How to use the second parameter of callback of cordova plugin ble?

Question

I have an issue with sequence order when reading data from ble. This issue is referenced here

The version 1.2.4 of cordova-plugin-ble-central has a new parameter to get the sequence order and leave a chance to the client to reorder the packet. The PR is here. So the callback has a second parameter that is the sequence number:

ble.startNotification("device", "service", "characteristic", function (data, sequence) {
    /*
     * The sequence parameter will be undefined on iOS.  On Android it will be 
     * monotonically increasing, starting at 0 for the first call to this callback function
     * and then increasing by 1 for each callback in order.  There will be no gaps in
     * the sequence number so it is safe to wait forever for the next expected number.
     *
     * So, if you receive sequence 0 and then 2, it is guaranteed that 1 has already been 
     * processed by the plugin and dispatched into a queue for delivery so it will arrive
     * to your callback.
     */ 
}, function (err) {});

How can i use this sequence number in my ionic app? I receive an Observable and I don’t see how access this parameter:

this.ble.startNotification(device.handle,
BSC_SERVICE_UUID,
BSC_OUTPUT_CHARACTERISTIC_UUID).subscribe(y => {
         const x = new Uint8Array(y);
         ....
 });

Answer 1

The ionic wrapper emitted only the data array. I pushed a merged request to ionic-native repository here. Now the version 5.28.0 emit an array with at index 0 the data and at index 1 the sequence order