Vote feature implementation - ios

Hello I get an error saying Could not find overload for != that accepts the supplied documents and don't know what to change. I am stuck for a very long time. I am trying to implement a vote feature in a collection view. If the user taps the button it adds one vote to parse and shows it on the label. Is my method wrong? Below is the code for Collection view cell the highlighted code is where the error is.
import UIKit
import ParseUI
import Parse
var votes = [PFObject]()
class NewCollectionViewCell: UICollectionViewCell {
var parseObject = PFObject(className: "Posts")
#IBOutlet weak var postsImageView: PFImageView!
#IBOutlet weak var postsLabel: UILabel!
#IBOutlet weak var votesLabel:UILabel?
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
postsLabel.textAlignment = NSTextAlignment.Center
print("Passing11")
}
#IBAction func vote(sender: AnyObject) {
if (parseObject != nil)
{
if let votes = parseObject!.objectForKey("votes") as? Int {
parseObject!.setObject(votes + 1, forKey: "votes")
parseObject!.saveInBackgroundWithTarget(nil, selector: nil)
votesLabel?.text = "\(votes + 1) votes"
print("Passing22")
}
else
{
parseObject!.setObject(1, forKey: "votes")
parseObject!.saveInBackgroundWithTarget(nil, selector: nil)
votesLabel?.text = "1 votes"
print("Passing33")
}
}}}
And I also have an error "use of unresolved identifier parse objects"
if (parseObject != nil)
{
if let votes = parseObject!.objectForKey("votes") as? Int {
cell.votesLabel?.text = "\(votes) votes"
}
else
{
cell.votesLabel?.text = "0 votes"
}
}
return cell}
Any help is appreciated. Thank you.

This compiler error will appear only if your parseObject is of type PFObject and not PFObject?.
From what I can see through your code:
var parseObject = PFObject(className: "Posts")
The above line states that your parseObject will be of type PFObject and not optional. It will be optional only if your initializer is failable.
So if parseObject is not optional, then there is no need for nil check.
Hope it helps.

Related

iOS Swift & Parse - getDataInBackground not working?

Currently learning Swift & iOS. I try to access with Parse a saved picture. However, I can't access it with getDataInBackground(block:).
Here's my code:
//
// ViewController.swift
// Instragram
//
// Created by Macbook Pro on 22.07.17.
// Copyright © 2017 Macbook Pro. All rights reserved.
//
import UIKit
import Parse
class ViewController: UIViewController {
#IBOutlet weak var picture: UIImageView!
#IBOutlet weak var senderLbl: UILabel!
#IBOutlet weak var recieverLbl: UILabel!
#IBOutlet weak var messageLbl: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Creating tables and data in database
let imageData = UIImageJPEGRepresentation(picture.image!, 0.5)
let file = PFFile(name: "picture.jpg", data: imageData!)
let table = PFObject(className: "messages")
table["sender"] = "Akhmed"
table["reciver"] = "Bob"
table["picture"] = file
table["message"] = "Hello!"
table.saveInBackground {(success, error) -> Void in
if(success){
print("Saved successful")
} else {
print(error!)
}
}
//Recieving Data from the Server
let information = PFQuery(className: "messages")
information.findObjectsInBackground{(objects: [PFObject]?, error) -> Void in
if error == nil {
for object in objects!{
self.senderLbl.text = object["sender"] as? String
self.recieverLbl.text = object["reciver"] as? String
self.messageLbl.text = object["message"] as? String
object["picture"].getDataInBackground(...)
}
} else {
print(error!)
}
}
}
}
Down after I access the name, receiver and message string I try to access an image that has been saved on there server with:
object["picture"].getDataInBackground(block:)
However, Swift won't even autocorrect anymore after I've typed object["picture"]. I get also an error:
'Value of type "Any" has no Member 'getDataInBackground(block:)'
Any ideas what's wrong? It seems to me that Swift can't find the string picture even though the image is saved on the server under the string "picture".
You need to first cast it as a PFFfile object and then retrieve the actual image data with getDataInBackground function like this:
let imageFile = object["picture"] as? PFFile
imageFile?.getDataInBackground (block: { (data, error) -> Void in
if error == nil {
if let imageData = data {
self.myImage = UIImage(data:imageData)
}
}
})

Unexpectedly found nil while unwrapping an optional value when loading tableView

I've been on stack for a while now but never needed to ask a question as I've always found the answers after some searching, but now I'm stuck for real. I've been searching around and going through some trial and error for an answer and I keeping getting the same error. I'm basically making a profile page with a tableView on the bottom half of the screen. The top half is loading fine filling in the current user's information. All connections to the view controller and cell view controller seem good. The table view, however, will appear with no data and crash while loading with the fatal error:
unexpectedly found nil while unwrapping an optional value.
I also believe the cellForRowAtIndexPath is not being called at all because "test" is not printing to the logs.
I'm using the latest versions of Swift and Parse.
I'm relatively new to swift so I'll go ahead and post my entire code here and any help at all is appreciated.
import UIKit
import Parse
import ParseUI
class profileViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet var tableView: UITableView!
#IBOutlet var profilePic: UIImageView!
#IBOutlet var userName: UILabel!
#IBOutlet var userBio: UILabel!
var image: PFFile!
var username = String()
var userbio = String()
var content = [String]()
#IBAction func logout(sender: AnyObject) {
PFUser.logOut()
let Login = storyboard?.instantiateViewControllerWithIdentifier("ViewController")
self.presentViewController(Login!, animated: true, completion: nil)
}
override func viewDidLoad() {
super.viewDidLoad()
profilePic.layer.borderWidth = 1
profilePic.layer.masksToBounds = false
profilePic.layer.borderColor = UIColor.blackColor().CGColor
profilePic.layer.cornerRadius = profilePic.frame.height/2
profilePic.clipsToBounds = true
tableView.delegate = self
tableView.dataSource = self
self.tableView.rowHeight = 80
self.hideKeyboardWhenTappedAround()
if let nameQuery = PFUser.currentUser()!["name"] as? String {
username = nameQuery
}
if PFUser.currentUser()!["bio"] != nil {
if let bioQuery = PFUser.currentUser()!["bio"] as? String {
userbio = bioQuery
}
}
if PFUser.currentUser()!["icon"] != nil {
if let iconQuery = PFUser.currentUser()!["icon"] as? PFFile {
image = iconQuery
}
}
self.userName.text = username
self.userBio.text = userbio
if image != nil {
self.image.getDataInBackgroundWithBlock { (data, error) -> Void in
if let downIcon = UIImage(data: data!) {
self.profilePic.image = downIcon
}
}
}
// Do any additional setup after loading the view.
var postsQuery = PFQuery(className: "Posts")
postsQuery.whereKey("username", equalTo: username)
postsQuery.findObjectsInBackgroundWithBlock( { (posts, error) -> Void in
if error == nil {
if let objects = posts {
self.content.removeAll(keepCapacity: true)
for object in objects {
if object["postText"] != nil {
self.content.append(object["postText"] as! String)
}
self.tableView.reloadData()
}
}
}
})
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Potentially incomplete method implementation.
// Return the number of sections.
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete method implementation.
// Return the number of rows in the section.
print(content.count)
return content.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let profCell = self.tableView.dequeueReusableCellWithIdentifier("profCell", forIndexPath: indexPath) as! profTableViewCell
print("test")
profCell.userPic.layer.borderWidth = 1
profCell.userPic.layer.masksToBounds = false
profCell.userPic.layer.borderColor = UIColor.blackColor().CGColor
profCell.userPic.layer.cornerRadius = profCell.userPic.frame.height/2
profCell.userPic.clipsToBounds = true
profCell.userPic.image = self.profilePic.image
profCell.name.text = self.username
profCell.content.text = content[indexPath.row]
return profCell
}
}
I let it sit for a few days and I came back to realize a very dumb mistake I made. I working with around 15 view controllers right now and realized I had a duplicate of the one I posted above with the same name. I now understand why you say working with storyboards is very sticky. Though, I did not need it, I appreciate the help and I can say I learned a few things.
You probably need to register the class you are using for the custom UITableViewCell:
self.tableView.registerClass(profTableViewCell.self, forCellReuseIdentifier: "profCell")
Unless you're using prototyped cells in IB, this registration isn't done automatically for you.
As such when you call the dequeue method (with the ! forced unwrap) you're going to have issues. The dequeueReusableCellWithIdentifier:forIndexPath: asserts if you didn't register a class or nib for the identifier.
when you register a class, this always returns a cell.
The older (dequeueReusableCellWithIdentifier:) version returns nil in that case, and you can then create your own cell.
You should use a ? during the as cast to avoid the crash, although you'll get no cells!
One other reminder, you should always use capitals for a class name, ProfTableViewCell not profTableViewCell, it's just good pratice.
Much more information here in the top answer by iOS genius Rob Mayoff: Assertion failure in dequeueReusableCellWithIdentifier:forIndexPath:
You have to create a simple NSObject Class with image, username and userbio as optional values. Then you have to declare in your profileviewcontroller a var like this:
var allProfiles = [yourNSObjectClass]()
In your cellForRowAtIndexPath add:
let profile = yourNSObjectClass()
profile = allProfiles[indexPath.row]
cell.username.text = profile.username
And go on.
Use also this:
dispatch_async(dispatch_get_main_queue(), {
self.tableView.reloadData()
})
instead of this:
self.tableView.reloadData()

Vote implementation in parse

I am stuck for a very long time. I am trying to implement a vote feature in a collection view. If the user taps the button it adds one vote to parse and shows it on the label. My code does that however when I look into the parse dashboard I see that a new row is create and the number of votes is not going into the post
My code for the cell is
import UIKit
import ParseUI
import Parse
var votes = [PFObject]()
class NewCollectionViewCell: UICollectionViewCell {
var parseObject = PFObject(className: "Posts")
#IBOutlet weak var postsImageView: PFImageView!
#IBOutlet weak var postsLabel: UILabel!
#IBOutlet weak var votesLabel:UILabel?
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
postsLabel.textAlignment = NSTextAlignment.Center
print("Passing11")
}
#IBAction func vote(sender: AnyObject) {
if let votes = parseObject.objectForKey("votes") as? Int {
parseObject.setObject(votes + 1, forKey: "votes")
parseObject.saveInBackgroundWithTarget(nil, selector: nil)
votesLabel?.text = "\(votes + 1) votes"
print("Passing22")
}
else
{
parseObject.setObject(1, forKey: "votes")
parseObject.saveInBackgroundWithTarget(nil, selector: nil)
votesLabel?.text = "1 votes"
print("Passing33")
}
}}
and collection view is
if let votes = parseObject.objectForKey("votes") as? Int {
cell.votesLabel?.text = "\(votes) votes"
}
else
{
cell.votesLabel?.text = "0 votes"
}
return cell
}
How can I make it work? Thank you.
From what I remember in my Parse project. If you need to retrieve and update an existing row in Parse you need to create a PFQuery object first and retrieve the desired row using that query object. And then you can update its "vote" or whatever attribute value you want to. Kindly try that.

Table View Cell Reloading Issue

I have a table view in my Chat app that holds Users that are logged in to the application. This app is in Swift and the table view is embedded in a Navigation controller. I'm also using Parse.
When I click on a User, it sends me to a chat screen which it's suppose to do. Then when I click the Back button, it takes me back to the User table view as it should, but something strange happens. It has the Users that are logged in, but shows them twice. For example, If User1 is logged in to the app, I click on it to chat, then go back to the table view, it now shows User1 twice. If I repeat the process, it then shows User1 three times. Hopefully someone can help...
Variables:
import UIKit
// Global Variable
var userName = ""
class usersVC: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var resultsTable: UITableView!
var resultsUsernameArray = [String]()
var resultsProfileNameArray = [String]()
var resultsImageFile = [PFFile]()
override func viewDidLoad() {
super.viewDidLoad()
let theWidth = view.frame.size.width
let theHeight = view.frame.size.height
resultsTable.frame = CGRectMake(0, 0, theWidth, theHeight-64)
// PFUser.currentUser().username is part of Parse framework
userName = PFUser.currentUser()!.username!
}
Then here is the viewDidAppear where I believe is the issue:
override func viewDidAppear(animated: Bool) {
let predicate = NSPredicate(format: "username != '"+userName+"'")
var query = PFQuery(className: "_User", predicate: predicate)
var theObjects = query.findObjects()
for object in theObjects! {
// object.username is the name of the username class in Parse, as well as "profileName" and "photo"
self.resultsUsernameArray.append(object["username"] as! String)
self.resultsProfileNameArray.append(object["profileName"] as! String)
self.resultsImageFile.append(object["photo"] as! PFFile)
self.resultsTable.reloadData()
}
}
Not sure if this is needed but it had some of the same variables and deals with the Table View:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell : ResultsCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! ResultsCell
cell.usernameLbl.text = self.resultsUsernameArray[indexPath.row]
cell.usernameLbl.hidden = true
cell.profileNameLbl.text = self.resultsProfileNameArray[indexPath.row]
resultsImageFile[indexPath.row].getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
let image = UIImage(data: imageData!)
cell.profileImg.image = image
}
}
return cell
}
Let me know if more code is needed!
Thank you,
Jack
You should change your viewDIdAppear() method little bit way like this,
override func viewDidAppear(animated: Bool) {
let predicate = NSPredicate(format: "username != '"+userName+"'")
var query = PFQuery(className: "_User", predicate: predicate)
var theObjects = query.findObjects()
self.resultsUsernameArray.removeAll(keepCapacity: true)
self.resultsProfileNameArray.removeAll(keepCapacity: true)
self.resultsImageFile.removeAll(keepCapacity: true)
for object in theObjects! {
// object.username is the name of the username class in Parse, as well as "profileName" and "photo"
self.resultsUsernameArray.append(object["username"] as! String)
self.resultsProfileNameArray.append(object["profileName"] as! String)
self.resultsImageFile.append(object["photo"] as! PFFile)
self.resultsTable.reloadData()
}
}
HTH, Enjoy Coding !!

fatal error: unexpectedly found nil while unwrapping an Optional value using cloudkit

I keep getting the following error :
fatal error: unexpectedly found nil while unwrapping an Optional value
and I guess I just don't understand why. Can someone please help me find my mistake? Is it that variable results is optional?
The error keeps pointing to a line in viewDidLoad(), I commented where. Thanks.
//
// ViewController.swift
// Physics Help!
//
// Created by Sam Hanson on 2/8/15.
// Copyright (c) 2015 Sam Hanson. All rights reserved.
//
import UIKit
import CloudKit
class ViewController: UIViewController {
//VARIABLES********************************************************
#IBOutlet var c1Answer: UILabel!
#IBOutlet var questions: UILabel!
var resultsOfDB : String = ""
var indexes : [Int] = []
var counter : Int = 0
var newStr : String = ""
//*****************************************************************
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.questions.text = String(getNewQbutton()) //error points to here*********
}
//load the answers, grab them from the cloud base
#IBAction func loadAnswers() {
let container = CKContainer.defaultContainer()
var publicDB = container.publicCloudDatabase
let myQuery = CKQuery(recordType: "QuestionsTable", predicate: NSPredicate(value: true))
publicDB.performQuery(myQuery, inZoneWithID: nil){
results, error in
if error != nil {
println(error)
}
else
{
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.c1Answer.text = results.description
println(results.description)
})
}
}
}
#IBAction func getNewQbutton() {
let container = CKContainer.defaultContainer()
var publicDB = container.publicCloudDatabase
let myQuery = CKQuery(recordType: "QuestionsTable", predicate: NSPredicate(value: true))
publicDB.performQuery(myQuery, inZoneWithID: nil){
results, error in
if error != nil {
println(error)
}
else
{
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.resultsOfDB = results.description
//for each character in resultsOfDB
for character in self.resultsOfDB{
if(character == "\""){
self.indexes.append(self.counter)
}
self.counter++
}
self.newStr = self.resultsOfDB.substringWithRange(Range<String.Index>(start: advance(self.resultsOfDB.startIndex, self.indexes[0] + 1), end: advance(self.resultsOfDB.endIndex, -(self.counter - self.indexes[1]))))
self.questions.text = self.newStr
})
}
self.counter = 0
}
}
There can be two reasons for this problem:
1.
This can mean that you are trying to call a function (text?) of an object (questions?) which is not initialized.
My guess is that questions is not initialized. So, when your call questions.text, you are calling text function on a nil outlet.
Make sure that your outlets questions are hooked up properly in the storyboard (you should see a circle near your #IBOutlet). Also, make sure you haven't set up multiple connections to your outlet.
2.
Your function getNewQbutton is an #IBAction that returns nothing. So the statement String(getNewQbutton()) doesn't make a lot of sense. Since your function getNewQbutton has no return type (and is an #IBOutlet), you are probably giving nil to String(). That may be the second reason of this issue.

Resources