Я пытаюсь сделать кнопку «Мне нравится», и в отличие от нее, но она выдает ошибку, когда я пытаюсь нажать кнопку в симуляторе. Если вы знаете, какой-либо другой код для кнопки «Мне нравится» будет намного проще (или некоторые веб-сайты, yt vids)
@IBOutlet weak var postTextLabel: UILabel!
@IBOutlet weak var subtitleLabel: UILabel!
@IBOutlet weak var profileImageView: UIImageView!
@IBOutlet weak var usernameLabel: UILabel!
@IBOutlet weak var likeLabel : UILabel!
@IBOutlet weak var likeBtn: UIButton!
@IBOutlet weak var unlikeBtn: UIButton!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
profileImageView.layer.cornerRadius = profileImageView.bounds.height / 2
profileImageView.clipsToBounds = true
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
weak var post:Post?
func set(post:Post) {
self.post = post
var postID : String!
self.profileImageView.image = nil
ImageService.getImage(withURL: post.author.photoURL) { image , url in
guard let _post = self.post else {return}
if _post.author.photoURL.absoluteString == url.absoluteString {
self.profileImageView.image = image
}else {
print("not the right image")
}
}
usernameLabel.text = post.author.username
postTextLabel.text = post.text
subtitleLabel.text = post.createdAt.calenderTimeSinceNow()
}
var postID : String!
@IBAction func likePressed(_ sender: Any) {
self.postID = "post_0"
let ref = Database.database().reference()
let keyToPost = ref.child("posts").childByAutoId().key
ref.child("posts").child(self.postID).observeSingleEvent(of: .value) { (snapshot) in
if let post = snapshot.value as? [String : AnyObject] {
let updateLikes : [ String : Any] = [ "peopleWhoLike/\(keyToPost)" : Auth.auth().currentUser!.uid ]
ref.child("posts").child(self.postID).updateChildValues(updateLikes, withCompletionBlock : {(error ,reff) in
if error == nil {
ref.child("posts").child(self.postID).observeSingleEvent(of : .value, with: { (snap) in
if let properties = snap.value as? [ String : AnyObject] {
if let likes = properties["peopleWhoLike"] as? [String: AnyObject] {
let count = likes.count
self.likeLabel.text = "\(count) Likes"
}
}
})
}
})
}
}
}
@IBAction func unlikedPressed(_ sender:Any) {
let ref = Database.database().reference()
ref.child("posts").child(self.postID).observeSingleEvent(of: .value, with: { (snapshot) in
if let properties = snapshot.value as? [String : AnyObject] {
if let peopleWhoLike = properties["peopleWhoLike"] as? [String: AnyObject] {
for (id,person) in peopleWhoLike {
if person as? String == Auth.auth().currentUser!.uid {
ref.child("posts").child(self.postID).child("peopleWhoLike").child(id).removeValue(completionBlock: {(error , reff)in
if error == nil {
ref.child("posts").child(self.postID).observeSingleEvent(of: .value, with: {(snap) in
if let prop = snap.value as? [String : AnyObject] {
if let likes = prop["peopleWhoLike"] as? [String: AnyObject] {
let count = likes.count
self.likeLabel.text = "\(count) Likes"
ref.child("posts").child(self.postID).updateChildValues(["likes" : count])
} else {
self.likeLabel.text = " 0 Likes"
ref.child("posts").child(self.postID).updateChildValues(["likes" : 0])
}
}
})
}
})
self.likeBtn.isHidden = false
self.unlikeBtn.isHidden = true
self.unlikeBtn.isEnabled = true
break
}
}
}
}
})
ref.removeAllObservers()
}
}
class HomeController: UIViewController, UITableViewDelegate, UITableViewDataSource {
func numberOfSections(in tableView: UITableView) -> Int {
return 2
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
switch section {
case 0:
return posts.count
case 1:
return fetchingMore ? 1 : 0
default:
return 0
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.section == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: "postCell", for: indexPath) as! PostTableViewCell
cell.set(post: posts[indexPath.row])
return cell
} else {
let cell = tableView.dequeueReusableCell(withIdentifier: "loadingCell", for: indexPath) as! LoadingCell
cell.spinner.startAnimating()
return cell
}
}
var tableView:UITableView!
var cellHeights: [IndexPath : CGFloat] = [:]
var posts = [Post]()
var fetchingMore = false
var endReached = false
let leadingScreensForBatching:CGFloat = 3.0
var refreshControl:UIRefreshControl!
var seeNewPostsButton:SeeNewPostsButton!
var seeNewPostsButtonTopAnchor:NSLayoutConstraint!
var lastUploadedPostID:String?
var postsRef:DatabaseReference {
return Database.database().reference().child("posts")
}
var oldPostsQuery:DatabaseQuery {
var queryRef:DatabaseQuery
let lastPost = posts.last
if lastPost != nil {
let lastTimestamp = lastPost!.createdAt.timeIntervalSince1970 * 1000
queryRef = postsRef.queryOrdered(byChild: "timestamp").queryEnding(atValue: lastTimestamp)
} else {
queryRef = postsRef.queryOrdered(byChild: "timestamp")
}
return queryRef
}
var newPostsQuery:DatabaseQuery {
var queryRef:DatabaseQuery
let firstPost = posts.first
if firstPost != nil {
let firstTimestamp = firstPost!.createdAt.timeIntervalSince1970 * 1000
queryRef = postsRef.queryOrdered(byChild: "timestamp").queryStarting(atValue: firstTimestamp)
} else {
queryRef = postsRef.queryOrdered(byChild: "timestamp")
}
return queryRef
}
@IBAction func handleLogoutButton(_ sender: Any) {
try! Auth.auth().signOut()
}
override func viewDidLoad() {
super.viewDidLoad()
tableView = UITableView(frame: view.bounds, style: .plain)
let cellNib = UINib(nibName: "PostTableViewCell", bundle: nil)
tableView.register(cellNib, forCellReuseIdentifier: "postCell")
tableView.register(LoadingCell.self, forCellReuseIdentifier: "loadingCell")
tableView.backgroundColor = UIColor(white: 0.90,alpha:1.0)
view.addSubview(tableView)
var layoutGuide:UILayoutGuide!
if #available(iOS 11.0, *) {
layoutGuide = view.safeAreaLayoutGuide
} else {
// Fallback on earlier versions
layoutGuide = view.layoutMarginsGuide
}
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor).isActive = true
tableView.topAnchor.constraint(equalTo: layoutGuide.topAnchor).isActive = true
tableView.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: layoutGuide.bottomAnchor).isActive = true
tableView.delegate = self
tableView.dataSource = self
tableView.reloadData()
refreshControl = UIRefreshControl()
if #available(iOS 10.0, *) {
tableView.refreshControl = refreshControl
} else {
// Fallback on earlier versions
tableView.addSubview(refreshControl)
}
refreshControl.addTarget(self, action: #selector(handleRefresh), for: .valueChanged)
seeNewPostsButton = SeeNewPostsButton()
view.addSubview(seeNewPostsButton)
seeNewPostsButton.translatesAutoresizingMaskIntoConstraints = false
seeNewPostsButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
seeNewPostsButtonTopAnchor = seeNewPostsButton.topAnchor.constraint(equalTo: layoutGuide.topAnchor, constant: -44)
seeNewPostsButtonTopAnchor.isActive = true
seeNewPostsButton.heightAnchor.constraint(equalToConstant: 32.0).isActive = true
seeNewPostsButton.widthAnchor.constraint(equalToConstant: seeNewPostsButton.button.bounds.width).isActive = true
seeNewPostsButton.button.addTarget(self, action: #selector(handleRefresh), for: .touchUpInside)
//observePosts()
beginBatchFetch()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
listenForNewPosts()
}
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(animated)
stopListeningForNewPosts()
}
func toggleSeeNewPostsButton(hidden:Bool) {
if hidden {
// hide it
UIView.animate(withDuration: 0.5, delay: 0.0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseOut, animations: {
self.seeNewPostsButtonTopAnchor.constant = -44.0
self.view.layoutIfNeeded()
}, completion: nil)
} else {
// show it
UIView.animate(withDuration: 0.5, delay: 0.0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseOut, animations: {
self.seeNewPostsButtonTopAnchor.constant = 12
self.view.layoutIfNeeded()
}, completion: nil)
}
}
@objc func handleRefresh() {
print("Refresh!")
toggleSeeNewPostsButton(hidden: true)
newPostsQuery.queryLimited(toFirst: 20).observeSingleEvent(of: .value, with: { snapshot in
var tempPosts = [Post]()
let firstPost = self.posts.first
for child in snapshot.children {
if let childSnapshot = child as? DataSnapshot,
let data = childSnapshot.value as? [String:Any],
let post = Post.parse(childSnapshot.key, data),
childSnapshot.key != firstPost?.id {
tempPosts.insert(post, at: 0)
}
}
self.posts.insert(contentsOf: tempPosts, at: 0)
let newIndexPaths = (0..<tempPosts.count).map { i in
return IndexPath(row: i, section: 0)
}
self.refreshControl.endRefreshing()
self.tableView.insertRows(at: newIndexPaths, with: .top)
self.tableView.scrollToRow(at: IndexPath(row: 0, section: 0), at: .top, animated: true)
self.listenForNewPosts()
})
}
func fetchPosts(completion:@escaping (_ posts:[Post])->()) {
oldPostsQuery.queryLimited(toLast: 20).observeSingleEvent(of: .value, with: { snapshot in
var tempPosts = [Post]()
let lastPost = self.posts.last
for child in snapshot.children {
if let childSnapshot = child as? DataSnapshot,
let data = childSnapshot.value as? [String:Any],
let post = Post.parse(childSnapshot.key, data),
childSnapshot.key != lastPost?.id {
tempPosts.insert(post, at: 0)
}
}
return completion(tempPosts)
})
}
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let offsetY = scrollView.contentOffset.y
let contentHeight = scrollView.contentSize.height
if offsetY > contentHeight - scrollView.frame.size.height * leadingScreensForBatching {
if !fetchingMore && !endReached {
beginBatchFetch()
}
}
}
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
cellHeights[indexPath] = cell.frame.size.height
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return cellHeights[indexPath] ?? 72.0
}
func beginBatchFetch() {
fetchingMore = true
self.tableView.reloadSections(IndexSet(integer: 1), with: .fade)
fetchPosts { newPosts in
self.posts.append(contentsOf: newPosts)
self.fetchingMore = false
self.endReached = newPosts.count == 0
UIView.performWithoutAnimation {
self.tableView.reloadData()
self.listenForNewPosts()
}
}
}
var postListenerHandle:UInt?
func listenForNewPosts() {
guard !fetchingMore else { return }
// Avoiding duplicate listeners
stopListeningForNewPosts()
postListenerHandle = newPostsQuery.observe(.childAdded, with: { snapshot in
if snapshot.key != self.posts.first?.id,
let data = snapshot.value as? [String:Any],
let post = Post.parse(snapshot.key, data) {
self.stopListeningForNewPosts()
if snapshot.key == self.lastUploadedPostID {
self.handleRefresh()
self.lastUploadedPostID = nil
} else {
self.toggleSeeNewPostsButton(hidden: false)
}
}
})
}
func stopListeningForNewPosts() {
if let handle = postListenerHandle {
newPostsQuery.removeObserver(withHandle: handle)
postListenerHandle = nil
}
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let newPostNavBar = segue.destination as? UINavigationController,
let newPostVC = newPostNavBar.viewControllers[0] as? NewPostViewController {
newPostVC.delegate = self
}
}
}
расширение HomeController: NewPostVCDelegate {
func didUploadPost(withID id: String) {
self.lastUploadedPostID = id
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destination.
// Pass the selected object to the new view controller.
}
*/
}
Я пытаюсь сделать кнопку «Мне нравится» и в отличие от нее, но она выдает ошибку, когда я пытаюсь нажать кнопку в симуляторе. Если вы знаете, что любой другой код для кнопки «Мне нравится» будет намного проще (будет полезно на некоторых сайтах,Vids)