This error keeps popping up in my code and I need to know what to do about it. I'm still a newbie, so if you want to give me tips on how to code in Swift, I'll be happy to see them
Use of unresolved identifier 'self'
Here's my code:
import ReachabilitySwift
class ReachabilityManager: NSObject {
static let shared = ReachabilityManager()
}
var isNetworkAvailable : Bool {
return reachabilityStatus != .notReachable
}
var reachabilityStatus: Reachability.NetworkStatus = .notReachable
let reachability = Reachability()!
func reachabilityChanged(notification: Notification) {
let reachability = notification.object as! Reachability
switch reachability.currentReachabilityStatus {
case .notReachable:
debugPrint("Network became unreachable")
case .reachableViaWiFi:
debugPrint("Network reachable through WiFi")
case .reachableViaWWAN:
debugPrint("Network reachable through Cellular Data")
}
}
func startMonitoring() {
NotificationCenter.default.addObserver(self,selector: #selector(self.reachabilityChanged),name: ReachabilityChangedNotification,object: reachability)
do{
try reachability.startNotifier()
} catch {
debugPrint("Could not start reachability notifier")
}
}
This situation happens when self is not defined, please make sure that you are trying to add startMonitoring() function to a class, extension or struct's scope.
Related
i have a list of music at my firebase real time database and i am retriving them but i have 1000 musics data and i want to show loader when i reading data and stop loader when if there is a error(internet connection, or something else) or reading completed.
when i turn off the internet i couldn't get the data and can't stop loader to show error alert like there is no internet connection.
please help me how to handle that problem.
here is my code
didload function called from viewdidload()
private var musicArray = [ItemModal]() {
didSet {
view?.updateTableView()
}
}
func didLoad() {
view?.showLoader()
getAllMusics { ItemModal in
self.musicArray = ItemModal
self.view?.hideLoader()
}
}
func getAllMusics(completion: #escaping ([ItemModal]) -> Void) {
var musicArray = [ItemModal]()
ref.child("music").observeSingleEvent(of: .value) { snapshot in
let enumerator = snapshot.children
while let rest = enumerator.nextObject() as? DataSnapshot {
guard let data = try? JSONSerialization.data(withJSONObject: rest.value as Any, options: []) else { return }
if let itemModal = try? JSONDecoder().decode(ItemModal.self, from: data) {
musicArray.append(itemModal)
}
}
completion(musicArray)
}
}
You can use reachability function by using https://github.com/ashleymills/Reachability.swift. To get to notify when the internet is turned off, you can implement reachabilityChanged Notification. In the selector method of reachabilityChanged, you can hide the loader.
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(reachabilityChanged), name: .reachabilityChanged)
}
#objc func changed() {
if reachability?.isReachable {
//Continue success implementation
} else {
view?.hideLoder
//Implement Error handling
}
}
ReplayKit has really been frustrating me recently. For some reason
RPScreenRecorder.shared().startCapture(handler: { (sample, bufferType, error) in
does not actually work when I call it because I have a print() statement inside it and it is never called.
My code in the ViewController is:
import UIKit
import AVFoundation
import SpriteKit
import ReplayKit
import AVKit
class ViewController: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate, RPPreviewViewControllerDelegate {
var assetWriter:AVAssetWriter!
var videoInput:AVAssetWriterInput!
func startRecording(withFileName fileName: String) {
if #available(iOS 11.0, *)
{
assetWriter = try! AVAssetWriter(outputURL: fileURL, fileType:
AVFileType.mp4)
let videoOutputSettings: Dictionary<String, Any> = [
AVVideoCodecKey : AVVideoCodecType.h264,
AVVideoWidthKey : UIScreen.main.bounds.size.width,
AVVideoHeightKey : UIScreen.main.bounds.size.height
];
videoInput = AVAssetWriterInput (mediaType: AVMediaType.video, outputSettings: videoOutputSettings)
videoInput.expectsMediaDataInRealTime = true
assetWriter.add(videoInput)
print("HERE")
RPScreenRecorder.shared().startCapture(handler: { (sample, bufferType, error) in
print("RECORDING")
}
}
}
func stopRecording(handler: #escaping (Error?) -> Void)
{
if #available(iOS 11.0, *)
{
RPScreenRecorder.shared().stopCapture
{ (error) in
handler(error)
self.assetWriter.finishWriting
{
print("STOPPED")
}
}
}
}
"HERE" is printed, but not "RECORDING"
[p.s. sorry for bad formatting in code, I'm sure you'll understand :)]
I have also tried a different method:
let recorder = RPScreenRecorder.shared()
recorder.startRecording{ [unowned self] (error) in
guard error == nil else {
print("There was an error starting the recording.")
return
}
print("Started Recording Successfully")
}
and to stop the recording...
recorder.stopRecording { [unowned self] (preview, error) in
print("Stopped recording")
guard preview != nil else {
print("Preview controller is not available.")
return
}
onGoingScene = true
preview?.previewControllerDelegate = self
self.present(preview!, animated: true, completion: nil)
}
This method does not stop when I call the recorder.stopRecording() function, "Stopped recording" is never called.
Can someone please help me because this is really frustrating me, how can you PROPERLY use ReplayKit to record your screen in iOS 11? I have searched all over the internet and none of the methods work for me, I don't why. P.S. I have the necessary permission keys in my Info.plist.
Thanks
A huge reminder that ReplayKit doesn't work in simulator. I wasted hours on the exact same issue until realized that ReplayKit will never trigger startCapture handler because it never records in simulator.
Well there are quite few possible causes for this issue.
Some of them are here:
Your Replay kit Shared Recorder might be crashed, For that you can restart your device and check again.
There might be printable issue in your replay kit. For that kindly conform to the RPScreenRecorderDelegateProtocol and add Recording Changes
screenRecorder:didStopRecordingWithPreviewViewController:error:
method to your class and check if any error shows up in this method.
I am trying to detect is the Bluetooth of the user's iPhone On or Off. If it is Off I want to send a notification to the user to turn it On.
So far I have done this:
import CoreBluetooth
class ViewController: UIViewController, CLLocationManagerDelegate,AVCaptureMetadataOutputObjectsDelegate,CBManager {
var myBTManager = CBPeripheralManager(delegate: self, queue: nil, options: nil)
}
func peripheralManagerDidUpdateState(peripheral: CBPeripheralManager!) {
print(#function)
if peripheral.state == CBManagerState.poweredOn {
print("Broadcasting...")
// myBTManager!.startAdvertising(_broadcastBeaconDict)
} else if peripheral.state == CBManagerState.poweredOff {
print("Stopped")
myBTManager!.stopAdvertising()
} else if peripheral.state == CBManagerState.unsupported {
print("Unsupported")
} else if peripheral.state == CBManagerState.unauthorized {
print("This option is not allowed by your application")
}
}
But as You can see from the picture, something is wrong.
Would you please help me how to fix this issue, I am new to swift and CoreBluetooth technology. I am also using Reachability for detecting the Wi-Fi connection, so if it also works for Bluetooth, I would prefer to use Reachability then.
You should be implementing the protocol CBPeripheralManagerDelegate, so replace CBManager in your class definition line with CBPeripheralManagerDelegate.
In Swift 3, the signature of peripheralManagerDidUpdateState is now:
func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager)
You can't initialize the CBPeripheralManager at class creation time since self is only available after the class has been initialized. Instead, make your property:
var myBTManager: CBPeripheralManager?
and initialize it in viewDidLoad:
override func viewDidLoad() {
...
myBTManager = CBPeripheralManager(delegate: self, queue: nil, options: nil)
...
}
You can use the CBCentralMangerDelegate method:
public func centralManager(_ central: CBCentralManager, willRestoreState dict: [String : Any]) {
if central.state == .poweredOn {
//Bluetooth is on
} else if central.state == .poweredOff {
//Bluetooth is off
}
}
What I am trying to accomplish is posting a notification through NSNotificationCenter's default center. This is being done within a closure block after making a network call using Alamofire. The problem I am having is that a class that should be responding to a posted notification isn't receiving such notification.
My ViewController simply creates a First object that get's things moving:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let first = First()
}
}
My First class creates and instance of a Second class and adds itself as an observer to my NSNotificationCenter. This is the class that can't seem to get the notification when the notification is posted.
class First : NSObject {
let second = Second()
override init(){
super.init()
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(First.gotDownloadNotification(_:)), name: "test", object: nil)
second.sendRequest()
}
// NOT REACHING THIS CODE
func gotDownloadNotification(notification: NSNotification){
print("Successfully received download notification from Second")
}
}
My Second class is what makes the network call through my NetworkService class and posts a notification in a closure once the request is successful and complete.
class Second : NSObject {
func sendRequest(){
let networkService = NetworkService()
networkService.downloadFile() { statusCode in
if let statusCode = statusCode {
print("Successfully got a status code")
// Post notification
NSNotificationCenter.defaultCenter().postNotificationName("test", object: nil)
}
}
}
}
Finally, my NetworkService class is what makes a network call using Alamofire and returns the status code from the response through a closure.
class NetworkService : NSObject {
func downloadFile(completionHandler: (Int?) -> ()){
Alamofire.download(.GET, "https://www.google.com") { temporaryURL, response in
let fileManager = NSFileManager.defaultManager()
let directoryURL = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
let pathComponent = response.suggestedFilename
return directoryURL.URLByAppendingPathComponent(pathComponent!)
}
.response { (request, response, _, error) in
if let error = error {
print("File download failed with error: \(error.localizedDescription)")
completionHandler(nil)
} else if let response = response{
print("File downloaded successfully")
// Pass status code through completionHandler to Second
completionHandler(response.statusCode)
}
}
}
}
The output after execution is:
File downloaded successfully
Successfully got a status code
From this output I know the download was successful and Second got the status code from the closure and posted a notification right after.
I believe that I have tried resolving most other suggestions on Stack Overflow related to not receiving notifications such as objects not being instantiated before notification is posted or syntax of either adding an observer or posting a notification.
Does anyone have any idea why the posted notification is not being received in the First class?
Since there is a direct relationship between First and Second the protocol/delegate pattern is the better way to notify. Even better with this pattern and you don't have to take care of unregistering the observer. NSNotificationCenter is supposed to be used only if there is no relationship between sender and receiver.
And basically the thread doesn't matter either.
protocol SecondDelegate {
func gotDownloadNotification()
}
class Second : NSObject {
var delegate : SecondDelegate?
init(delegate : SecondDelegate?) {
self.delegate = delegate
}
func sendRequest(){
let networkService = NetworkService()
networkService.downloadFile() { statusCode in
if let statusCode = statusCode {
print("Successfully got a status code")
// Post notification
self.delegate?.gotDownloadNotification()
}
}
}
}
class First : NSObject, SecondDelegate {
let second : Second
override init(){
super.init()
second = Second(delegate:self)
second.sendRequest()
}
func gotDownloadNotification(){
print("Successfully received download notification from Second")
}
}
im working on an iphone app for iOS 8.1 that works with core audio to generate frequencies and adjust intensities. In the view controller that i generate the frequencies i need to control if the headphones are plugged out in some moment, i'm already controlling if headphones are connected before proceed to my frequencies generator view with the following function:
- (BOOL)isHeadsetPluggedIn {
AVAudioSessionRouteDescription* route = [[AVAudioSession sharedInstance] currentRoute];
for (AVAudioSessionPortDescription* desc in [route outputs]) {
if ([[desc portType] isEqualToString:AVAudioSessionPortHeadphones])
return YES;
}
return NO;
}
this function is in C because im working with core-audio to generate the frequencies, but in the view controllers im working with swift so a need a way to implement a listener to detect the headphones plug-out event and return to the user to the previous view, i don't know if i can use my function isHeadsetPluggedin() with an event listener or i should make a new one.
In my MenuViewController i control if the headphones are plugged in using the following function:
func isHeadsetPluggedIn() -> Bool {
return freqController.isHeadsetPluggedIn();
}
In Swift 4
func activateHeadPhonesStatus(){
NotificationCenter.default.addObserver(self, selector: #selector(audioRouteChangeListener(_:)), name: AVAudioSession.routeChangeNotification, object: nil)
}
#objc func audioRouteChangeListener(_ notification:Notification) {
guard let userInfo = notification.userInfo,
let reasonValue = userInfo[AVAudioSessionRouteChangeReasonKey] as? UInt,
let reason = AVAudioSession.RouteChangeReason(rawValue:reasonValue) else {
return
}
switch reason {
case .newDeviceAvailable:
let session = AVAudioSession.sharedInstance()
for output in session.currentRoute.outputs where output.portType == AVAudioSession.Port.headphones {
headphonesConnected = true
print("headphone plugged in")
break
}
case .oldDeviceUnavailable:
if let previousRoute =
userInfo[AVAudioSessionRouteChangePreviousRouteKey] as? AVAudioSessionRouteDescription {
for output in previousRoute.outputs where output.portType == AVAudioSession.Port.headphones {
headphonesConnected = false
print("headphone pulled out")
break
}
}
default: ()
}
}
You can track the route changes by observing AVAudioSessionRouteChangeNotification notification.
//Observe for route changing notification
[[NSNotificationCenter defaultCenter]addObserver:self selector:#selector(handleRouteChange:) name:AVAudioSessionRouteChangeNotification object:[AVAudioSession sharedInstance]];
-(void)handleRouteChange:(NSNotification *)notif
{
NSDictionary *dict = notif.userInfo;
AVAudioSessionRouteDescription *routeDesc = dict[AVAudioSessionRouteChangePreviousRouteKey];
AVAudioSessionPortDescription *prevPort = [routeDesc.outputs objectAtIndex:0];
if ([prevPort.portType isEqualToString:AVAudioSessionPortHeadphones]) {
//Head phone removed
}
}
This article worked for me. There is also a GitHub repo with solution. If you don't want to read, here is my code:
Put this in your INIT method:
self.session = AVAudioSession.sharedInstance()
let currentRoute = self.session.currentRoute
if currentRoute.outputs.count != 0 {
for description in currentRoute.outputs {
if description.portType == AVAudioSessionPortHeadphones {
print("headphone plugged in")
} else {
print("headphone pulled out")
}
}
} else {
print("requires connection to device")
}
NSNotificationCenter.defaultCenter().addObserver(
self,
selector: #selector(YOUR_VIEW_CONTROLLER_OR_VIEW.audioRouteChangeListener(_:)),
name: AVAudioSessionRouteChangeNotification,
object: nil)
And put this anywhere in your class:
dynamic private func audioRouteChangeListener(notification:NSNotification) {
let audioRouteChangeReason = notification.userInfo![AVAudioSessionRouteChangeReasonKey] as! UInt
switch audioRouteChangeReason {
case AVAudioSessionRouteChangeReason.NewDeviceAvailable.rawValue:
print("headphone plugged in")
case AVAudioSessionRouteChangeReason.OldDeviceUnavailable.rawValue:
print("headphone pulled out")
default:
break
}
}
Take care!