./README.md in houston-2.2.4 vs ./README.md in houston-2.3.0

@@ -24,26 +24,27 @@
 require 'houston'
 
 # Environment variables are automatically read, or can be overridden by any specified options. You can also
 # conveniently use `Houston::Client.development` or `Houston::Client.production`.
 APN = Houston::Client.development
-APN.certificate = File.read("/path/to/apple_push_notification.pem")
+APN.certificate = File.read('/path/to/apple_push_notification.pem')
 
 # An example of the token sent back when a device registers for notifications
-token = "<ce8be627 2e43e855 16033e24 b4c28922 0eeda487 9c477160 b2545e95 b68b5969>"
+token = '<ce8be627 2e43e855 16033e24 b4c28922 0eeda487 9c477160 b2545e95 b68b5969>'
 
 # Create a notification that alerts a message to the user, plays a sound, and sets the badge on the app
 notification = Houston::Notification.new(device: token)
-notification.alert = "Hello, World!"
+notification.alert = 'Hello, World!'
 
 # Notifications can also change the badge count, have a custom sound, have a category identifier, indicate available Newsstand content, or pass along arbitrary data.
 notification.badge = 57
-notification.sound = "sosumi.aiff"
-notification.category = "INVITE_CATEGORY"
+notification.sound = 'sosumi.aiff'
+notification.category = 'INVITE_CATEGORY'
 notification.content_available = true
 notification.mutable_content = true
-notification.custom_data = { foo: "bar" }
+notification.custom_data = { foo: 'bar' }
+notification.url_args = %w[boarding A998]
 
 # And... sent! That's all it takes.
 APN.push(notification)
 ```
 
@@ -70,14 +71,14 @@
 puts "Error: #{notification.error}." if notification.error
 ```
 
 ### Silent Notifications
 
-To send a silent push notification, set `sound` to an empty string (`""`):
+To send a silent push notification, set `sound` to an empty string (`''`):
 
 ```ruby
-Houston::Notification.new(sound: "", content_available: true)
+Houston::Notification.new(sound: '', content_available: true)
 ```
 
 ### Mutable Notifications
 
 To send a mutable push notification (supported by iOS 10+), set `mutable_content` to `true`:
@@ -89,17 +90,17 @@
 ### Persistent Connections
 
 If you want to manage your own persistent connection to Apple push services, such as for background workers, here's how to do it:
 
 ```ruby
-certificate = File.read("/path/to/apple_push_notification.pem")
-passphrase = "..."
+certificate = File.read('/path/to/apple_push_notification.pem')
+passphrase = '...'
 connection = Houston::Connection.new(Houston::APPLE_DEVELOPMENT_GATEWAY_URI, certificate, passphrase)
 connection.open
 
 notification = Houston::Notification.new(device: token)
-notification.alert = "Hello, World!"
+notification.alert = 'Hello, World!'
 connection.write(notification.message)
 
 connection.close
 ```
 
@@ -116,13 +117,13 @@
 In `lib/tasks/notifications.rake`:
 
 ```ruby
 namespace :notifications do
   task device_token_feedback: [:environment] do
-    APN.devices.each do |device_hash|
+    APN.unregistered_devices.each do |device_hash|
       # Format: { token: token, timestamp: timestamp }
-      device = Device.find_by(token: device_hash['token'])
+      device = Device.find_by(token: device_hash[:token])
       next unless device.present?
       # Remove device token
       device.update_attribute(:device_token, nil)
     end
   end
@@ -139,13 +140,15 @@
 
     $ apn push "<token>" -c /path/to/apple_push_notification.pem -m "Hello from the command line! "
 
 ## Enabling Push Notifications on iOS
 
-### AppDelegate.m
+### Objective-C
 
 ```objective-c
+// AppDelegate.m
+
 - (void)applicationDidFinishLaunching:(UIApplication *)application {
   // ...
 
   [[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeAlert | UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeSound)];
 }
@@ -160,9 +163,27 @@
 
 - (void)application:(UIApplication *)application
 didFailToRegisterForRemoteNotificationsWithError:(NSError *)error
 {
     NSLog(@"Error: %@", error);
+}
+```
+
+### Swift 
+```swift
+// AppDelegate.swift
+
+func application(_ application: UIApplication, willFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
+    application.registerForRemoteNotifications()
+    return true
+}
+
+func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
+    // Register the device token with a webservice
+}
+
+func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
+    print("error \(error)")
 }
 ```
 
 ## Converting Your Certificate