I'm trying to subscribe to notification changes from a BLE device that I built, and print the value of the notification. I know the characteristic UUID that I want to read the notifications from:
scanSubscription = rxBleClient.scanBleDevices(
ScanSettings.Builder().build(),
ScanFilter.Builder().setDeviceName("MyDevice").build() // Filter for devices named MyDevice
)
.take(1) // stop the scan when a matching device will be scanned for the first time
.flatMap {
val device = it.bleDevice
device.establishConnection(false)
.flatMap < Any > {
rxBleConnection: RxBleConnection - > rxBleConnection.setupNotification(charUUID)
}
.doOnNext {
notificationObservable: Any ? - >
}
.flatMap < Any > {
notificationObservable: Any ? - > notificationObservable
} // <-- Notification has been set up, now observe value changes.
}
.subscribe({ /* written */ }, {
throwable - >
// Handle an error here.
// println("Scan Error: $throwable")
})
To prove that the device is working as intended, I observe the notification changes using the BLE Scanner app for Android.
When I wave my hand over the sensor, the value changes. In my case, it increments.
My question is how can I print that value when the notification value changes? When debugging, I can't get the Count to print. It doesn't even appear in my console.
Usually on Android one uses Log class to log data to logcat. You could use it like this:
scanSubscription = rxBleClient.scanBleDevices(
ScanSettings.Builder().build(),
ScanFilter.Builder().setDeviceName("MyDevice").build() // Filter for devices named MyDevice
)
.take(1) // stop the scan when a matching device will be scanned for the first time
.flatMap {
val device = it.bleDevice
device.establishConnection(false)
.flatMap < Any > {
rxBleConnection: RxBleConnection - > rxBleConnection.setupNotification(charUUID)
}
.doOnNext {
notificationObservable: Any ? - >
}
.flatMap < Any > {
notificationObservable: Any ? - > notificationObservable
} // <-- Notification has been set up, now observe value changes.
}
.subscribe(
{ notification -> Log.i("Notification!", notification.contentToString()) },
{ throwable -> Log.e("Whoops!", "Scan Error", throwable) }
)
Related
I am trying to send the 128 bytes of the block to BLE Controller using the RxAndroidBle library. the flow to send data from mobile to BLE controller is as follows
Connect with BLE Controller
Start OTA (sending 1)
Send CRC (of the data block)
Send data block
wait for 2 seconds
repeat step 3
END OTA (sending 2)
Here is snapshot of a code
.flatMap(rxBleConnection -> prepareWriting())
.flatMapIterable(otaMetaData -> otaMetaData)
.zipWith(Observable.interval(2, TimeUnit.SECONDS), (item, interval) -> item)
.doOnNext(metaData -> {
otaMetaData = metaData;
})
.map(otaMetaData -> {
return mRxBleConnection.writeCharacteristic(OTA_CHECKSUM, otaMetaData.getCrcBlock()).toObservable();
})
.doOnNext(otaMetaData -> {
Log.e(TAG, "Writing CRC " + Arrays.toString(BLEUtils.toHex(otaMetaData.getCrcBlock())));
})
.map(bytes -> {
return mRxBleConnection.writeCharacteristic(OTA_DATA, otaMetaData.getDataBlock()).toObservable();
})
.doOnNext(otaMetaData -> {
Log.e(TAG, "Writing Data " + Arrays.toString(BLEUtils.toHex(otaMetaData.getDataBlock())));
})
.flatMap(bytes -> mRxBleConnection.writeCharacteristic(OTA_CONTROL,OTA_DATA_END).toObservable())
The problem is while sending the END OTA because as the flatMapIterable returns 20 items, .flatMap(bytes -> mRxBleConnection.writeCharacteristic(OTA_CONTROL,OTA_DATA_END) is getting called 20 times.
So, I am not sure how I can send the OTA_DATA_END command when all the 20 items get processed. Moreover, any suggestion to improve the existing code is welcome.
You can use flatMapIterable() with toList(). Try to add toList() operator before OTA_DATA_END command like:
.toList() // wait for all commands to complete
.flatMap(bytes -> mRxBleConnection.writeCharacteristic(OTA_CONTROL,OTA_DATA_END).toObservable())
EDIT
Better to separate steps like
.flatMap(rxBleConnection -> prepareWriting())
.flatMap(otaMetaData -> Observable.fromIterable(otaMetaData)
.zipWith(Observable.interval(2, TimeUnit.SECONDS), (metaData, interval) -> metaData)
.flatMap(metaData -> {
return mRxBleConnection.writeCharacteristic(OTA_CHECKSUM, metaData.getCrcBlock())
.toObservable();
}, (metaData, bytes) -> metaData) /* result selector */
.flatMap(metaData -> {
return mRxBleConnection.writeCharacteristic(OTA_DATA, metaData.getDataBlock())
.toObservable();
}, (metaData, bytes) -> metaData)
.toList()
.toObservable()
)
.flatMap(otaMetaData -> {
return mRxBleConnection.writeCharacteristic(OTA_CONTROL, OTA_DATA_END)
.toObservable();
})
I'm trying to read an unsolicited data stream from my Bluetooth device. The data should appear as a byte array. Unfortunately, the UUID I'm supplying doesn't seem to be the correct one. What could be going wrong?
val stringDeviceUUID = rxBleDevice.bluetoothDevice.uuids[0].toString()
val charUUID = UUID.fromString(stringDeviceUUID)
println("$stringDeviceUUID = $charUUID?")
/* If device if it is not already connected... */
if (rxBleDevice.connectionState != RxBleConnection.RxBleConnectionState.CONNECTED) {
/* Establish connection to device */
device !!.establishConnection(false) ?
.doOnNext {
_ -> Log.d("Device: ", "Connection Established")
} ?
.flatMapSingle {
rxBleConnection -> rxBleConnection.readCharacteristic(charUUID)
} ? .subscribe({
count ->
// count should be in bytes
println("OUTPUT: $count")
}, {
throwable ->
Log.d("Device: ", "$throwable")
})
}
I get the following error:
D/Device:: com.polidea.rxandroidble2.exceptions.BleCharacteristicNotFoundException: Characteristic not found with UUID 00001101-0000-1000-8000-00805f9b34fb
What is wrong with this UUID? This is precisely the UUID I retrieve from the device so why won't it let me communicate?
It can't be seen from your code snippet, but are rxBleDevice and device the same RxAndroidBle instance? If not, perhaps replace device !!.establishConnection(false) with rxBleDevice.establishConnection(false)
I'm trying to listen to whether my app is connected to a bluetooth device. I'm trying to print the connectionState result but the application is not even reaching the first println so I can't check what they may be. I want to enumerate the possible connection states, and then to adjust the UI in response. How can I do this?
val rxBleClient = RxBleClient.create(this.context!!)
val bleDevice = rxBleClient.getBleDevice("34:81:F4:3C:2D:7B")
val disposable = bleDevice.establishConnection(true) // <-- autoConnect flag
.subscribe({
rxBleConnection ->
// All GATT operations are done through the rxBleConnection.
bleDevice.observeConnectionStateChanges()
.subscribe({
connectionState ->
println("Connection State: $connectionState")
if (connectionState != null) {
enableBluetooth.setBackgroundResource(R.drawable.bluetooth_on) // Change image
deviceConnected.setText(R.string.connected_to_hooplight) // Changed text
} else {
enableBluetooth.setBackgroundResource(R.drawable.bluetooth_off) // Change image
deviceConnected.setText(R.string.connect_to_hooplight) // Changed text
}
}, {
throwable ->
Log.d("Error: ", throwable.toString())
})
}, {
throwable ->
// Handle an error here.
Log.d("Error: ", throwable.toString())
})
// When done... dispose and forget about connection teardown :)
disposable.dispose()
There are two things to the above code:
disposable.dispose() should be called when the flow that was subscribed is no longer needed. If the dispose method is called right after subscription nothing will actually happen. That is why even the first println does not show up.
The bleDevice.establishConnection() and bleDevice.observeConnectionStateChanges() are not dependent on each other functionally. Connection does not have to be established to observe changes. Even if one would start observing the changes after the connection is on it will only get info when the connection is closed (because it is the first change since then)
A better way would be to decouple the observing connection changes flow and the actual connection. An example code:
val observingConnectionStateDisposable = bleDevice.observeConnectionStateChanges()
.subscribe(
{ connectionState ->
Log.d("Connection State: $connectionState")
if (connectionState == RxBleConnectionState.CONNECTED) { // fixed the check
enableBluetooth.setBackgroundResource(R.drawable.bluetooth_on) // Change image
deviceConnected.setText(R.string.connected_to_hooplight) // Changed text
} else {
enableBluetooth.setBackgroundResource(R.drawable.bluetooth_off) // Change image
deviceConnected.setText(R.string.connect_to_hooplight) // Changed text
}
},
{ throwable -> Log.d("Error: ", throwable.toString()) }
)
val connectionDisposable = bleDevice.establishConnection(false)
.subscribe(
{ Log.d("connection established") }, // do your thing with the connection
{ throwable -> Log.d("Error on connection: ${throwable}") }
)
I'm updating an app to use RxAndroidBLE, and struggling with how to translate my existing callback pattern into an Rx pattern. In particular, I need to respond to characteristic notifications in different ways depending on the received data, and send a specific write command back to the device (which will then cause the characteristic to be updated, in a loop).
The rationale behind this is that the BLE device I'm integrating with has a special custom characteristic, to which we can send different commands and then listen for data back.
I've read up lots about chaining commands using RxBLE, but none seem to address my particular query, which is how to send a command back to the device on observing a change notification (since the connection itself seems to be out of scope by the time we get to the observable block). What is the "Rx Way" of doing this?
For clarity, this is the entire flow of my BLE service:
scan for devices with a filter on our custom characteristic
connect to a found device
read a couple of standard characteristics (strings), and store these in our data model
if and only if one of the characteristics matches one of an array of strings, proceed to 5. otherwise, dispose of the connection.
subscribe to our custom "control" characteristic ("CC") for change notifications
send command 1 to CC. this should trigger answer 1 to be set in CC, so our handler is called
perform some calculations on answer 1 and save to our model. send command 2 (which includes these modified values, so we can't determine this at compile time) to CC. this should trigger answer 2 in CC.
on receiving answer 2, send command 3, which should trigger answer 3.
on reciving answer 3, parse into an int value. if answer 3 == 0, dispose of the connection - we are done.
answer 3 > 0, so send command 4. this will trigger answer 4.
perform some calculations on answer 4 and store the results in our model
then send command 5, which will actually trigger answer 3 (both commands 5 and 3 trigger answer 3). since we are already subscribed to answer 3, this takes us back to step 9. above - we keep looping until answer 3 is 0 (ie. we have saved all the data).
Edit: I was loathe to share code, as I'm well aware there is no possible way the following will work - but I'm hoping it describes what I'm trying to do even if the syntax won't even compile:
connectedDevice.connectionDisposable = connectedDevice.getRxDevice().establishConnection(false)
.observeOn(AndroidSchedulers.mainThread())
.flatMapSingle(rxBleConnection -> rxBleConnection.readCharacteristic(BATTERY_CHARACTERISTIC_UUID))
.doOnNext(bytes -> {
//store the battery info in our model here
})
.flatMapSingle(rxBleConnection -> rxBleConnection.readCharacteristic(SERIAL_NUMBER_CHARACTERISTIC_UUID))
.doOnNext(bytes -> {
//store the serial number info in our model here
//TODO: how do we only proceed to the subscription if serialNumber is correct?
}
)
.flatMap(rxBleConnection -> rxBleConnection.setupNotification(CUSTOM_CHARACTERISTIC_UUID))
.doOnNext(notificationObservable -> {
// Notification has been set up
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_1); //we can't do this because rxBleConnection is out of scope!
})
.flatMap(notificationObservable -> notificationObservable) // <-- Notification has been set up, now observe value changes.
.subscribe(
bytes -> {
// Given characteristic has been changes, here is the value.
switch(commandFromBytes(bytes)){
case answer1:
int newCommand = doSomethingWith(bytes);
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_2 + newCommand);
break;
case answer2:
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_3);
break;
case answer3:
if(bytes <= 0){
connectedDevice.connectionDisposable.dispose();
}
else{
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_4);
}
break;
case answer4:
doSomethingLongWindedWith(bytes);
//then
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_5);
//command 5 will cause answer3 to be notified, so we loop back above
break;
}
},
throwable -> {
// Handle an error here.
}
);
Edit 2: after playing bracket tango for a bit, I think I'm close to a solution here:
connectedDevice.connectionDisposable = connectedDevice.getRxDevice().establishConnection(false)
.observeOn(AndroidSchedulers.mainThread())
.flatMapSingle(rxBleConnection -> rxBleConnection.readCharacteristic(BATTERY_CHARACTERISTIC_UUID)
.doOnNext(bytes -> {
connectedDevice.setBatLevel(bytes);
})
.flatMapSingle(rxBleConnection2 -> rxBleConnection.readCharacteristic(SERIAL_NUMBER_CHARACTERISTIC_UUID))
.doOnNext(bytes -> {
connectedDevice.setSerialNum(bytes);
//we also notify a singleton listener here
}
)
.flatMap(rxBleConnection3 -> {
if (serialNumberIsCorrect(connectedDevice.getSerialNum())) {
rxBleConnection.setupNotification(CUSTOM_CHARACTERISTIC_UUID).subscribe(
bytes -> {
// Given characteristic has been changes, here is the value.
switch (commandFromBytes(bytes)) {
case answer1:
int newCommand = doSomethingWith(bytes);
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_2 + newCommand);
break;
case answer2:
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_3);
break;
case answer3:
if (bytes <= 0) {
//we also notify a singleton listener here
connectedDevice.connectionDisposable.dispose();
} else {
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_4);
}
break;
case answer4:
doSomethingLongWindedWith(bytes);
//then
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_5);
//command 5 will cause answer3 to be notified, so we loop back above
break;
}
},
throwable -> {
// Handle an error here.
}
);
} else {
connectedDevice.connectionDisposable.dispose();
}
}
.doOnNext(notificationObservable -> {
// Notification has been set up
if (serialNumberIsCorrect(connectedDevice.getSerialNum())) {
rxBleConnection.writeCharacteristic(CUSTOM_CHARACTERISTIC_UUID, COMMAND_1);
}
})
));
The best approach, according to this Jake Wharton's talk would be to construct an Observable that would emit just values that are needed for updating your model.
(example in Kotlin)
We could have these outputs of the Observable:
sealed class ConnectionEvent {
object CloseConnection : ConnectionEvent() // dummy event to notify when the connection can be closed
data class SerialNumber(val byteArray: ByteArray) : ConnectionEvent()
data class BatteryLevel(val byteArray: ByteArray) : ConnectionEvent()
data class Answer4(val byteArray: ByteArray) : ConnectionEvent()
}
And the whole flow could look like this:
bleDevice.establishConnection(false)
.flatMap { connection ->
val batteryLevelSingle = connection.readCharacteristic(batteryLevelCharUuid).map { ConnectionEvent.BatteryLevel(it) as ConnectionEvent }
val serialNumberSingle = connection.readCharacteristic(serialNumberCharUuid).map { ConnectionEvent.SerialNumber(it) }.cache() // cache as the output will be used by the continuation observable as well and we do not want to re-read the serial number
val continuationObservable: Observable<ConnectionEvent> = serialNumberSingle // continuation observable will work if the serial number matches
.flatMapObservable {
when {
it != matchingSerialNumber -> Observable.just(ConnectionEvent.CloseConnection as ConnectionEvent) // close connection if serial does not match
else -> createContinuationObservable(connection) // create flow for getting more data via additional writes and notifications
}
}
Observable.concat( // the actual flow of the whole connection
batteryLevelSingle.toObservable(), // we are starting with getting the battery level and emitting it
serialNumberSingle.toObservable(), // we are getting the serial number and emitting it
continuationObservable // if the serial number matches we continue with notifications and getting more data. otherwise CloseConnection
)
}
.takeWhile { it != ConnectionEvent.CloseConnection } // if the connection is to be closed -> unsubscribe
.subscribe(
{ connectionEvent ->
when(connectionEvent) {
is ConnectionEvent.SerialNumber -> { /* Update model */ }
is ConnectionEvent.BatteryLevel -> { /* Update model */ }
is ConnectionEvent.Answer4 -> { /* Update model */ }
}
},
{ /* handle errors */ }
)
where the write/notification dance is:
private fun createContinuationObservable(connection: RxBleConnection): Observable<ConnectionEvent> {
return connection.setupNotification(customCharUuid)
.flatMap { ccNotifications ->
ccNotifications.flatMap {
when (answerFromBytes(it)) {
answer1 -> connection.writeCharacteristic(customCharUuid, command2FromAnswer1Bytes(it)).ignoreEmissions()
answer2 -> connection.writeCharacteristic(customCharUuid, command3).ignoreEmissions()
answer3 -> when (it.isEmpty()) {
true -> Observable.just(ConnectionEvent.CloseConnection)
else -> connection.writeCharacteristic(customCharUuid, command4).ignoreEmissions()
}
answer4 -> connection.writeCharacteristic(customCharUuid, command5).ignoreEmissions()
.startWith(Observable.just(ConnectionEvent.Answer4(it)))
else -> Observable.error(Exception("Unexpected answer! => ${answerFromBytes(it)}"))
}
}
.startWith(connection.writeCharacteristic(customCharUuid, command1).ignoreEmissions()) // initiate with the command1
}
}
I have used an extension function for more clarity:
fun Single<ByteArray>.ignoreEmissions() = this.toCompletable().toObservable<ConnectionEvent>()
Edit:
I have changed the code a bit to get rid of CloseConnection event and leverage the completions of the observables. So now the outputs look like this:
sealed class ConnectionEvent {
data class SerialNumber(val byteArray: ByteArray) : ConnectionEvent()
data class BatteryLevel(val byteArray: ByteArray) : ConnectionEvent()
data class Answer4(val byteArray: ByteArray) : ConnectionEvent()
}
The main flow:
bleDevice.establishConnection(false)
.map { connection ->
val batteryLevelSingle = connection.readCharacteristic(batteryLevelCharUuid).map { ConnectionEvent.BatteryLevel(it) as ConnectionEvent }
val serialNumberSingle = connection.readCharacteristic(serialNumberCharUuid).map { ConnectionEvent.SerialNumber(it) }.cache() // cache as the output will be used by the continuation observable as well and we do not want to re-read the serial number
val continuationObservable: Observable<ConnectionEvent> = serialNumberSingle // continuation observable will work if the serial number matches
.flatMapObservable {
if (it == matchingSerialNumber) createContinuationObservable(connection) // create flow for getting more data via additional writes and notifications
else Observable.empty() // do not continue if serial number does not match
}
Observable.concat( // the actual flow of the whole connection
batteryLevelSingle.toObservable(), // we are starting with getting the battery level and emitting it
serialNumberSingle.toObservable(), // we are getting the serial number and emitting it
continuationObservable // if the serial number matches we continue with notifications and getting more data. otherwise CloseConnection
)
}
.publish {
// create a Completable from the above Observable.concat()
val dataDownloadCompletable = it.take(1) // take the first emission (there will be only one)
.flatMapCompletable { it.ignoreElements() } // and wait until the first emission completes
it.takeUntil(dataDownloadCompletable.toObservable<Any>()) // when dataDownloadCompletable completes —> unsubscribe from the upstream, mainly .establishConnection() to close it
}
.flatMap { it } // unwrap the above flow
.subscribe(
{ connectionEvent ->
when (connectionEvent) {
is ConnectionEvent.SerialNumber -> { /* Update model */ }
is ConnectionEvent.BatteryLevel -> { /* Update model */ }
is ConnectionEvent.Answer4 -> { /* Update model */ }
}
},
{ /* handle errors */ }
)
Write/notification part:
private fun createContinuationObservable(connection: RxBleConnection): Observable<ConnectionEvent> {
return connection.setupNotification(customCharUuid)
.flatMap { ccNotifications ->
ccNotifications.map { Pair(answerFromBytes(it), it) } // map every response to a pair of <answer, bytes>
.startWith(connection.writeCharacteristic(customCharUuid, command1).ignoreEmissions()) // and start with writing command1 to initiate the data exchange
}
.takeWhile { (answer, bytes) -> !(answer == answer3 && bytes.isEmpty()) } // end the createContinuationObservable on the first answer3 with an empty bytes
.flatMap<ConnectionEvent> { (answer, bytes) ->
when (answer) {
answer1 -> connection.writeCharacteristic(customCharUuid, command2FromAnswer1Bytes(bytes)).ignoreEmissions()
answer2 -> connection.writeCharacteristic(customCharUuid, command3).ignoreEmissions()
answer3 -> connection.writeCharacteristic(customCharUuid, command4).ignoreEmissions()
answer4 -> Observable.just(ConnectionEvent.Answer4(bytes)) // when answer4 is received emit actionable item to update the model
.concatWith(connection.writeCharacteristic(customCharUuid, command5).ignoreEmissions()) // and send the next command5
else -> Observable.error(Exception("Unexpected answer! => $answer"))
}
}
}
And the extension:
fun <T> Single<ByteArray>.ignoreEmissions() = this.toCompletable().toObservable<T>()
I'm currently trying to use rxandroidble in order to replace the native BLE API of Android of one of our app.
How to disable a notification? I'm able to enable it with the sample code, this one:
device.establishConnection(context, false)
.flatMap(rxBleConnection -> rxBleConnection.setupNotification(characteristicUuid))
.doOnNext(notificationObservable -> { // OK })
.flatMap(notificationObservable -> notificationObservable)
.subscribe(bytes -> { // OK });
But in my product I have a use case where I have to disable / enable the notification(s) on demand.
Plus, I tried to directly unsubscribe / reconnect instead of disable / enable the notification but the unsubscribe command is never executed apparently, my hypothesis is because I have a high throughput (my device notifies at 300 - 400Hz), is it plausible?
(I know that BLE is not the most appropriate technology for high throughput but it's for R&D purpose here :) )
Thanks for your help!
Enabling notifications happens whenever the Observable from RxBleConnection.setupNotification() will be subscribed. To disable the notification one must unsubscribe from the above subscription.
There are several ways in which it can be coded. One of them is:
final RxBleDevice rxBleDevice = // your RxBleDevice
final Observable<RxBleConnection> sharedConnectionObservable = rxBleDevice.establishConnection(this, false).share();
final Observable<Boolean> firstNotificationStateObservable = // an observable that will emit true when notification should be enabled and false when disabled
final UUID firstNotificationUuid = // first of the needed UUIDs to enable / disable
final Subscription subscription = firstNotificationStateObservable
.distinctUntilChanged() // to be sure that we won't get more than one enable commands
.filter(enabled -> enabled) // whenever it will emit true
.flatMap(enabled -> sharedConnectionObservable // we take the shared connection
.flatMap(rxBleConnection -> rxBleConnection.setupNotification(firstNotificationUuid)) // enable the notification
.flatMap(notificationObservable -> notificationObservable) // and take the bytes
.takeUntil(firstNotificationStateObservable.filter(enabled1 -> !enabled1)) // and we are subscribing to this Observable until we want to disable - note that only the observable from sharedConnectionObservable will be unsubscribed
)
.subscribe(
notificationBytes -> { /* handle the bytes */ },
throwable -> { /* handle exception */ }
);
Note that in the above example the connection will be closed whenever the last subscription to sharedConnectionObservable will end.
To enable / disable different characteristics you can copy and paste the above code with different Observable<Boolean> as enable / disable inputs and different UUID's.
Kotlin
In kotlin, Use dispose() to disable the notification.
#ENABLE NOTIFICATION
val result = device.establishConnection(false)
.flatMap(rxBleConnection -> rxBleConnection.setupNotification(characteristicUuid))
.doOnNext(notificationObservable -> {
// Notification has been set up
})
.flatMap(notificationObservable -> notificationObservable) // <-- Notification has been set up, now observe value changes.
.subscribe(
bytes -> {
// Given characteristic has been changes, here is the value.
},
throwable -> {
// Handle an error here.
}
);
#DISABLE NOTIFICATION
result.dispose()
Tried to unsubscribe but it didn't work, still not sure which one is best dispose() or unsubscribe()