Class has no initializers static let dataService (swift)
<p>dataservice.swift</p>

<p>class DataService    --> class data service has no initializers
static let dataService = DataService()   --> data service cannot be 
constructed because it has no accessible initializers </p>

<pre><code>class DataService {

static let dataService = DataService()

private var _BASE_REF = FIRDatabase.database().reference()
var fileUrl: String


var BASE_REF: FIRDatabaseReference {
    return _BASE_REF
}

var storageRef : FIRStorageReference {
    return FIRStorage.storage().reference()
    }


func SignUp(username: String, email: String, password: String, data: NSData) {

    FIRAuth.auth()?.createUserWithEmail(email, password: password, completion: { (user, error) in
        if let error = error {
            print(error.localizedDescription)
            return
        }
        let changeRequest = user?.profileChangeRequest()
        changeRequest?.displayName = username
        changeRequest?.commitChangesWithCompletion({ (error) in
            if let error = error {
                print(error.localizedDescription)
                return
            }

        })

        let filePath = "profileImage/\(user!.uid)"
        let metadata = FIRStorageMetadata()
        metadata.contentType = "image/jpeg"

        self.storageRef.child(filePath).putData(data, metadata: metadata, completion: { (metadata, error) in
            if let error = error {
                print("\(error.description)")
                return
            }

            self.fileUrl = (metadata?.downloadURLs! [0].absoluteString)!
            let changeRequestPhoto = user!.profileChangeRequest()
            changeRequestPhoto.photoURL = NSURL(string: self.fileUrl)
            changeRequestPhoto.commitChangesWithCompletion({ (error) in
                if let error = error {
                    print(error.localizedDescription)
                    return
                }else{
                    print("profile updated")

                }

            })
            let appDelegate: AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
            appDelegate.login()



        })
    })


}


}
</code></pre>