Added VoIP Notifications support for iOS (#2194)

* Ios VoIP Push feature

* VoIP feature bugs fixed

* VoIP JS connector

* VoIPPush feature included in the main PushPlugin class

* VoIP feature: Removed sources from config.xml

* VoIP feature: PushKit framework fixed in plugin.xml

* Update API.md

* Update PAYLOAD.md

* API.md suggestions modified

* PushPlugin.m pull request requested changes

* push.js reverted to previous commit

* PushPlugin.m removed unused code

docs/API.md

@@ -66,6 +66,7 @@ All iOS boolean options can also be specified as `string`
 
 Attribute | Type | Default | Description
 --------- | ---- | ------- | -----------
+`ios.voip` | `boolean` | `false` | Optional. If `true` the device will be set up to receive VoIP Push notifications and the other options will be ignored since VoIP notifications are silent notifications that should be handled in the "notification" event.
 `ios.alert` | `boolean` | `false` | Optional. If `true` the device shows an alert on receipt of notification. **Note:** the value you set this option to the first time you call the init method will be how the application always acts. Once this is set programmatically in the init method it can only be changed manually by the user in Settings>Notifications>`App Name`. This is normal iOS behaviour.
 `ios.badge` | `boolean` | `false` | Optional. If `true` the device sets the badge number on receipt of notification. **Note:** the value you set this option to the first time you call the init method will be how the application always acts. Once this is set programmatically in the init method it can only be changed manually by the user in Settings>Notifications>`App Name`. This is normal iOS behaviour.
 `ios.sound` | `boolean` | `false` | Optional. If `true` the device plays a sound on receipt of notification. **Note:** the value you set this option to the first time you call the init method will be how the application always acts. Once this is set programmatically in the init method it can only be changed manually by the user in Settings>Notifications>`App Name`. This is normal iOS behaviour.
@@ -99,6 +100,28 @@ Make sure that the certificate you build with matches your `fcmSandbox` value.
 
 > Note: The integration between GCM and APNS is a bit finicky. Personally, I feel it is much better to send pushes to Android using GCM and pushes to iOS using APNS which this plugin does support.
 
+#### iOS VoIP Notifications
+
+It is possible to receive VoIP Notifications in iOS that can execute the "notification" event also when the application is in background or closed.
+
+This type of notifications consist only of payload data, so the developer is the responsible of handling the event and do whatever the aplication should do when receiving one of them. The cordova-plugin-local-notifications is a good complement for the VoIP feature.
+
+In order to use the VoIP Notifications, you have to create a VoIP Services Certificate. There are a lot of tutorials on the web to achieve this. Once created, you must use this certificate in order to communicate with the APN Service.
+
+To set up the VoIP Notification in ios do:
+```javascript
+const push = PushNotification.init({
+  ios: {
+		voip: true
+	}
+});
+```
+Once set up the voip parameter to true, the rest of the options will be ignored.
+
+The "hasPermission" success callback will return data.isEnabled to false since there is no need to approve to use this type of notifications.
+
+The "finish" method has not use too when the VoIP notifications are enabled.
+
 ### Example
 
 ```javascript

docs/PAYLOAD.md

@@ -30,6 +30,7 @@
 - [iOS Behaviour](#ios-behaviour)
   - [Sound](#sound-1)
   - [Background Notifications](#background-notifications-1)
+  - [VoIP Notifications](#voip-notifications)
   - [Action Buttons](#action-buttons-1)
     - [Action Buttons using GCM on iOS](#action-buttons-using-gcm-on-ios)
   - [GCM and Additional Data](#gcm-and-additional-data)
@@ -1654,6 +1655,16 @@ push.on('notification', (data) => {
 
 It is absolutely critical that you call `push.finish()` when you have successfully processed your background push data.
 
+## VoIP Notifications
+
+VoIP Notifications are a type of iOS notifications that are always received and handled also when the app is closed or in background and consist only of payload data, so the developer is the responsible of handling the event and do whatever the aplication should do when receiving one of them. The cordova-plugin-local-notifications is a good complement for the VoIP feature.
+
+In order to maintain the plugin data transfer standard, the payload sent to aps maintains the same structure as the one of common notifications with the consideration that the notification will be always be silent independently of the params that you pass to it.
+
+The `on('notification')` event handler will always be called excepting if Background App Refresh is disabled on the user's iOS device. (Settings > General > Background App Refresh).
+
+In order to set up your application with this type of notifications, refer to the [API guide](API.md#ios-voip-notifications).
+
 ## Action Buttons
 
 Your notification can include action buttons. For iOS 8+ you must setup the possible actions when you initialize the plugin:

plugin.xml

@@ -68,6 +68,7 @@
     <config-file target="*-Info.plist" parent="UIBackgroundModes">
       <array>
         <string>remote-notification</string>
+        <string>voip</string>
       </array>
     </config-file>
     <config-file target="*-Debug.plist" parent="aps-environment">
@@ -81,6 +82,7 @@
     <header-file src="src/ios/AppDelegate+notification.h"/>
     <header-file src="src/ios/PushPlugin.h"/>
     <framework src="FirebaseMessaging" type="podspec" spec="~> 2.0.0"/>
+    <framework src="PushKit.framework" />
   </platform>
   <platform name="windows">
     <hook type="after_plugin_install" src="hooks/windows/setToastCapable.js"/>
@@ -91,4 +93,4 @@
       <preference name="WindowsToastCapable" value="true"/>
     </config-file>
   </platform>
-</plugin>
+</plugin>

src/ios/PushPlugin.h

@@ -26,6 +26,7 @@
 #import <Foundation/Foundation.h>
 #import <Cordova/CDV.h>
 #import <Cordova/CDVPlugin.h>
+#import <PushKit/PushKit.h>
 
 @protocol GGLInstanceIDDelegate;
 @protocol GCMReceiverDelegate;
@@ -68,6 +69,10 @@
 - (void)didSendDataMessageWithID:(NSString *)messageID;
 - (void)didDeleteMessagesOnServer;
 
+// VoIP Features
+- (void)pushRegistry:(PKPushRegistry *)registry didUpdatePushCredentials:(PKPushCredentials *)credentials forType:(NSString *)type;
+- (void)pushRegistry:(PKPushRegistry *)registry didReceiveIncomingPushWithPayload:(PKPushPayload *)payload forType:(NSString *)type;
+
 // FCM Features
 @property(nonatomic, assign) BOOL usesFCM;
 @property(nonatomic, strong) NSNumber *fcmSandbox;