Uploading Image to Firebase Storage and Database

For Updated Firebase Version And Swift 4.2 Code :

 func uploadMedia(completion: @escaping (_ url: String?) -> Void) {

    let storageRef = Storage.storage().reference().child("\(Auth.auth().currentUser?.uid ?? "").png")
    if let uploadData = self.imgUploadView.image?.jpegData(compressionQuality: 0.5) {
        storageRef.putData(uploadData, metadata: nil) { (metadata, error) in
            if error != nil {
                print("error")
                completion(nil)
            } else {

                storageRef.downloadURL(completion: { (url, error) in

                    print(url?.absoluteString)
                    completion(url?.absoluteString)
                })

              //  completion((metadata?.downloadURL()?.absoluteString)!))
                // your uploaded photo url.


            }
        }
    }
}

Organize your upload and save funcs like this:

func uploadMedia(completion: @escaping (_ url: String?) -> Void) { 
    let storageRef = FIRStorage.storage().reference().child("myImage.png")
    if let uploadData = UIImagePNGRepresentation(self.myImageView.image!) {
        storageRef.put(uploadData, metadata: nil) { (metadata, error) in
            if error != nil {
                print("error")
                completion(nil)
            } else {
                completion((metadata?.downloadURL()?.absoluteString)!)) 
                // your uploaded photo url.
            }
       }
 }

Next just connect to FIRDatabase and save it to your node.

 @IBAction func addPost(_ sender: Any) {
     if self.titleText.text   != "" && self.authorText.text != "" 
        && self.mainText.text != "" && self.dateText.text   != "" {
     
     uploadMedia() { url in 
          guard let url = url else { return }
          ref?.child("Posts").childByAutoId().setValue([
                                "Title"      : titleText.text,
                                "Article"    : mainText.text, 
                                "Author"     : authorText.text, 
                                "Date"       : dateText.text, 
                                "myImageURL" : url
                                ])
     }
 }

You can also look at my answer about uploading data and saving URL's to database

100% working tested just one add function

 //MARK: - Upload image
func uploadImage(_ image: UIImage){
 
    let imageName:String = String("\(CurrentTimeStampInSecond).png")
    
    let storageRef = Storage.storage().reference().child("profilePic").child(imageName)
    let compressImage = HelperFunction.helper.resizeImage(image: image)
    if let uploadData = UIImagePNGRepresentation(compressImage){
        storageRef.putData(uploadData, metadata: nil
            , completion: { (metadata, error) in
                if error != nil {
                    print("error")
                     self.stopAnimating()
                    showAlertWithTitleWithMessage(message: "Please try again later")
                    return
                }else{
                    self.stopAnimating()
                }
                
                let strPic:String = (metadata?.downloadURL()?.absoluteString)!
                               
                print(metadata)
                //self.imagePath = (metadata?.downloadURL()?.absoluteString)!
                //self.sendMessageOnServer()
                print("\n\n\n\n\n\n ===download url : \(strPic)")
                   
        })
        
    }
}