Index out of range for only last 2 values? - ios

Question

I am currently getting index out of range but this only happens after the first 3 items have been displayed successfully. I looked through the code and I still don't know where im going wrong. Index out of range happens only when trying to load text in the cells.
Log when method is called from viewdidload:
Description of indexPath: 0
Description of indexPath: 1
Description of indexPath: 2
Log when I press a button to load the rest of images:
Description of indexPath: 0
Description of indexPath: 1
Description of indexPath: 2
Description of indexPath: 3
Datasource method where indexpath is out of range:
//MARK: - tableview datasource methods
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
if arrayOfImgObj.count > 0 {
cell.imageView?.image = arrayOfImgObj[indexPath.row].imageTempt
print("Description of indexPath: ",indexPath.row)
cell.textLabel?.text = arrayOfUIDs[indexPath.row] // index out of range
} else {
print("\(arrayOfImgObj.count) not over 0 yet")
}
return cell
}
Method that is called when viewDidload:
//testing array
var arrayOfUIDs = User().users
func fetchAllUserFristImage() {
Database.database().reference().child("Posts").observe(.childAdded, with: {(snapshot) in
if (snapshot.value as? [String: AnyObject]) != nil {
let user = User()
user.id = snapshot.key
//testing array
self.arrayOfUIDs.append(snapshot.key)
print("\(String(describing: user.id)) <-- SHUD BE THE USERUID")
self.databaseRef = Database.database().reference()
let usersPostRef2 = self.databaseRef.child("Posts").child(user.id!)
usersPostRef2.observe(.value, with: {(postXSnapshots) in
if let postDictionary2 = postXSnapshots.value as? NSDictionary {
for (p) in postDictionary2 {
let posts = p.value as! NSDictionary
//to get back to where i was delete the below for i
for (i) in posts {
let imageUrlString = i.value as! NSDictionary
guard let postUrl = imageUrlString.value(forKey: "image1") else {return}
//below is ting from below
if postUrl != nil {
self.feedArray.append(Post(fetchedImageURL: postUrl as! String))
let imageUrlString = "\(postUrl)"
let imageUrl = URL(string: imageUrlString)!
print("\(imageUrl) this shud be img url's of posts")
let imageDataL = try! Data(contentsOf: imageUrl)
self.imageObject.img2 = UIImage(data: imageDataL)
let image1ToDisplay: UIImage = self.imageObject.img2!
self.arrayOfImgObj.append(forTable(imageTempt: image1ToDisplay))
} else {print("this user had no posts, was nil")}
}
}
}
})
}
//below shud stay same
DispatchQueue.main.async {
self.tableView.reloadData()
}
})
}
Edit:
I have changed teh code to only use one array of objects:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
if arrayOfImgObj.count > 0 {
cell.imageView?.image = arrayOfImgObj[indexPath.row].imageTempt
print("Description of indexPath: ",indexPath.row)
cell.textLabel?.text = arrayOfImgObj[indexPath.row].users[indexPath.row] // index out of range
} else {
print("\(arrayOfImgObj.count) not over 0 yet")
}
return cell
}
changing one line in the function to this:
self.arrayOfImgObj.append(forTable(imageTempt: image1ToDisplay, users: snapshot.key))
Thanks in advance!

Answer 1

Your problem is that you have two arrays:
arrayOfUIDs which has one entry for each user
arrayOfImgObj which has 0-n entries for each user (So, it is likely that the number of objects in this array will be greater than the number of objects in arrayOfUIDs.
You are basing your row count on the arrayOfImgObj, but then using the row number to index into arrayOfUIDs, which results in an array bounds exception.
It may well be more elegant to have table view section per userid, but if you want to put all of the rows in a single section I would suggest you use a single array of structs as your data model.
Use something like:
struct UserImage {
var userID: String
var image: UIImage
}
var tableData = [UserImage]()
Then as you fetch each image, create a new struct and put it in your array:
func fetchAllUserFristImage() {
Database.database().reference().child("Posts").observe(.childAdded, with: {(snapshot) in
if snapshot.value as? [String: AnyObject] != nil {
let user = snapshot.key
self.databaseRef = Database.database().reference()
let usersPostRef2 = self.databaseRef.child("Posts").child(user)
usersPostRef2.observe(.value, with: {(postXSnapshots) in
if let postDictionary2 = postXSnapshots.value as? [String:AnyObject] {
for (p) in postDictionary2 {
if let posts = p.value as? [String:AnyObject] {
//to get back to where i was delete the below for i
for (i) in posts {
if let imageUrlString = i.value as? [String:AnyObject], let postUrl = imageUrlString.["image1"] as? String {
self.feedArray.append(Post(fetchedImageURL: postUrl))
if let imageUrl = URL(string: postUrl), let imageDataL = try? Data(contentsOf: imageUrl), let image = UIImage(data: imageDataL) {
self.tableData.append(UserImage(userID: user, image: image))
} else {print("this user had no posts, was nil")}
}
}
}
}
}
})
//below shud stay same
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
})
}
Now, your cellForRow can be:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
cell.imageView?.image = tableData[indexPath.row].image
cell.textLabel?.text = tableData[indexPath.row].userID
return cell
}