Obtaining image details in detailviewcontroller when clicking image in collectionviewcontroller - ios

Question

My CollectionViewController contains an image. When I click the image in my CollectionViewController it takes me to the detailviewcontroller where I want to edit the details of the image. When I enter the details such as an URL, then click the back button, it should fetch the image from the URL and replace the image in my CollectionViewController.
I have two problems:
When I click the image in my CollectionViewController it opens the detailviewcontroller, but it doesn't show the url of the image I clicked.
When I click the back button it does not take me back to the CollectionViewController.
import Foundation
class Photo {
var url: String = ""
var data: NSData? = nil
var Title: String = ""
var Tags: String = ""
func loadImage(completionHandler: (data: NSData?) ->Void) {
let queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0)
dispatch_async(queue) {
let mainQueue = dispatch_get_main_queue()
if let url = NSURL(string: self.url) {
if let data = NSData(contentsOfURL: url) {
sleep(3)
dispatch_async(mainQueue) {
self.data = data
completionHandler(data: data)
}
return
}
dispatch_async(mainQueue) {
completionHandler(data: nil)
}
}
}
}
}
detailviewcontroller
import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
var photo: Photo!
#IBOutlet weak var textURL: UITextField!
#IBOutlet weak var textTitle: UITextField!
#IBOutlet weak var textTags: UITextField!
#IBOutlet weak var imageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
let urlString = textField.text
photo.url = urlString
let DatatoImage: (NSData?) -> Void = {
if let d = $0 {
let image = UIImage(data: d)
self.imageView.image = image
} else {
self.imageView.image = nil
}
//textField.resignFirstResponder()
}
if let d = photo.data {
DatatoImage(d)
textField.resignFirstResponder()
let image = UIImage(data: d)
self.imageView.image = image
} else {
photo.loadImage(DatatoImage)
}
return true
}
}
My masterViewController
import UIKit
let reuseIdentifier = "Cell"
class PhotosCollectionViewController: UICollectionViewController {
var photos = Array<Photo>()
override func viewDidLoad() {
super.viewDidLoad()
let photo = Photo()
photo.url = "http://www.griffith.edu.au/__data/assets/image/0019/632332/gu-header-logo.png"
photos.append(photo)
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Register cell classes
self.collectionView!.registerClass(PhotoCollectionViewCell.self, forCellWithReuseIdentifier: reuseIdentifier)
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
//#warning Incomplete method implementation -- Return the number of sections
return 1
}
override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return photos.count
}
override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as PhotoCollectionViewCell
let photo = photos[indexPath.row]
if let d = photo.data {
let image = UIImage(data: d)
cell.imageView.image = image
photo.url = "\(photo.url)"
photo.Title = "\(photo.Title)"
} else {
photo.loadImage {
if $0 != nil {
collectionView.reloadItemsAtIndexPaths([indexPath])
}
}
}
return cell
}
// Uncomment this method to specify if the specified item should be highlighted during tracking
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if let indexPath = sender as? NSIndexPath {
let photo = photos[indexPath.row]
}
if (segue.identifier == "showDetail") {
if let dvc = segue.destinationViewController as? ViewController {
let photo = Photo()
dvc.photo = photo
}
}
}
override func collectionView(collectionView: UICollectionView, shouldHighlightItemAtIndexPath indexPath: NSIndexPath) -> Bool {
performSegueWithIdentifier("showDetail", sender: indexPath)
return true
}

Answer 1

In your prepareForSegue method, you have this line,
let photo = Photo()
This creates a new Photo object, it doesn't get the one you were displaying in the cell you selected. You got a reference to the correct one in your if let statement. Use that one (let photo = photos[indexPath.row]).
As for the back button, you shouldn't have to write any code to make that work, if that back button is the one you get automatically when you push to a new controller.