htmlUrl))
+        } else {
+            NSLog("Failed to load HTML. Could not find resource.")
         }
     }
 
-    override func didReceiveMemoryWarning() {
-        super.didReceiveMemoryWarning()
-        // Dispose of any resources that can be recreated.
+    /// Handle window.alert() with a native dialog.
+    func webView(_ webView: WKWebView,
+                 runJavaScriptAlertPanelWithMessage message: String,
+                 initiatedByFrame frame: WKFrameInfo,
+                 completionHandler: @escaping () -> Void) {
+        
+        let alert = UIAlertController(title: nil, message: message, preferredStyle: .alert)
+        let title = NSLocalizedString("OK", comment: "OK Button")
+        let ok = UIAlertAction(title: title, style: .default) { (action: UIAlertAction) -> Void in
+            alert.dismiss(animated: true, completion: nil)
+        }
+        alert.addAction(ok)
+        present(alert, animated: true)
+        completionHandler()
+    }
+    
+    /// Handle window.confirm() with a native dialog.
+    func webView(_ webView: WKWebView,
+                 runJavaScriptConfirmPanelWithMessage message: String,
+                 initiatedByFrame frame: WKFrameInfo,
+                 completionHandler: @escaping (Bool) -> Void) {
+        
+        let alert = UIAlertController(title: nil, message: message, preferredStyle: .alert)
+        let closeAndHandle = { (okayed: Bool) in
+            alert.dismiss(animated: true, completion: nil)
+            completionHandler(okayed)
+        }
+        
+        let okTitle = NSLocalizedString("OK", comment: "OK button title")
+        let ok = UIAlertAction(title: okTitle, style: .default) { (action: UIAlertAction) -> Void in
+            closeAndHandle(true)
+        }
+        alert.addAction(ok)
+        
+        let cancelTitle = NSLocalizedString("Cancel", comment: "Cancel button title")
+        let cancel = UIAlertAction(title: cancelTitle, style: .default) {
+            (action: UIAlertAction) -> Void in
+            closeAndHandle(false)
+        }
+        alert.addAction(cancel)
+        present(alert, animated: true)
+    }
+    
+    /// Handle window.prompt() with a native dialog.
+    func webView(_ webView: WKWebView,
+                 runJavaScriptTextInputPanelWithPrompt prompt: String,
+                 defaultText: String?,
+                 initiatedByFrame frame: WKFrameInfo,
+                 completionHandler: @escaping (String?) -> Void) {
+        
+        let alert = UIAlertController(title: prompt, message: nil, preferredStyle: .alert)
+        
+        alert.addTextField { (textField) in
+            textField.text = defaultText
+        }
+        
+        let okTitle = NSLocalizedString("OK", comment: "OK button title")
+        let okAction = UIAlertAction(title: okTitle, style: .default) { (_) in
+            let textInput = alert.textFields![0] as UITextField
+            completionHandler(textInput.text)
+        }
+        alert.addAction(okAction)
+        
+        let cancelTitle = NSLocalizedString("Cancel", comment: "Cancel button title")
+        let cancelAction = UIAlertAction(title: cancelTitle, style: .cancel) { (_) in
+            completionHandler(nil)
+        }
+        alert.addAction(cancelAction)
+        
+        present(alert, animated: true)
     }
-
-
 }