Why is my data is not writing to Firebase - App crashes due to setObjectForKey: key cannot be nil - ios

Question

for the past two weeks i've been having a struggle to write data to firebase, although the tutorials seem so simple :/....My app has a view controller and a tableview controller. users can add an event Title, event date and description (strings) and add a picture as well. Whenever i try to run the simulator it crashes on me! See code below. Please please help me out this is really getting frustrating.. Even if I place breakpoints in the code on top it crashes.. If someone can help me in a chat that would be awesome or maybe send the file to cause its been too long seriously I need an answer so i understand the problem.
import UIKit
import Firebase
import FirebaseDatabaseUI
class EventViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
//outlets for text & image
#IBOutlet weak var photoImageView: UIImageView!
#IBOutlet weak var eventName: UITextField!
#IBOutlet weak var eventDate: UITextField!
#IBOutlet weak var eventDes: UITextView!
//Database connection
let rootref = FIRDatabase().reference()
var imagePicker: UIImagePickerController = UIImagePickerController()
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
#IBAction func submitEvent(sender: AnyObject) {
let name = eventName.text
let date = eventDate.text
let text = eventDes.text
var data: NSData = NSData()
var user = NSDictionary()//declare here
if let image = photoImageView.image {
data = UIImageJPEGRepresentation(image,0.1)!
}
let base64String = data.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
if let unwrappedName = name , unwrappedDate = date, unwrappedText = text{
//use your declared dictionary
user = ["name":unwrappedName, "date":unwrappedDate, "text":unwrappedText, "photoBase64":base64String]
}
//Add firebase child node
//let event = FIRDatabase().reference().child(name!)
//Do not create one more reference to database
rootref.child(name!)
rootref.child(name!).setValue(user)
navigationController?.popViewControllerAnimated(true)
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
view.endEditing(true)
super.touchesBegan(touches, withEvent: event)
}
//UIImagePickerControllerDelegate methods
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
imagePicker.dismissViewControllerAnimated(true, completion: nil)
photoImageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage
}
func imagePickerControllerDidCancel(picker: UIImagePickerController) {
dismissViewControllerAnimated(true, completion: nil)
}
#IBAction func addPicture(sender: AnyObject) {
if(UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera)) {
imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = .Camera
presentViewController(imagePicker, animated: true, completion: nil)
} else {
imagePicker.allowsEditing = false
imagePicker.sourceType = .PhotoLibrary
imagePicker.delegate = self
presentViewController(imagePicker, animated: true, completion:nil)
}
}
}