How would I make a like button? - swift

Question

I am working on making a social media app clone using tutorials for practice in Swift, but I want to add a like button with Parse but not sure how. Does anyone know a tutorial or do you know how you would go about doing this? I attempted to make one like this but I'm pretty sure it is not correct...
I put this in the cell view controller
#IBAction func likeButton(sender: AnyObject) {
a++
var post = PFObject(className: "Post")
post["likes"] = a
}
}
This went into the feed view controller...
var messages = [String]()
var usernames = [String]()
var imageFiles = [PFFile]()
var users = [String: String]()
var likesArray = [String]()
override func viewDidLoad() {
super.viewDidLoad()
var query = PFUser.query()
query?.findObjectsInBackgroundWithBlock({ (objects, error) -> Void in
if let users = objects {
self.messages.removeAll(keepCapacity: true)
self.users.removeAll(keepCapacity: true)
self.imageFiles.removeAll(keepCapacity: true)
self.usernames.removeAll(keepCapacity: true)
self.likesArray.removeAll(keepCapacity: true)
for object in users {
if let user = object as? PFUser {
self.users[user.objectId!] = user.username!
}
}
}
})
var getFollowedUsersQuery = PFQuery(className: "followers")
getFollowedUsersQuery.whereKey("follower", equalTo: PFUser.currentUser()!.objectId!)
getFollowedUsersQuery.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if let objects = objects {
for object in objects {
var followedUser = object["following"] as! String
var query = PFQuery(className: "Post")
query.whereKey("userId", equalTo: followedUser)
query.findObjectsInBackgroundWithBlock({ (objects, error) -> Void in
if let objects = objects {
for object in objects {
self.messages.append(object["message"] as! String)
self.imageFiles.append(object["imageFile"] as! PFFile)
self.usernames.append(self.users[object["userId"] as! String]!)
self.likesArray.append(object["likes"] as? String)
self.tableView.reloadData()
}
}
})
}
}
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Potentially incomplete method implementation.
// Return the number of sections.
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete method implementation.
// Return the number of rows in the section.
return usernames.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let myCell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! cell
imageFiles[indexPath.row].getDataInBackgroundWithBlock { (data, error) -> Void in
if let downloadedImage = UIImage(data: data!) {
myCell.postedImage.image = downloadedImage
}
}
myCell.username.text = usernames[indexPath.row]
myCell.message.text = messages[indexPath.row]
myCell.likeLabel.text = likesArray[indexPath.row]
myCell.selectionStyle = .None
return myCell
}
}
This is the view controller when you post the picture and message...
var likes = 0
var picSelected = false
#IBOutlet var feed: UIButton!
func displayAlert(title: String, message: String) {
var alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: { (action) -> Void in
}))
presentViewController(alert, animated: true, completion: nil)
}
var activityIndicator = UIActivityIndicatorView()
#IBOutlet var imageToPost: UIImageView!
#IBAction func chooseImage(sender: AnyObject) {
var image = UIImagePickerController()
image.delegate = self
image.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
image.allowsEditing = false
presentViewController(image, animated: true, completion: nil)
}
func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage!, editingInfo: [NSObject : AnyObject]!) {
dismissViewControllerAnimated(true, completion: nil)
imageToPost.image = image
picSelected = true
}
#IBOutlet var message: UITextField!
#IBAction func postImage(sender: AnyObject) {
if message.text != "" && picSelected != false {
picSelected = false
activityIndicator = UIActivityIndicatorView(frame: view.frame)
activityIndicator.backgroundColor = UIColor(white: 1.0, alpha: 0.5)
activityIndicator.center = self.view.center
activityIndicator.hidesWhenStopped = true
activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray
view.addSubview(activityIndicator)
activityIndicator.startAnimating()
UIApplication.sharedApplication().beginIgnoringInteractionEvents()
var post = PFObject(className: "Post")
post["message"] = message.text
post["userId"] = PFUser.currentUser()?.objectId!
let imageData = UIImagePNGRepresentation(imageToPost.image)
let imageFile = PFFile(name: "image.png", data: imageData)
post["imageFile"] = imageFile
post["likes"] = a
post.saveInBackgroundWithBlock { (success, error) -> Void in
self.activityIndicator.stopAnimating()
UIApplication.sharedApplication().endIgnoringInteractionEvents()
if error == nil {
self.displayAlert("Image Posted!", message: "Your image has been posted successfully.")
self.imageToPost.image = UIImage(named: "Blank-Person1.png")
self.message.text = ""
}
}
} else {
displayAlert("Could Not Post Image!", message: "Please enter a message and/or select a picture.")
}
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
}

Answer 1

I'm about to make Like button like this:
Create Names column in parse ( Array column) to hold names who click on like button
Create Likes column in parse (integer column) to hold count number of Names column
and when someone click on like button add his name to Names Array in parse, If he click it again remove his name
And you need to take all names in NamesArray column and count them in swift then update likes column
i'm not sure but that's in my mind right now, but if you think of it you'll get better way.