Swift: How to use "prepareForSegue" inside UICollectionViewCell? - ios

Question

I have a UICollectionView inside a UITableView, I want to link another ViewController when the UICollectionViewCell is tapped by user. Inside the UITableViewCell, I downloaded all the data from the Internet and stored in an array. I created a Segue by control drag the CollectionViewCell to the new ViewController and chose "Push". Inside the new ViewController, I added an IBOutlet of UIImageView to show the image of the CollectionViewCell when user tapped the thumbnail. Now when I tapped the CollectionViewCell, it goes to the new ViewController, but there is no pics showed. here is my code, any suggestions?
In the UITableViewConroller:
import UIKit
class HomePageTableViewController: UITableViewController {
let sections: NSArray = ["latest news", "good news"]
var posts1: [Posts] = [Posts]()
override func viewDidLoad() {
super.viewDidLoad()
}
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if section < sections.count{
return sections[section] as? String
}
return nil
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return sections.count
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if indexPath.row == 0 && indexPath.section == 0 {
let tableViewCell = tableView.dequeueReusableCellWithIdentifier("TableViewCell") as! TableViewCell
tableViewCell.getCategories()
// tableViewCell.scrollToNextCell()
// tableViewCell.startTimer()
return tableViewCell
}
and inside TableViewCell, here is the code:
import UIKit
import Alamofire
import AlamofireImage
class TableViewCell: UITableViewCell, UICollectionViewDataSource,
UICollectionViewDelegate {
var posts1: [Posts] = [Posts]()
var posts2: [Posts] = [Posts]()
var categories: [Category] = [Category]()
var selectedPost1: Posts?
#IBOutlet weak var theCollectionView: UICollectionView!
I download all the data from JSON and put them inside these arrays. inside this class, I also tried to call the function :
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
print("selected")
self.selectedPost1 = self.posts1
}
the print works when I tapped a cell, but I can't use "prepareForSegue" inside this function. I checked and found out that this function can only be used in ViewController, but how can I do that?
And inside the new ViewController, here is the code:
import UIKit
class DetailViewController: UIViewController {
#IBOutlet weak var postImageView: UIImageView!
var posts: [Posts] = [Posts]()
var selectedPost: Posts?
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(animated: Bool) {
if let post = self.selectedPost{
let thumbnailUrlString = post.postThumbnailUrlString
let imageUrl: NSURL = NSURL(string: thumbnailUrlString)!
print(thumbnailUrlString)
postImageView.af_setImageWithURL(imageUrl)
}
}
}
Since when I download the data, I put them into 2 different array, posts1 and posts2. I want to show the corresponding images in the new ViewController. But I just created one "selectedPost" array, I am not sure is that the problem? and I am not sure if I reload the data to the "selectedPost" array, maybe thats why there is no images showing? really hope anyone can give me some suggestions. thanks

Answer 1

You should use prepareForSegue:. What you need to do is have a var selectedIndexPath which is set whenever you select a cell. Then in prepareForSegue: you can access the cell and it's properties i.e:
HomePageTableViewController: UITableViewController {
var selectedIndexPath: NSIndexPath?
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
selectedIndexPath = indexPath
}
public override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
super.prepareForSegue(segue, sender: sender)
let cell = theCollectionView.cellForItemAtIndexPath(selectedIndexPath)
//do what you need to do
}
}