Swift 3: Segue and pass in data from one class to another - swift

Question

I have a simple UICollectionViewController called HomeController that has a bunch of cells. These cells have a class of their own called PostCell. I also have a NSObject class that holds all the data for every Post (these posts are my cells). Inside my PostCell I have a UIView called profileSegueContainer. When I tap this UIView, I want to segue to a new controller. I am able to achieve this with a presentViewController method but I also want to pass in the info of that specific post. For example, if I tap a cell that has the uid of "1234", I want to be able to not only segue to the new controller but also pass this uid into it. Of course if I tap the next cell and the post.uid of that cell is "4567", then I want to also pass that in when I segue. I hope this makes sense... I want it to work similar to Instagrams "tapped on a user to get to their profile" feature. I hope this makes sense. Any help will be highly appreciated and of course, I will mark as answer. Thank you. All the relevant code is below:
class Post: NSObject {
var author: String?
var avatar_image_url: String?
var likes: Int?
var postImageUrl: String?
var uid: String?
var post_id: String?
var hashtags: [String]?
}
class HomeController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
var postCell: PostCell?
var userProfileController: UserProfileController?
var posts = [Post]()
var timer: Timer?
override func viewDidLoad() {
super.viewDidLoad()
self.collectionView?.backgroundColor = grayBackgroundColor
self.collectionView?.register(PostCell.self, forCellWithReuseIdentifier: reuseIdentifier)
self.collectionView?.contentInset = UIEdgeInsetsMake(16, 0, 16, 0)
self.collectionView?.alwaysBounceVertical = true
self.collectionView?.showsVerticalScrollIndicator = false
setupNavigationBarBranding()
checkIfUserIsLoggedIn()
fetchPosts()
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let frameWidth = self.view.frame.size.width
let width = frameWidth - (16 + 16)
let height = frameWidth - (16 / 9) + 50 + 50
return CGSize(width: width, height: height)
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return posts.count
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! PostCell
cell.homeController = self
cell.post = posts[indexPath.item]
userProfileController?.post = posts[indexPath.item]
return cell
}
}
class PostCell: BaseCell {
var homeController: HomeController?
var userProfileController: UserProfileController?
var post: Post? {
didSet {
if let postDisplayName = post?.author {
displayName.text = postDisplayName
}
if let postImageUrl = post?.postImageUrl {
postImage.loadImageUsingCacheWithUrlString(urlString: postImageUrl)
}
if let postProfileImage = post?.avatar_image_url {
profileImage.loadImageUsingCacheWithUrlString(urlString: postProfileImage)
}
}
}
lazy var profileSegueContainer: UIView = {
let view = UIView()
view.isUserInteractionEnabled = true
return view
}()
func handleProfileSegue() {
let userProfile = UserProfileController()
let navigationUserProfile = UINavigationController(rootViewController: userProfile)
homeController?.present(navigationUserProfile, animated: true, completion: nil)
}
override func setupViews() {
super.setupViews()
let tap = UITapGestureRecognizer(target: self, action: #selector(handleProfileSegue))
profileSegueContainer.addGestureRecognizer(tap)
addSubview(profileSegueContainer)
_ = profileSegueContainer.anchor(profileImage.topAnchor, left: profileImage.leftAnchor, bottom: profileImage.bottomAnchor, right: displayName.rightAnchor, topConstant: 0, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)
}

Answer 1

Segue has a very specific meaning, in the context of View Controllers. You probably want to use the phrase "push another view controller" instead.
First off, UINavigationController is typically only used once in a scene -- it's the view controller that keeps track of a stack of sub-View Controllers. You only create one of them, and you probably want to set your HomeController as the nav controller's rootViewController.
Then when the user taps the view you should forward this to a method you will add to HomeController; this will create your custom UserProfile class, configure it with the data it needs, and then call: navigationController?.pushViewController(userProfile, animating: true)
There are many fine tutorials around that show you how this all works.