Like button doesn't work every time - ios

Question

I'm trying to make a social media app and one of the features is the like button, unfortunately when you click everything works fine but all of the time it doesn't update the amount of likes correctly and the like button correctly. I believe it's something to do with the refreshing it but I need it to be refreshed so that it can update the amount of likes. Does anyone know what's going on...
func like(sender: AnyObject) {
var buttonPosition: CGPoint = sender.convertPoint(CGPointZero, toView: self.table)
var indexPath: NSIndexPath = self.table.indexPathForRowAtPoint(buttonPosition)!
if sender.currentTitle == "Like" {
sender.setTitle("Unlike", forState: .Normal)
var addLikeQuery = PFQuery(className: "Post")
addLikeQuery.whereKey("message", equalTo: self.messages[indexPath.row])
addLikeQuery.findObjectsInBackgroundWithBlock { (aPosts, error) -> Void in
if let aPosts = aPosts {
for aPost in aPosts {
aPost.addUniqueObject(PFUser.currentUser()!.objectId!, forKey: "likers")
self.likeDisplayText = ((aPost["likers"] as! [String]).count - 1).description + " Like"
self.table.reloadRowsAtIndexPaths([indexPath], withRowAnimation: .None)
aPost.saveInBackgroundWithBlock({ (success, error) -> Void in
if error != nil {
self.likeDisplayText = "Couldn't Like Picture!"
}
})
}
}
}
} else {
sender.setTitle("Like", forState: .Normal)
var removeLikeQuery = PFQuery(className: "Post")
removeLikeQuery.whereKey("message", equalTo: self.messages[indexPath.row])
removeLikeQuery.findObjectsInBackgroundWithBlock { (rPosts, error) -> Void in
if let rPosts = rPosts {
for rPost in rPosts {
rPost.removeObject(PFUser.currentUser()!.objectId!, forKey: "likers")
self.likeDisplayText = ((rPost["likers"] as! [String]).count - 1).description + " Like"
self.table.reloadRowsAtIndexPaths([indexPath], withRowAnimation: .None)
rPost.saveInBackgroundWithBlock({ (success, error) -> Void in
if error != nil {
self.likeDisplayText = "Couldn't Like Picture!"
}
})
}
}
}
}
}

Answer 1

I'm not exactly sure what your question is but i may have some insight. If you are trying to edit some elemts in your UI through a function that does a lot of processing or is in another thread i suggest making it Asynchronus and anywhere in that function where you are editing UI make that code run on the main thread. Here's what i mean.
func like(sender: AnyObject) {
dispatch_async(dispatch_get_global_queue(Int(QOS_CLASS_USER_INITIATED.value), 0)) {
// do background stuff
dispatch_async(dispatch_get_main_queue()) {
// when you want to edit the text of the button
// or change something in your UI
// do it in here
self.likeDisplayText = "Couldn't Like Picture!"
}
}
}