Receive Image from pointer - ios

Question

I have a pointer in my parse. The pointer tells me who uploaded the images. I am trying to retrieve the username and the profile picture of the uploader. To do that I have put query.includeKey("uploader") . Users are managed through the user class. and posts are managed in the posts class. To retrieve the images and names I have the below code.
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("newview", forIndexPath: indexPath) as! NewCollectionViewCell
let item = self.votes[indexPath.row]
// Display "initial" flag image
var initialThumbnail = UIImage(named: "question")
cell.postsImageView.image = initialThumbnail
if let pointer = item["uploader"] as? PFObject {
cell.userName!.text = item["username"] as? String
}
if let profile = item["uploader"] as? PFObject {
cell.profileImageView.loadInBackground({ (image:UIImage, error:NSError) -> Void in
if error != nil{
cell.profileImageView.image = image
}
})}
if let votesValue = item["votes"] as? Int
{
cell.votesLabel?.text = "\(votesValue)"
}
// Fetch final flag image - if it exists
if let value = item["imageFile"] as? PFFile {
cell.postsImageView.file = value
cell.postsImageView.loadInBackground({ (image: UIImage?, error: NSError?) -> Void in
if error != nil {
cell.postsImageView.image = image
}
})
}
return cell
}
However errors are happening saying that loadinbackround can't be invoked with an argument list of type (UIImage, NSError)->void. The strange part is that the error is only for the first part where I try to retrieve the images for the user. I am really stuck in this and want help. Is my pointer retrieving wrong? Thank you.
UPDATE 2
#IBOutlet weak var collectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
let query = PFQuery(className: "Posts")
query.includeKey("pointName")
query.findObjectsInBackgroundWithBlock{(question:[AnyObject]?,error:NSError?) -> Void in
if error == nil
{
if let allQuestion = question as? [PFObject]
{
self.votes = allQuestion
self.collectionView.reloadData()
}
}
}
// Wire up search bar delegate so that we can react to button selections
// Resize size of collection view items in grid so that we achieve 3 boxes across
loadCollectionViewData()
}
/*
==========================================================================================
Ensure data within the collection view is updated when ever it is displayed
==========================================================================================
*/
// Load data into the collectionView when the view appears
override func viewDidAppear(animated: Bool) {
loadCollectionViewData()
}
/*
==========================================================================================
Fetch data from the Parse platform
==========================================================================================
*/
func loadCollectionViewData() {
// Build a parse query object
}
/*
==========================================================================================
UICollectionView protocol required methods
==========================================================================================
*/
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return self.votes.count
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("newview", forIndexPath: indexPath) as! NewCollectionViewCell
let item = self.votes[indexPath.row]
// Display "initial" flag image
var initialThumbnail = UIImage(named: "question")
cell.postsImageView.image = initialThumbnail
if let pointer = item["uploader"] as? PFObject {
cell.userName!.text = item["username"] as? String
print("username")
}
if let profile = item["uploader"] as? PFObject,
profileImageFile = profile["profilePicture"] as? PFFile {
cell.profileImageView.file = profileImageFile
cell.profileImageView.loadInBackground { image, error in
if error == nil {
cell.profileImageView.image = image
}
}
}
if let votesValue = item["votes"] as? Int
{
cell.votesLabel?.text = "\(votesValue)"
}
// Fetch final flag image - if it exists
if let value = item["imageFile"] as? PFFile {
println("Value \(value)")
cell.postsImageView.file = value
cell.postsImageView.loadInBackground({ (image: UIImage?, error: NSError?) -> Void in
if error != nil {
cell.postsImageView.image = image
}
})
}
return cell
}
In my post class it is like this
The users are managed in the user class. I want to get the profile image and username of the person who posted the image.
In the user class I have all the user information.

Answer 1

cell.postsImageView.loadInBackground({
(image: UIImage!, error: NSError!) -> Void in
if error == nil {
if image != nil {
dispatch_async(dispatch_get_main_queue(),{
cell.postsImageView.image = image
})
}else{
println("Image not available")
}
}else{
println(Image Downloading error: \(error))
}
})
Try this , i think this will help you :)

Answer 2

Try to replace your loadInBackground method with the below:
cell.postsImageView.loadInBackground({ (image: UIImage!, error: NSError!) -> Void in
if error == nil {
cell.postsImageView.file = value
cell.postsImageView.image = image
}
})
}

Answer 3

You have two issues here, the first being the way you pass the closure to the loadInBackground method
The compiler error is because you're trying to call the method with non-optional closure parameters.
In the cell.postsImageView.loadInBackground call you use optionals, while in the cell.profileImageView.loadInBackground you don't.
Closure parameter types are important, that's why the compiler is complaining.
I'd suggest skipping the types and defining the closure like this:
cell.profileImageView.loadInBackground { image, error in
if error != nil{
cell.profileImageView.image = image
}
})}
The other and probably your main issue is that you don't set a file for the profile. So, if we say that the profile image is stored under imageFile in the uploader object, you would use:
if let profile = item["uploader"] as? PFObject,
profileImageFile = profile["imageFile"] as? PFFile {
cell.profileImageView.file = profileImageFile
cell.profileImageView.loadInBackground { image, error in
if error == nil {
cell.profileImageView.image = image
}
}
}
Though, as the Parse documentation says, the method downloads and displays the image:
Once the download completes, the remote image will be displayed.
https://parse.com/docs/ios/api/Classes/PFImageView.html#//api/name/loadInBackground:
If you don't need any special error handling and since you already have a placeholder image, try loading the image like this:
if let profile = item["uploader"] as? PFObject,
profileImageFile = profile["imageFile"] as? PFFile {
cell.profileImageView.file = profileImageFile
cell.profileImageView.loadInBackground()
}