Can any one help me to solve this error using Swift - swift

Question

would you please help me to solve this error .I'am trying to download an Image From Firebase Database, this is my code and I put a snapshot for the error . ThanksThis is a snapshot for the error in Xcode
import UIKit
import FirebaseDatabase
class ViewController: UIViewController , UITableViewDataSource , UITableViewDelegate {
#IBOutlet weak var tableView: UITableView!
var ref:FIRDatabaseReference?
var Handle:FIRDatabaseHandle?
var myClass = [Post]()
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
ref=FIRDatabase.database().reference()
Handle = ref?.child("Posts").observe(.childAdded, with: { (snapshot) in
let post = snapshot.valueInExportFormat()
for url in post! as! [Post] { // Error Here
self.myClass.append(url)
self.tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
return myClass.count
}
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)as? TableViewCell{
cell.MyImage.alpha = 0
cell.textLabel?.text = PostData[indexPath.row]
DispatchQueue.main.async(execute: {
let imgurl = URL(string : self.myClass [(indexPath as NSIndexPath).row].url)
let imgdata = NSData(contentsOf: imgurl!)
cell.MyImage.image = UIImage(data: imgdata as! Data)
UIView.animate(withDuration: 0.5, animations: {
cell.MyImage.alpha = 1
})
})
return cell
} else {
let cell = TableViewCell()
DispatchQueue.main.async(execute: {
let imgurl = URL(string : self.myClass [(indexPath as NSIndexPath).row].url)
let imgdata = NSData(contentsOf: imgurl!)
cell.MyImage.image = UIImage(data: imgdata as! Data)
})
return cell
}
}
}
})
}

Answer 1

Sometimes simple is the way to go.
assume you have a Firebase structure
Planets
planet_4
some_text = "My post about Mars"
image_url = "images/mars.jpg"
planet_2
some_text = "My post about Venus"
image_url = "images/venus.jpg"
and suppose we want to load each text and image and display in a tableview. We can do it one of two ways, one at a time with .childAdded or all at once with .value. In this example, we'll walk through them one at a time.
let planetsRef = myRootRef.child("Planets")
planetsRef.observe(.childAdded, with: { snapshot in
let dict = snapshot.value as! [String: AnyObject]
let text = dict["text"]
let imageUrl = dict["image_url"]
// Create a reference to the file you want to download
let planetRef = storageRef.child(imageUrl) //storageRef is defined elsewhere
// Download in memory with a maximum allowed size
// of 1MB (1 * 1024 * 1024 bytes)
planetRef.dataWithMaxSize(1 * 1024 * 1024) { (data, error) -> Void in
if (error != nil) {
// Got an error so handle it
} else {
// Data for "images/some planet.jpg" is returned
// let planetImage: UIImage! = UIImage(data: data!)
// then add the text and the image to your dataSource array
// and reload your tableview.
}
})
})
This is not tested but will provide the general idea

Answer 2

Maybe you want:
for url in post! {
var wrappedPost = Post()
wrappedPost.url = url
... use wrappedPost for whatever you need a Post object for
}