iOS Tutorial Notifications with actions


It is possible to add a list of actions to the push notifications. The list becomes visible when the user 3d touches the notification or drags it with two fingers.
Note that it is an iOS 10+ feature.

Before you start make sure to first implement the standard push notifications and see that they work with the B4J code.

Steps to add actions:

1. Add this code at the end of the main module:
#AdditionalLib: UserNotifications.framework
#if OBJC
#import <UserNotifications/UserNotifications.h>
@interface b4i_main (notification) <UNUserNotificationCenterDelegate>
@implementation b4i_main (notification)
- (void)userNotificationCenter:(UNUserNotificationCenter *)center
didReceiveNotificationResponse:(UNNotificationResponse *)response
         withCompletionHandler:(void (^)(void))completionHandler {
       B4I* bi = [b4i_main new].bi;
[bi raiseEvent:nil event:@"usernotification_action:" params:@[response]];
#End If

Define the list of actions in SetCategories. Call SetCategories from ApplicationStart.

Sub SetCategories
   Dim category As NativeObject
   category = category.Initialize("UNNotificationCategory")
   'create a list with the action identifiers and titles: <--------------------------------------------
   Dim actions As List = Array(CreateAction("a1", "Action 1"), CreateAction("a2", "Action 2"))
   Dim intentIdentifiers As List = Array()
   category = category.RunMethod("categoryWithIdentifier:actions:intentIdentifiers:options:", _
       Array("category 1", actions, intentIdentifiers, 1))
   Dim NotificationCenter As NativeObject
   NotificationCenter = NotificationCenter.Initialize("UNUserNotificationCenter").RunMethod("currentNotificationCenter", Null)
   Dim set As NativeObject
   set = set.Initialize("NSSet").RunMethod("setWithObject:", Array(category))
   NotificationCenter.RunMethod("setNotificationCategories:", Array(set))
   NotificationCenter.SetField("delegate", Me)
End Sub

Sub CreateAction (Identifier As String, Title As String) As Object
   Dim acceptAction As NativeObject
   '5 = AuthenticationRequired + Foreground
   acceptAction = acceptAction.RunMethod("actionWithIdentifier:title:options:", Array(Identifier, Title, 5))
   Return acceptAction
End Sub

Private Sub UserNotification_Action (Response As Object)
   Dim n As NativeObject = Response
   Dim ActionIdentifier As String = n.GetField("actionIdentifier").AsString
   Msgbox($"User clicked on : ${ActionIdentifier}"$, "")
End Sub

Step 3: B4J code!
Set the category in the push notification json message:
Dim data As Map = CreateMap("title": Title, "body": Body)
   If Topic.StartsWith("ios_") Then
       Dim iosalert As Map =  CreateMap("title": Title, "body": Body, "sound": "default")
       iosalert.Put("click_action", "category 1") '<--------------------------------------
       m.Put("notification", iosalert)
   End If

UserNotification_Action event will be called when the user pressed on an action.


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Create a local notification with action items:
Sub Page1_Click
   CreateNotificationWithContent("This is the title", "Body", "identifer 2", "category 1", 5000)
End Sub

Sub CreateNotificationWithContent(Title As String, Body As String, Identifier As String, Category As String, MillisecondsFromNow As Long)
   Dim ln As NativeObject
   ln = ln.Initialize("UNMutableNotificationContent").RunMethod("new", Null)
   ln.SetField("title", Title)
   ln.SetField("body", Body)
   Dim n As NativeObject
   ln.SetField("sound", n.Initialize("UNNotificationSound").RunMethod("defaultSound", Null))
   If Category <> "" Then ln.SetField("categoryIdentifier", Category)
   Dim trigger As NativeObject
   trigger = trigger.Initialize("UNTimeIntervalNotificationTrigger").RunMethod("triggerWithTimeInterval:repeats:", Array(MillisecondsFromNow / 1000, False))
   Dim request As NativeObject
   request = request.Initialize("UNNotificationRequest").RunMethod("requestWithIdentifier:content:trigger:", _
       Array(Identifier, ln, trigger))
   Dim NotificationCenter As NativeObject
   NotificationCenter = NotificationCenter.Initialize("UNUserNotificationCenter").RunMethod("currentNotificationCenter", Null)
   NotificationCenter.RunMethod("addNotificationRequest:", Array(request))
End Sub