 
         let possibleCameraInput: AnyObject?
         do {
-            possibleCameraInput = try AVCaptureDeviceInput(device: backCameraDevice!)
+            possibleCameraInput = try AVCaptureDeviceInput(device: backCameraDevice)
         } catch let error1 as NSError {
             error = error1
             possibleCameraInput = nil
         }
         let backCameraInput = possibleCameraInput as? AVCaptureDeviceInput
-        if captureSession.canAddInput(backCameraInput!) {
-            captureSession.addInput(backCameraInput!)
+        if captureSession.canAddInput(backCameraInput) {
+            captureSession.addInput(backCameraInput)
         }
 
         stillImageOutput = AVCaptureStillImageOutput()
-        if captureSession.canAddOutput(stillImageOutput!) {
+        if captureSession.canAddOutput(stillImageOutput) {
             stillImageOutput?.isHighResolutionStillImageOutputEnabled = true;
             stillImageOutput?.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG];
-            captureSession.addOutput(stillImageOutput!)
-        }
-        captureSession.sessionPreset = AVCaptureSession.Preset.photo
+            captureSession.addOutput(stillImageOutput)
+        }
+        captureSession.sessionPreset = AVCaptureSessionPresetPhoto
         setFlashModeToAuto(backCameraDevice!)
         beginSession()
     }

@objc protocol cameraDelegate{ func cameraFinished(_ controller: HappieCameraViewController) }

@objc(HappieCameraViewController) class HappieCameraViewController : UIViewController, AVCaptureFileOutputRecordingDelegate  {
    func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {

    }


    //MARK: Class Variables
    let captureSession = AVCaptureSession() //provides a UI context for capturing media

                try device.lockForConfiguration();

                if(flashState == 0){
                    if(backCameraDevice!.isFlashModeSupported(AVCaptureFlashMode.off)){
                        device.flashMode = AVCaptureFlashMode.off;
                        let image = UIImage(named: "camera_flash_off.png") as UIImage!
                        flashUIButton.setImage(image, for: UIControlState())
                    }
                    if(backCameraDevice!.isTorchModeSupported(AVCaptureTorchMode.off)){
                        device.torchMode = AVCaptureTorchMode.off;
                    }
                    flashState = 1;
                }

                else if(flashState == 1){
                    if(backCameraDevice!.isFlashModeSupported(AVCaptureFlashMode.auto)){
                        device.flashMode = AVCaptureFlashMode.auto;
                        let image = UIImage(named: "camera_flash_auto.png") as UIImage!
                        flashUIButton.setImage(image, for: UIControlState())
                    }
                    if(backCameraDevice!.isTorchModeSupported(AVCaptureTorchMode.off)){
                        device.torchMode = AVCaptureTorchMode.off;
                    }
                    flashState = 2
                }
                else if(flashState == 2){
                    if(backCameraDevice!.isFlashModeSupported(AVCaptureFlashMode.off)){
                        device.flashMode = AVCaptureFlashMode.off;
                        let image = UIImage(named: "camera_flash_on.png") as UIImage!
                        flashUIButton.setImage(image, for: UIControlState())
                    }
                    if(backCameraDevice!.isTorchModeSupported(AVCaptureTorchMode.on)){
                        device.torchMode = AVCaptureTorchMode.on;
                    }

                    flashState = 0;
