ios Firebase - segue data in a "details post" Controller - ios

Question

Here is my situation:
I have a controller "Feed" which list multiple posts via a table ( a title and image) from Firebase.
On touch of a button, it bring to a "Feed Details" controller, where I would like the data ( title image and caption) from the post clicked previously (parent) being display. ( see screenshot 2)
At the moment nothing is being fetch when I arrive to the feed details controllers ...
How is it possible to fetch the details from the item click previously ??
Currently this is my feed controller:
//
// FeedVC.swift
// MobileAppDemo
//
// Created by Mikko Hilpinen on 31.10.2016.
// Copyright © 2016 Mikkomario. All rights reserved.
//
import UIKit
import FirebaseAuth
import FirebaseDatabase
import FirebaseStorage
import SwiftKeychainWrapper
import SwiftyJSON
class FeedVC: UIViewController, UITableViewDataSource, UIImagePickerControllerDelegate, UINavigationControllerDelegate
{
#IBOutlet weak var addImageView: UIImageView!
#IBOutlet weak var feedTableView: UITableView!
#IBOutlet weak var titleInputView: InputTextView!
#IBOutlet weak var captionInputView: InputTextView!
private var posts = [Post]()
private var imagePicker = UIImagePickerController()
private var imageSelected = false
private var readPosts: ObserveTask?
override func viewDidLoad()
{
super.viewDidLoad()
imagePicker.delegate = self
imagePicker.allowsEditing = true
feedTableView.dataSource = self
feedTableView.rowHeight = UITableViewAutomaticDimension
feedTableView.estimatedRowHeight = 320
readPosts = Post.observeList(from: Post.parentReference.queryOrdered(byChild: Post.PROPERTY_CREATED))
{
posts in
self.posts = posts.reversed()
self.feedTableView.reloadData()
}
}
func numberOfSections(in tableView: UITableView) -> Int
{
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return posts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
if let cell = tableView.dequeueReusableCell(withIdentifier: "MessageCell", for: indexPath) as? MessageCell
{
let post = posts[indexPath.row]
cell.configureCell(tableView: tableView, post: post)
return cell
}
else
{
fatalError()
}
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any])
{
if let image = info[UIImagePickerControllerEditedImage] as? UIImage
{
addImageView.image = image
imageSelected = true
}
picker.dismiss(animated: true, completion: nil)
}
#IBAction func selectImagePressed(_ sender: AnyObject)
{
present(imagePicker, animated: true, completion: nil)
}
#IBAction func postButtonPressed(_ sender: AnyObject)
{
guard let caption = captionInputView.text, !caption.isEmpty else
{
// TODO: Inform the user
print("POST: Caption must be entered")
return
}
guard let title = titleInputView.text, !title.isEmpty else
{
// TODO: Inform the user
print("POST: title must be entered")
return
}
guard let image = addImageView.image, imageSelected else
{
print("POST: Image must be selected")
return
}
guard let currentUserId = User.currentUserId else
{
print("POST: Can't post before logging in")
return
}
imageSelected = false
addImageView.image = UIImage(named: "add-image")
captionInputView.text = nil
titleInputView.text = nil
// Uploads the image
if let imageData = UIImageJPEGRepresentation(image, 0.2)
{
let imageUid = NSUUID().uuidString
let metadata = FIRStorageMetadata()
metadata.contentType = "image/jpeg"
Storage.REF_POST_IMAGES.child(imageUid).put(imageData, metadata: metadata)
{
(metadata, error) in
if let error = error
{
print("STORAGE: Failed to upload image to storage \(error)")
}
if let downloadURL = metadata?.downloadURL()?.absoluteString
{
// Caches the image for faster display
Storage.imageCache.setObject(image, forKey: downloadURL as NSString)
print("STORAGE: Successfully uploaded image to storage")
_ = Post.post(caption: caption, title: title, imageUrl: downloadURL, creatorId: currentUserId)
}
}
}
}
#IBAction func signOutButtonPressed(_ sender: AnyObject)
{
// Doesn't listen to posts anymore
readPosts?.stop()
try! FIRAuth.auth()?.signOut()
User.currentUserId = nil
dismiss(animated: true, completion: nil)
}
}
I'm using the code for the feeddetails - Which of course doesn't feet the data
My database structure look like below:
How is it possible to fetch the data in that details view ?? If anybody could explain me the process, it will be really fantastic !!
Thank you for all your time and help !!
----- EDIT: --------
Thanks to Retterdesdialogs, I've update the code and the App start, but when i click on the button linkbutton nothin happen and the App crash:
The Console display:
Could not cast value of type 'UIViewController' (0x1087f6758) to 'MobileAppDemo.FeedDetailsController' (0x104bc34a0).
I'm having now for code:
feedVC.swift ( there all the post are listed):
//
// FeedVC.swift
// MobileAppDemo
//
// Created by Mikko Hilpinen on 31.10.2016.
// Copyright © 2016 Mikkomario. All rights reserved.
//
import UIKit
import FirebaseAuth
import FirebaseDatabase
import FirebaseStorage
import SwiftKeychainWrapper
import SwiftyJSON
class FeedVC: UIViewController, UITableViewDataSource, UIImagePickerControllerDelegate, UINavigationControllerDelegate
{
#IBOutlet weak var addImageView: UIImageView!
#IBOutlet weak var feedTableView: UITableView!
#IBOutlet weak var titleInputView: InputTextView!
#IBOutlet weak var linkbutton: UIButton!
#IBOutlet weak var captionInputView: InputTextView!
private var posts = [Post]()
private var imagePicker = UIImagePickerController()
private var imageSelected = false
private var readPosts: ObserveTask?
override func viewDidLoad()
{
super.viewDidLoad()
imagePicker.delegate = self
imagePicker.allowsEditing = true
feedTableView.dataSource = self
feedTableView.rowHeight = UITableViewAutomaticDimension
feedTableView.estimatedRowHeight = 320
readPosts = Post.observeList(from: Post.parentReference.queryOrdered(byChild: Post.PROPERTY_CREATED))
{
posts in
self.posts = posts.reversed()
self.feedTableView.reloadData()
}
}
func numberOfSections(in tableView: UITableView) -> Int
{
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return posts.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
// here you need to add
{
if let cell = tableView.dequeueReusableCell(withIdentifier: "MessageCell", for: indexPath) as? MessageCell
{
let post = posts[indexPath.row]
cell.configureCell(tableView: tableView, post: post)
cell.linkbutton.tag = indexPath.row
cell.linkbutton.addTarget(self, action: #selector(FeedVC.toFeedDetailAction(_:)), for: .touchUpInside)
return cell
}
else
{
fatalError()
}
}
func toFeedDetailAction(_ sender: UIButton) {
let FeedDetailsController = self.storyboard?.instantiateViewController(withIdentifier: "FeedDetailsIdentifier") as! FeedDetailsController
FeedDetailsController.post = posts[sender.tag]
self.navigationController?.pushViewController(FeedDetailsController, animated: true)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any])
{
if let image = info[UIImagePickerControllerEditedImage] as? UIImage
{
addImageView.image = image
imageSelected = true
}
picker.dismiss(animated: true, completion: nil)
}
#IBAction func selectImagePressed(_ sender: AnyObject)
{
present(imagePicker, animated: true, completion: nil)
}
#IBAction func postButtonPressed(_ sender: AnyObject)
{
guard let caption = captionInputView.text, !caption.isEmpty else
{
// TODO: Inform the user
print("POST: Caption must be entered")
return
}
guard let title = titleInputView.text, !title.isEmpty else
{
// TODO: Inform the user
print("POST: title must be entered")
return
}
guard let image = addImageView.image, imageSelected else
{
print("POST: Image must be selected")
return
}
guard let currentUserId = User.currentUserId else
{
print("POST: Can't post before logging in")
return
}
imageSelected = false
addImageView.image = UIImage(named: "add-image")
captionInputView.text = nil
titleInputView.text = nil
// Uploads the image
if let imageData = UIImageJPEGRepresentation(image, 0.2)
{
let imageUid = NSUUID().uuidString
let metadata = FIRStorageMetadata()
metadata.contentType = "image/jpeg"
Storage.REF_POST_IMAGES.child(imageUid).put(imageData, metadata: metadata)
{
(metadata, error) in
if let error = error
{
print("STORAGE: Failed to upload image to storage \(error)")
}
if let downloadURL = metadata?.downloadURL()?.absoluteString
{
// Caches the image for faster display
Storage.imageCache.setObject(image, forKey: downloadURL as NSString)
print("STORAGE: Successfully uploaded image to storage")
_ = Post.post(caption: caption, title: title, imageUrl: downloadURL, creatorId: currentUserId)
}
}
}
}
#IBAction func signOutButtonPressed(_ sender: AnyObject)
{
// Doesn't listen to posts anymore
readPosts?.stop()
try! FIRAuth.auth()?.signOut()
User.currentUserId = nil
dismiss(animated: true, completion: nil)
}
}
and the FeedDetails.swift ( where the Detail are listed once you have clicked the button, button has class: linkbutton from the viewVC Controller:
//
// FeedDetailsController.swift
// MobileAppDemo
//
// Created by Mikko Hilpinen on 27.10.2016.
// Copyright © 2016 Mikkomario. All rights reserved.
//
import UIKit
import FBSDKCoreKit
import FBSDKLoginKit
import Firebase
import FirebaseAuth
import SwiftKeychainWrapper
fileprivate struct RegisterInfo
{
let email: String
let password: String
}
class FeedDetailsController: UIViewController
{
#IBOutlet weak var emailField: UITextField!
#IBOutlet weak var passwordField: UITextField!
var post: Post!
override func viewDidLoad()
{
super.viewDidLoad()
}
override func viewDidAppear(_ animated: Bool)
{
if User.currentUserId != nil
{
print("AUTH: USING EXISTING KEYCHAIN")
User.startTrackingCurrentUser()
performSegue(withIdentifier: "ToFeed", sender: nil)
}
else
{
print("AUTH: NO EXSTING KEYCHAIN")
}
}
override func didReceiveMemoryWarning()
{
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?)
{
print("AUTH: Preparing for segue \(segue.identifier)")
if let registrationVC = segue.destination as? RegisterVC
{
print("AUTH: Found registration VC")
if let info = sender as? RegisterInfo
{
print("AUTH: Sending email (\(info.email)) and password (\(info.password.characters.count) chars) information: ")
registrationVC.setBaseInfo(email: info.email, password: info.password)
}
}
}
#IBAction func signInButtonPressed(_ sender: UIButton)
{
if let email = emailField.text, let password = passwordField.text
{
FIRAuth.auth()?.signIn(withEmail: email, password: password)
{
(user, error) in
if let error = error
{
// TODO: Handle other errors here as well
switch FIRAuthErrorCode(rawValue: error._code)!
{
case .errorCodeUserNotFound:
print("AUTH: USER NOT FOUND -> CREATING NEW USER")
print("AUTH: Sending email \(email) and password \(password.characters.count) characters")
self.performSegue(withIdentifier: "RegisterUser", sender: RegisterInfo(email: email, password: password))
default: print("AUTH: ERROR IN EMAIL LOGIN \(error)") // TODO: Inform user
}
}
else
{
print("AUTH: EMAIL AUTH SUCCESSFUL")
User.currentUserId = user?.uid
User.startTrackingCurrentUser()
self.performSegue(withIdentifier: "ToFeed", sender: nil)
}
}
}
// TODO: Inform user that the field contents are missing
}
#IBAction func facebookButtonPressed(_ sender: UIButton)
{
// (Already logged in to FB)
if let fbAccessToken = FBSDKAccessToken.current()
{
print("AUTH: Already logged in to FB")
firebaseAuth(with: FIRFacebookAuthProvider.credential(withAccessToken: fbAccessToken.tokenString))
}
else
{
let facebookLogin = FBSDKLoginManager()
facebookLogin.logIn(withReadPermissions: ["public_profile", "email"], from: self)
{
(result, error) in
if let error = error
{
print("AUTH: UNABLE TO AUTHENTICATE WITH FACEBOOK")
print("AUTH: \(error)")
}
else if let result = result
{
if result.isCancelled
{
print("AUTH: USER CANCELLED FACEBOOK AUTH")
}
else
{
print("AUTH: FACEBOOK AUTH SUCCESS")
let credential = FIRFacebookAuthProvider.credential(withAccessToken: FBSDKAccessToken.current().tokenString)
self.firebaseAuth(with: credential)
}
}
}
}
}
fileprivate func firebaseAuth(with credential: FIRAuthCredential)
{
if FIRAuth.auth() == nil
{
print("AUTH: NO AUTH SERVICE AVAILABLE")
}
FIRAuth.auth()?.signIn(with: credential)
{
(user, error) in
if let error = error
{
print("AUTH: UNABLE TO AUTHENTICATE TO FIREBASE")
print("AUTH: \(error)")
}
else
{
if let user = user
{
print("AUTH: SUCCESSFULLY AUTHENTICATED WITH FIREBASE")
// Updates current user data
var userName = "User"
var image: UIImage?
if let retrievedName = user.displayName
{
userName = retrievedName
}
if let retrievedImageUrl = user.photoURL
{
if let data = try? Data(contentsOf: retrievedImageUrl)
{
image = UIImage(data: data)
}
}
User.post(uid: user.uid, provider: user.providerID, userName: userName, image: image)
{
user in
User.currentUser = user
User.startTrackingCurrentUser()
self.performSegue(withIdentifier: "ToFeed", sender: nil)
}
}
}
}
}
}

Answer 1

1) you need to be able to access the button through IBOutlet or programmatically
2) set the button to the cells indexPath.row and add an action to it
let post = posts[indexPath.row]
cell.configureCell(tableView: tableView, post: post)
// here you need to add
cell.yourButton.tag = indexPath.row
cell.yourButton.addTarget(self, action: #selector(FeedViewController.toFeedDetailAction(_:)), for: .touchUpInside)
return cell
3) when you then press the button you can identify your feed, because you have the button tag, so you know the feed from your Posts-Array
func toFeedDetailAction(_ sender: UIButton) {
let feedDetailsViewController = self.storyboard?.instantiateViewController(withIdentifier: "FeedDetailsIdentifier") as! FeedDetailsViewController
feedDetailsViewController.post = posts[sender.tag]
self.navigationController?.pushViewController(feedDetailsViewController, animated: true)
}
4) in your FeedDetailsViewController add
var post: Post!
5) in FeedDetailsViewController do what ever you want with the post
Hope this helps :)