I do hope all is well. I am new to Swift. I am building a shell for 2 social app ideas of mine. I have successfully completed login, signup, logout and minimal querying using Parse. Up until now, I have been progressing, however I have reached a mental block.
I created a User Profile ViewController that queries the current user's information from the database and initially displays the results on the in the controller; First Name, Last Name, and etc.
I also created an Edit Profile ViewController that enables the user to update their profile information and logout. So far I have been able to submit the changes to the database, however I am having a hard time having the UILabels and Text Fields update to display the new values.
Some additional insight: Becuase my main view that users are redirected to after successful signin/registration is embedded in a navigation controller which means the navigation bar is inferred.
Please help me!
This is the code for my UserProfileViewController. Please let me knwo if I need to clarify.
override func viewDidLoad() {
super.viewDidLoad()
//---------------------------------------
//User Profile View - this can go between viewDidLoad and viewDidAppear functions.
//---------------------------------------
let userImageFile = PFUser.currentUser()["userProfileImage"] as PFFile
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData!, error: NSError!) -> Void in
if error == nil {
var image = UIImage(data:imageData)
self.currentUserProfilePicture.image = image
}
}
var query = PFUser.query()
query.whereKey("objectId", equalTo: PFUser.currentUser().objectId)
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]!, error: NSError!) -> Void in
if error == nil {
let user = PFUser.currentUser()
var firstname = PFUser.currentUser()["firstName"]! as String
var lastname = PFUser.currentUser()["lastName"]! as String
var aboutMe = PFUser.currentUser()["aboutMe"]! as String
self.firstName.text = firstName
self.lastName.text = lastname
self.aboutMe.text = aboutMe
}
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
override func viewDidAppear(animated: Bool) {
}
Hi and welcome to swift.
Are you using the prepareForSegue, for sending data between ViewControllers?
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "yourIdentifier" //you set the identifier in the storyboard
{
var vc = segue.destinationViewController as! YourDestinationViewController //the class of the destination view controller
vc.someValue = value
vc.otherValue = otherValue
vc.dataArray = array //here you set the values in the destination view controller
}
}
Related
I have a push segue on my StoryBoard which is named toGuestVC.
I use that to segue to the next ViewController in my didSelectRowAtIndexPath method like so:
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let username = followUsernameArray[indexPath.row]
performSegue(withIdentifier: SG_TO_GUEST_VIEW_CONTROLLER, sender: username)
}
Then in my prepareForSegue:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == SG_TO_GUEST_VIEW_CONTROLLER {
if let nextVC = segue.destination as? GuestCollectionVC, let sender = sender as? String {
print("PRINTING NEXT VC: \(nextVC)") //This prints out the memory address. Not sure if this is what you meant by print nextVC.
nextVC.guestUser = sender
}
}
}
For some reason this line in my prepareForSegue is not running:
nextVC.guestUser = sender.username
When I try to print out the value guestUser in my nextViewController the value of guestUser is nil. But when I print out the value of sender in my prepareForSegue method it is not nil.
So is my sender value not being passed to the next ViewController? I can't find a solution to this problem any ideas?
GuestCollectionVC Implementation:
import UIKit
import Parse
private let reuseIdentifier = "Cell"
class GuestCollectionVC: UICollectionViewController {
var guestUser: String!
override func viewDidLoad() {
super.viewDidLoad()
print("PRINTING SELF IN GuestCollectionVC: \(self)")
loadPosts()
}
func loadPosts() {
//Load posts query
let query = PFQuery(className: PF_POSTS_CLASS)
query.limit = postCount
//Getting error here below this comment when I use guestUser since it is nil
query.whereKey(PF_POSTS_USERNAME_COLUMN, equalTo: guestUser)
query.findObjectsInBackground { (result: [PFObject]?, error: Error?) -> Void in
if error == nil {
if let result = result {
self.uuidOfPosts.removeAll(keepingCapacity: false)
self.imageArrayOfPFFIle.removeAll(keepingCapacity: false)
for postObject in result {
if let uuid = postObject[PF_POSTS_UUID_COLUMN] as? String, let pic = postObject[PF_POSTS_PIC_COLUMN] as? PFFile {
self.uuidOfPosts.append(uuid)
self.imageArrayOfPFFIle.append(pic)
}
}
self.collectionView?.reloadData()
}
}else if error != nil {
print("ERROR FROM GUEST COLLECTION VC FROM loadPosts FUNCTION: \(error?.localizedDescription)")
}
}
}
}
So this is my implementation in the GuestViewController. In my loadPosts method where I used the variable guestUser I am getting the error:
fatal error: unexpectedly found nil while unwrapping an Optional value
From console printing
PRINTING NEXT VC: "InstagramClone.GuestCollectionVC: 0x7a6c5cc0"
PRINTING SELF IN GuestCollectionVC: "InstagramClone.GuestCollectionVC: 0x7a6c5100"
it's now obvious that hidden unexpected instance of GuestCollectionVC was created. So, there are different errors occurs depending on order of this two objects invoke their viewDidLoad method (can be any order). Also there are can be other errors in nextVC viewDidLoad method, but this is other story for other question.
You got this problems because you created action segue, that works automatically on cell click (hidden view controller created), and at the same time you are perform this segue in code, creating second controller nextVC.
To solve issue, you should find and remove that segue and add new one, not action segue from some element of your view controller, but "empty" segue between view controllers. To create segue of this type you should select first view controller, hold "control" key and start dragging to next view controller from yellow square on top of first view controller (that symbol controller itself), choose "show", and set identifier.
Since I don't have the full context of the values within your tableView method I can only speculate. That said, the sender you're passing in should be the view controller:
performSegue(withIdentifier: "toGuestVC", sender: username)
You're passing in a value called username which looks to be a string value? It should be something like:
performSegue(withIdentifier: "toGuestVC", sender: self)
where self is your view controller. If you're passing in a string value to sender then in your prepareForSegue method then sender does not have a property called username sender actually is username. Therefore you should pass the value elsewhere:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let indexPath = self.tableView.indexPathForSelectedRow
if let nextVC = segue.destination as? GuestCollectionVC {
nextVC.guestUser = followUsernameArray[indexPath.row]
}
}
Edit 1: I've restructured my ViewControllers to make it easier to get what I want done.
Edit 2: I realized something major was missing while adding notes to my code, another function overrides the first segue.
This ViewController is where the annotation is created; all I need from this view is for the touchMapCoordinates to be transferred to the other ViewController so I can save the PFGeoPoint in an array.
Edit 3
After long work on understanding what is going on and simplifying the code, i've came down to the final conclusion based off of Swift- variable not initialized before use (but it's not used) , that the current method that I'm trying to use will not work in any case or scenario due to it saving Asynchronously. If anyone knows a work around, then you have officially done something that hasn't been done before :).
Error that is showing up is
Constant 'boi' used before being initialized
Subclass that is declared in Appdata to be used anywhere within the project
import Foundation
import Parse
import MapKit
class MyAnnotation: PFObject, PFSubclassing, MKAnnotation {
// MARK: - Properties
#NSManaged var location: PFGeoPoint
// MARK: - Initializers
init(coordinate: CLLocationCoordinate2D) {
super.init()
self.location = PFGeoPoint(latitude: coordinate.latitude, longitude: coordinate.longitude)
print(location)
}
override class func initialize() {
struct Static {
static var onceToken : dispatch_once_t = 0;
}
dispatch_once(&Static.onceToken) {
self.registerSubclass()
}
}
// MARK: - PFSubclassing protocol
static func parseClassName() -> String {
return "AnnotationPins"
}
// MARK: - MKAnnotation protocol
var coordinate: CLLocationCoordinate2D {
return CLLocationCoordinate2DMake(location.latitude, location.longitude)
}
var title: String? = "Start Topic"
}
Where the code will all be saved asynchronously together
} else {
let imageData = UIImagePNGRepresentation(self.galleryCameraImage.image!)
let parseImageFile = PFFile(name: "upload_image.png", data: imageData!)
let boi : MyAnnotation
let textTitleandText = PFObject(className: "AnnotationPins")
textTitleandText["textTopic"] = userTopic.text
textTitleandText["textInformation"] = userText.text
textTitleandText["userUploader"] = PFUser.currentUser()
textTitleandText["imageFile"] = parseImageFile!
textTitleandText["location"] = boi.location
textTitleandText.saveInBackgroundWithBlock { (success: Bool, error: NSError?) -> Void in
if error == nil {
If anyone could help it would be really appreciated!
Over ride prepareForSegue method like below.
override func prepareForSegue(segue: UIStoryboardSegue, sender:
AnyObject?) {
if segue.identifier == "SegueID" {
let destinationVC = segue.destinationViewController as! DestinationViewController
// Create property in destinationView controller & assign required data from here.
}
}
Hope it helps.
Lets treat your Location data as a normal data to be transferred through segues.
You can use this method to configure your destination View controller variable(same type) that will hold your location data.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
//check your segue name
if segue.identifier == "YourSegueIdentifier" {
let destinationVC = segue.destinationViewController as! YourDestinationViewController
destinationVC.locationVariableInDestinationVC = locationVariableInCurrentVC
}
}
Above is the simplest way to pass data via segue, you can use the same approach for your location data too.
Hope that helps!!
Update: Based on your updated code
Move func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {} out of your handleLongPress function. PrepareForSegue function gets called automatically when there is any navigation happening through segues..
If you want to initiate a segue navigation programatically then assign a identifier to the segue and just call self.performSegueWithIdentifier("YourSegueIdentifier", sender: nil)
I've created a user profile screen, and when loaded, the data takes a few seconds to appear. I'm looking for a more elegant solution.
Here's the view controller in the storyboard:
As you can see, there is placeholder text. The issue is that this text appears very briefly when this screen is loaded (before the data is retrieved from the database).
Here is what the screen looks like when the data is fully loaded:
I've seen that an Activity Indicator on the previous screen may be a good solution. Can anyone verify this and point me to a good SWIFT tutorial or Stack Overflow solution?
UPDATE:
I'm loading the data on the previous View Controller as suggested. The issue that I'm running into is that the constants which I store my data are not accessible in prepareForSegue -
override func performSegueWithIdentifier(identifier: String, sender: AnyObject?) {
let query = PFQuery(className:"UserProfileData")
query.whereKey("username", equalTo: (PFUser.currentUser()?.username)!)
query.findObjectsInBackgroundWithBlock { (objects: [PFObject]?, error: NSError?) -> Void in
if error == nil {
if let objects = objects! as? [PFObject] {
for object in objects {
let yourselfObject = object["yourself"] as! String?
let brideGroomObject = object["brideGroom"] as! String?
}
}
} else {
print(error)
}
}
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "RSVPToUserProfile" {
if let destination = segue.destinationViewController as? UserProfileViewController {
destination.yourselfPassed = yourselfObject
destination.brideGroomPassed = brideGroomObject
}
}
}
This one is actually very simple... Just remove the placeholder text from the storyboard. That way it won't "appear very briefly."
If you don't like the idea of a blank screen, then move the loading code to the place where the view is being presented. Don't present the view until after the loading code is complete. You will have to pass the data to the view controller at presentation time if you do this.
-- EDIT --
Do not override performSegueWithIdentifier:sender:! Doing so will not accomplish your goal.
I say again. Move the loading code to the place where you are calling perform segue, and delay the call until after your data is loaded. (I.E. move the perform segue call into the findObjectsInBackgroundWithBlock block after you get the items.
I am logging in my users using Parse. As my app opens my LaunchVieWController determines whether users are already signed in or not:
override func viewDidLoad() {
super.viewDidLoad()
//Make sure cached users don't have to log in every time they open the app
var currentUser = PFUser.currentUser()
println(currentUser)
if currentUser != nil {
dispatch_async(dispatch_get_main_queue()) {
self.performSegueWithIdentifier("alreadySignedIn", sender: self)
}
} else {
dispatch_async(dispatch_get_main_queue()) {
self.performSegueWithIdentifier("showSignUpIn", sender: self)
}
}
}
If users are already signed in they are taken to the table view described below. If they are not logged in, they are taken to a view in which they can go to the signup view or the login view.
My signup works perfectly fine, and signs up users and then redirects them to the table view.
Here is the signup function (it is in a separate controller from the login function):
func processSignUp() {
var userEmailAddress = emailAddress.text
var userPassword = password.text
// Ensure username is lowercase
userEmailAddress = userEmailAddress.lowercaseString
// Add email address validation
// Start activity indicator
activityIndicator.hidden = false
activityIndicator.startAnimating()
// Create the user
var user = PFUser()
user.username = userEmailAddress
user.password = userPassword
user.email = userEmailAddress
user.signUpInBackgroundWithBlock {
(succeeded: Bool, error: NSError?) -> Void in
if error == nil {
dispatch_async(dispatch_get_main_queue()) {
self.performSegueWithIdentifier("signInToNavigation", sender: self)
}
} else {
self.activityIndicator.stopAnimating()
if let message: AnyObject = error!.userInfo!["error"] {
self.message.text = "\(message)"
}
}
}
}
My login function looks like so:
#IBAction func signIn(sender: AnyObject) {
var userEmailAddress = emailAddress.text
userEmailAddress = userEmailAddress.lowercaseString
var userPassword = password.text
PFUser.logInWithUsernameInBackground(userEmailAddress, password:userPassword) {
(user: PFUser?, error: NSError?) -> Void in
if user != nil {
dispatch_async(dispatch_get_main_queue()) {
self.performSegueWithIdentifier("signInToNavigation", sender: self)
}
} else {
if let message: AnyObject = error!.userInfo!["error"] {
self.message.text = "\(message)"
}
}
}
}
After users log in they are sent to a table view. In that table view I am trying to access the current user object in the following function, as I want to load different data based on who the user is:
override func queryForTable() -> PFQuery {
var query = PFQuery(className:"MyClass")
query.whereKey("userID", equalTo: PFUser.currentUser()!)
return query
}
When I try to log in with a user I get thrown the following error: "fatal error: unexpectedly found nil while unwrapping an Optional value". It seems like the PFUser.currentUser() object is nil.
When users are sent to the table view after signing up the PFUser.currentUser() object is set and works perfectly.
My guess is that this is because of the fact that the PFUser.logInWithUsernameInBackground is happening in the background and that my query is trying to get the PFUser.currentUser() object before it has been loaded. Is there anyway I can work around this issue? In the table view the value of PFUser.currentUser() is needed to load the table data. Can I somehow make sure that PFUser.currentUser() gets assigned with the current user object before the function gets called (for example, by not loading in users in the background thread)?
All help is much appreciated!
EDIT: I've updated this post with some more of my code to help highlight any bug that I may be missing.
I discovered that this problem appeared because the segue signInToNavigation was wired from the Login-button, instead from the login view controller itself. This resulted in the segue being executed before the login function was executed, and therefore the PFUser.currentUser()object was not yet assigned when the table view loaded. I solved this by rewiring the segues. Stupid slip-up on my side.
Thanks to Ryan Kreager and Wain for taking time to help me figure out this issue!
You can try checking if PFUser.currentUser() != nil instead to make sure it's being set right after login. If it's not being set right off the bat, you know there is a deeper login problem.
Also, try removing the dispatch_async(dispatch_get_main_queue()){ wrapper around your call to the segue.
It's unnecessary (logInWithUsernameInBackground already returns to the main thread) and I have a hunch that it's creating a racing condition where the local object is not being set first because Parse can't do any post-call cleanup since you're going right for the main thread.
I want to make such thing:
On one ViewControleer I'm making a query to Parse.com, where I'm sending objects fields to Label.Text. By clicking one button objects randomly changes, by clicking another one- next ViewController is opening. Just imagine Tinder - on the first VC I swiping girls, on the new one chat is opening, with the girl's name in the head of the NavigatorItem
So I want to send Object Field "Name" that I'm using in that view to another without other query.
I don't know, whether I can do it via segue, or protocol. Can U somehow help me with implementation?
here is the code of my random function
func retriveJobData() {
var query: PFQuery = PFQuery(className: "Jobs")
query.getObjectInBackgroundWithId("AUeuvj0zk2") {
(newJobObject: PFObject?, error: NSError?) -> Void in
if error == nil && newJobObject != nil {
println(newJobObject)
if let newJobObject = newJobObject {
self.PrcieTextField.text = newJobObject["jobPrice"] as? String
self.DateTextField.text = newJobObject["jobDate"] as? String
self.DescriptionTextField.text = newJobObject["jobDescription"] as? String
}
} else {
println(error)
}
}
}
I want to send newJobObject["jobName"] to NavigatorItemName of another ViewController
you can override prepareForSegue for this purpose:
override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
if (segue.identifier == "yourSegueIdentifier") {
// pass data to next view
}
}
Assuming you have some method that triggers a push to the new viewController and that you're using the storyboard, call performSegue using the identifier you set up in the storyboard
#IBAction func buttonPressed(sender: UIButton!) {
performSegueWithIdentifier("identifier", sender: nil)
}
Then override prepareForSegue and pass in the string
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "identifier" {
let controller = segue.destinationViewController as! ViewController
controller.jobName = someWayThatYouRetrieveNewJobObjectName
}
Then in ViewController ensure you have a property for jobName
var jobName:String! //declare this as an optional instead if needed
And set the navigation title
navigationItem.title = jobName