iOS Question Firebase-push doesn't work for more than three tokens

[schimanski]

I use a server to send push-messages to different devices. For iOS-devices, I use the firebase-push-service. Every IOS-device will use the push-token to register to fcm with:

fm.SubscribeToTopic(File.ReadString(File.DirLibrary, "token.dat"))

In the following subs, I collect the ios-tokens to send the message to this. Now, after many units changed from android to ios, we mentioned, that it is not possible with this code to send a push to more than 3 devices. Up to 3, the messages are send without problems. More than 3, I get an 'Bad Request' in the Job_done-event. Is it not possible to send a push to multiple devices? For my way, it is better to collect different device-tokens instead of using main-topics...

   Case ID.StartsWith("ios:")
   ID=ID.Replace("ios:", "")
   iosTokens.Add(ID)
   If iosTokens.Size > 900 Then CallSubDelayed3(iOSPushFirebase, "SendMessageTo", iosTokens, msg)

Public Sub SendMessageTo(Devices As List, msg As Map)
   Try
     'Sammeln der tokens, an die die Nachrichte gesendet werden soll:
     Dim sb As StringBuilder
     sb.Initialize
     For Each t As String In Devices
      sb.Append($"'${t}' in topics ||"$)
     Next
     sb.Remove(sb.Length-3, sb.Length) 'will fail if topics is empty
     Dim m As Map = CreateMap("condition": sb.ToString)
     
     Dim Job As HttpJob
     Job.Initialize("fcm", Me)
     
     m.Put("data", msg)
     
     If msg.get("steuerbefehl")<>"" Then
       m.Put("priority", 10)
       m.Put("content_available", False)
     Else
       
       Dim notifytitle As String
       notifytitle=msg.Get("absender")
       
       'Für Nichtsteuerbefehle und Schlagzeilen wird eine RemoteNotication vom Server ohne Ton gesendet.
       Dim iosalert As Map =  CreateMap("title": notifytitle, "body": "neue Informationen")
       m.Put("notification", iosalert)
       m.Put("priority", 10)
       m.Put("content_available", True)
      
     End If
     
     Dim jg As JSONGenerator
     jg.Initialize(m)
     Job.PostString("https://fcm.googleapis.com/fcm/send", jg.ToString)
     Job.GetRequest.SetContentType("application/json;charset=UTF-8")
     Job.GetRequest.SetHeader("Authorization", "key=" & Main.FirebasePushApiKey)
   Catch
     Main.Logger.logsFATAL(LastException.Message)
   End Try
End Sub

Sub JobDone(job As HttpJob)
   If job.Success=False Then
     Main.Logger.logsInfo("iOS-Geraet(e) konnten nicht gepusht werden! " & job.ErrorMessage)   
     End If
     job.Release
End Sub

 

[Erel]

Is the topic unique to each device? It will be easier to use the device native token instead.

 

[schimanski]

Yes, the token is unique. It is the token, which the device gets in the Application_PushToken after registration and I use this token as topic. I think, that's not a good idea

 

[Erel]

The message format is documented here: https://firebase.google.com/docs/cloud-messaging/http-server-ref#downstream

It says: "Maximum two operators per topic message supported."
I guess that it means that you are limited to two operators.

You should registration_ids instead. It supports up to 1000 ids or topics.

 

[schimanski]

I have read the documentation, but for me, it is not clear, if the device-registration-token is the same as the registration_id.
I tried

Dim t as string = ios_token
Dim m As Map = CreateMap("registration_ids": t)

I don't understand, how to implement it...

 

[Erel]

It expects an array:

Dim m As Map = CreateMap("registration_ids": Array(id1, id2, id3))

 

[schimanski]

I have tried it over your SendingTool with the token which I get from the the

Private Sub Application_PushToken(Success as Boolean, Token() as Byte)
    If Success then
        Dim bc as ByteConverter
        dim ID as string = bc.HexFromBytes(Token)       '=48CE7F765C608CA8C391E1275756C7DC2C6784D65240B1D220XXXXXXXX"
        ...

and then

  Dim m As Map = CreateMap("registration_ids": Array("48CE7F765C608CA8C391E1275756C7DC2C6784D65240B1D220XXXXXXXX"))
  ...

instead of the topic-code.

I get this failure:

{"multicast_id":5488704055604325806,"success":0,"failure":1,"canonical_ids":0,"results":[{"error":"InvalidRegistration"}]}

I tried it with different devices and I registered them all new in fcm..
In the client-code, I deleted the line

fm.SubscribeToTopc(...

 

[schimanski]

Sorry, I found it:

FirebaseNotifications / Push Messages (server not required)

It was the wrong token. Thanks you for your efforts.