PubNub Chat

Deleting Messages

Since PubNub stores all messages in a time-series database, it doesn’t expose an API to directly update a message. However, clients can update messages (or soft delete them) by passing another version of the message using the Message Actions feature.

Soft delete a message

Use the addMessageAction method to soft delete a message after it has been published by adding an action to it.

Soft deleting a message just attaches a delete flag to the message. Refer to hard delete if you want to permanently delete the message from storage for compliance reasons.

Go to SDK

pubnub.addMessageAction(
  {
    channel: 'ch-1'
    messageTimetoken: '15610547826970040',
    action: {
      type: 'deleted',
      value: '.',
    },
  },
  function(status, response) {
  }
);

Go to SDK

extension MyAppMessageAction: MessageAction {}

let action = MyAppMessageAction(type: "deleted", value: ".")

pubnub.addMessageAction(
  channel: "ch-1",
  message: action,
  messageTimetoken: 15610547826969050
) { result in
  switch result {
  case let .success(response):
    print("Successfully Message Action Add Response: \(response)")
  case let .failure(error):
    print("Error from failed response: \(error.localizedDescription)")
  }
})

Go to SDK

pubnub.addMessageAction()
    .channel("ch-1")
    .messageAction(new PNMessageAction()
            .setType("deleted")
            .setValue(".")
            .setMessageTimetoken(15701761818730000L)
    )
    .async(new PNCallback<PNAddMessageActionResult>() {
        @Override
        public void onResponse(PNAddMessageActionResult result, PNStatus status) {
            if (!status.isError()) {
                System.out.println(result.getType());
                System.out.println(result.getValue());
                System.out.println(result.getUuid());
                System.out.println(result.getActionTimetoken());
                System.out.println(result.getMessageTimetoken());
            } else {
                status.getErrorData().getThrowable().printStackTrace();
            }
        }
    })

Go to SDK

MessageActionAdd messageAct = new MessageActionAdd();
messageAct.ActionType = "deleted";
messageAct.ActionValue = ".";

pubnub.AddMessageActions().Channel("ch-1").MessageAction(messageAct).MessageTimetoken(15701761818730000).Async((result, status) => {
        if (!status.Error) {
            Debug.Log("result.ActionTimetoken: " + result.ActionTimetoken);
            Debug.Log("result.ActionType: " + result.ActionType);
            Debug.Log("result.ActionValue: " + result.ActionValue);
            Debug.Log("result.MessageTimetoken: " + result.MessageTimetoken);
            Debug.Log("result.UUID: " + result.UUID);
        } else {
            Debug.Log(status.Error);
            Debug.Log(status.ErrorData.Info);
        }
});

PubNub triggers events when messages are soft deleted using message actions. Users subscribed to the channel can receive these events and mark the message as deleted.

{
   "channel":"main",
   "subscription":null,
   "timetoken":"15871508399473609",
   "publisher":"user-1",
   "message":{
      "source":"actions",
      "version":"1.0",
      "action":"added",
      "data":{
         "type":"deleted",
         "value":".",
         "messageTimetoken":"15632184115444390",
         "actionTimetoken":"15632184115444394"
      }
   }
}

Hard delete a message

The deleteMessages method permanently deletes messages from storage in a given channel. You can delete a single message, or a range of messages.

In the above below, the start and end timetoken parameter values are 1/10 nanosecond (last digit of timetoken) apart to delete the message stored at the end parameter's timetoken value.

Performance

You need to turn on the Enable Delete-From-History setting from your PubNub Dashboard in order to hard delete messages. We do not recommend heavy use of this API for performance reasons. Messages should be soft deleted when possible.

pubnub.deleteMessages(
  {
    channels: 'chats.room1',
    start: "15526611838554309",
    end: "15526611838554310",
  },
  function (status, response) {
    console.log(status, response);
  }
);
pubnub.deleteMessageHistory(
  from: "chats.room1",
  start: 15526611838554309,
  end: 15526611838554310
) { result in
  switch result {
    case let .success(response):
      print("Successful Message Deletion Response: \(response)")

    case let .failure(error):
      print("Failed Message Deletion Response: \(error.localizedDescription)")
  }
}
[self.client deleteMessagesFromChannel:@"chats.room1"
    start:@15526611838554309 end:@15526611838554310
    withCompletion:^(PNAcknowledgmentStatus *status) {

  if (status.isError) {
    // handle error condtion
  }
  else {
    // confirm delete success
  }
}];
pubnub.deleteMessages()
  .channels(Arrays.asList("chats.room1"))
  .start(15526611838554309L)
  .end(15526611838554310L)
  .async(new PNCallback<PNDeleteMessagesResult>() {
    @Override
    public void onResponse(PNDeleteMessagesResult result, PNStatus status) {
      // handle success or failure of the delete
    }
  });
pubnub.DeleteMessages().Channel("chats.room1")
  .Start(15526611838554309)
  .End(15526611838554310)
  .Execute(new PNDeleteMessageResultExt((result, status) => {
      if (status != null && status.Error) {
        Console.WriteLine(status.ErrorData.Information);
      }
      else if (result != null) {
        Console.WriteLine(pubnub.JsonPluggableLibrary.SerializeToJsonString(result));
      }
    }
  ));
envelope = PubNub(pnconf).delete_messages().channel('chats.room1') \
  .start(15526611838554309) \
  .end(15526611838554310) \
  .sync()
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