Fetching data from Parse.com into custom cell (swift) - ios

Question

I am attempting to fetch data from parse.com into my custom cell which is full of strings and images. I believe I am either retrieving my PFFile incorrectly from parse.com or I am retrieving the PFFile correctly but converting the file to UIImage improperly. The error i am receiving is going on within the loadData() function. It reads as follows: could not find an overload for 'init' that accepts the supplied arguments
Information
//Used to set custom cell
class Information {
var partyName = ""
var promoterName = ""
var partyCost = ""
var flyerImage: UIImage
var promoterImage: UIImage
init(partyName: String, promoterName: String, partyCost: String, flyerImage: UIImage, promoterImage: UIImage) {
self.partyName = partyName
self.promoterName = promoterName
self.partyCost = partyCost
self.flyerImage = flyerImage
self.promoterImage = promoterImage
}
}
Parse fetch function
func loadData() {
var findDataParse:PFQuery = PFQuery(className: "flyerDataFetch")
findDataParse.findObjectsInBackgroundWithBlock{
(objects: [AnyObject]?, error: NSError?) -> Void in
if (error == nil) {
for object in objects! {
var eventImage0 : UIImage
var eventImage10 : UIImage
let userImageFile = object["partyFlyerImage"] as! PFFile
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
let eventImage = UIImage(data:imageData!)
eventImage0 = eventImage!
}
}
let userImageFile1 = object["partyPromoterImage"] as! PFFile
userImageFile1.getDataInBackgroundWithBlock {
(imageData1: NSData?, error1: NSError?) -> Void in
if error1 == nil {
let eventImage1 = UIImage(data:imageData1!)
eventImage10 = eventImage1!
}
}
//Error below
var party1 = Information(partyName: (object["partyName"] as? String)!, promoterName: (object["partyPromoterName"] as? String)!,partyCost: (object["partyCost"] as? String)!, flyerImage: UIImage(data: eventImage0)!, promoterImage: UIImage(data: eventImage10)!)
self.arrayOfParties.append(party1)
}
}
self.tableView.reloadData()
}
}

Answer 1

You are fetching data from Parse in background, but processing on main thread. Try this:
func loadData() {
var findDataParse:PFQuery = PFQuery(className: "flyerDataFetch")
findDataParse.findObjectsInBackgroundWithBlock{
(objects: [AnyObject]?, error: NSError?) -> Void in
if (error == nil) {
for object in objects! {
var eventImage0 : UIImage
var eventImage10 : UIImage
let userImageFile = object["partyFlyerImage"] as! PFFile
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
let eventImage = UIImage(data:imageData!)
eventImage0 = eventImage!
let userImageFile1 = object["partyPromoterImage"] as! PFFile
userImageFile1.getDataInBackgroundWithBlock {
(imageData1: NSData?, error1: NSError?) -> Void in
if error1 == nil {
let eventImage1 = UIImage(data:imageData1!)
eventImage10 = eventImage1!
var party1 = Information(partyName: (object["partyName"] as? String)!, promoterName: (object["partyPromoterName"] as? String)!, partyCost: (object["partyCost"] as? String)!, flyerImage: UIImage(data: eventImage0)!, promoterImage: UIImage(data: eventImage10)!)
self.arrayOfParties.append(party1)
}
}
}
}
}
}
self.tableView.reloadData()
}
}

Answer 2

Your fetching your images Asynchronously and creating your Information cell Synchronously. So when you create the cell, the images are likely not loaded and your are in effect sending nil to the constructor for the cell.
In the following code you are retrieving the image data async:
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
let eventImage = UIImage(data:imageData!)
eventImage0 = eventImage!
}
}
So when you assign the image data to eventImage0, the call to the Information cell initializer has probably already happened.
You need to modify the code to instead of passing the image into the cell view initializer, allow you to access the UIImageview from the Information cell, so that when the background image loads complete you can simply set the loaded image into that UI/PF/ImageView.