Retrieving image from firebase? (swift) - swift

Question

So i have a firebase structure like the pic below
Now i want to retrieve that image file that i've uploaded. to decode the base64String and show it. Every user can make a post and the information that will be sended to firebase has a description etc. and also have an image. now i tried to retrieve it whit this codes but nothing did work.
var REF_LIST = Firebase(url: "\(URL_BASE)/listItems")
REF_LIST.observeEventType(FEventType.Value, withBlock: { snapshot in
let image = snapshot.value.objectForKey("images") as! String
but this already gave me a nil error on that line, so i couldn't even decode. i think i understand why it's giving me a nil error, there is no images in listItems on firebase, you first have the unique ID and then the specs with images in. now i don't now how i can retrieve that information from that unique ID?
UPDATE:
the tableViewController what will receive the data from firebase:
import UIKit
import FBSDKLoginKit
import Alamofire
import Firebase
class ListVC: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var tableView: UITableView!
var lists = [List]()
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
dispatch_async(backgroundQueue, {
self.initObservers()
})
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
self.tableView.reloadData()
}
func initObservers() {
LoadingOverlay.shared.showOverlay(self.view)
DataService.ds.REF_LISTS.observeEventType(.Value, withBlock: { snapshot in
print(snapshot.value)
self.lists = []
if let snapshots = snapshot.children.allObjects as? [FDataSnapshot] {
for snap in snapshots {
print("SNAP: \(snap)")
if let listDict = snap.value as? Dictionary<String, AnyObject> {
let key = snap.key
let list = List(listKey: key, dictionary: listDict)
self.lists.insert(list, atIndex:0)
}
}
}
self.tableView.reloadData()
LoadingOverlay.shared.hideOverlayView()
})
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return lists.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if let cell = tableView.dequeueReusableCellWithIdentifier("ListCell") as? ListCell {
let list = self.lists[indexPath.row]
cell.request?.cancel()
cell.configureCell(list)
return cell
} else {
return ListCell()
}
}
}
the addController which post the data to firebase:
import UIKit
import Firebase
import Alamofire
import FBSDKCoreKit
class AddVC: UIViewController, UITextFieldDelegate, UITextViewDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
#IBOutlet weak var addTitle: UITextField!
#IBOutlet weak var addDescription: UITextView!
#IBOutlet weak var addLocation: UITextField!
#IBOutlet weak var placeholderLbl: UILabel!
#IBOutlet weak var freeSwitch: UISwitch!
#IBOutlet weak var tradeSwitch: UISwitch!
#IBOutlet weak var imageSelectorImg: UIImageView!
#IBOutlet weak var overlayView: UIView!
var currentUsername = ""
var imageSelected = false
var imagePicker: UIImagePickerController!
var base64String: NSString = ""
override func viewDidLoad() {
super.viewDidLoad()
addTitle.delegate = self
addDescription.delegate = self
addLocation.delegate = self
imagePicker = UIImagePickerController()
imagePicker.delegate = self
getCurrentUser()
hideKeyboardWhenTappedAround()
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
addTitle.text = ""
addDescription.text = ""
addLocation.text = ""
freeSwitch.setOn(false, animated: false)
tradeSwitch.setOn(false, animated: false)
placeholderLbl.hidden = false
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func getCurrentUser() {
DataService.ds.REF_USER_CURRENT.observeEventType(FEventType.Value, withBlock: { snapshot in
let currentUser = snapshot.value.objectForKey("username") as! String
print("Username: \(currentUser)")
self.currentUsername = currentUser }, withCancelBlock: { error in
print(error.description)
})
}
func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {
imagePicker.dismissViewControllerAnimated(true, completion: nil)
imageSelectorImg.image = image
dispatch_async(backgroundQueue, {
let uploadImage = image
let imageData = UIImageJPEGRepresentation(uploadImage, 0.5)
self.base64String = imageData!.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
})
imageSelected = true
}
#IBAction func selectImage(sender: UITapGestureRecognizer) {
presentViewController(imagePicker, animated: true, completion: nil)
}
func postToFirebase() {
// LoadingOverlay.shared.showOverlay(self.overlayView)
var post: Dictionary<String, AnyObject> = ["username": self.currentUsername, "description": self.addDescription.text!, "title": self.addTitle.text!, "location": self.addLocation.text!, "images": self.base64String]
if self.freeSwitch.on && self.tradeSwitch.on {
post["tradeOption"] = "Gratis/Te ruil"
} else if self.freeSwitch.on {
post["tradeOption"] = "Gratis"
} else if self.tradeSwitch.on {
post["tradeOption"] = "Te ruil"
}
let firebasePost = DataService.ds.REF_LISTS.childByAutoId()
firebasePost.setValue(post)
}
#IBAction func postListItem(sender: AnyObject) {
if let addTitle = addTitle.text where addTitle != "", let addDescription = addDescription.text where addDescription != "", let addLocation = addLocation.text where addLocation != "" {
dispatch_async(backgroundQueue, {
self.postToFirebase()
dispatch_async(dispatch_get_main_queue(), { () -> Void in
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let listVC = storyboard.instantiateViewControllerWithIdentifier("TBC") as! UITabBarController
listVC.selectedIndex = 1
self.presentViewController(listVC, animated: false, completion: nil)
})
})
}
}
func textViewDidBeginEditing(textView: UITextView) {
placeholderLbl.hidden = true
}
func textViewDidEndEditing(textView: UITextView) {
if textView.text == "" {
placeholderLbl.hidden = false
}
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
}
and the swift file to configure the cell:
import UIKit
import Alamofire
import Firebase
class ListCell: UITableViewCell {
#IBOutlet weak var listImg: UIImageView!
#IBOutlet weak var listTitle: UILabel!
#IBOutlet weak var listTradeOption: UILabel!
#IBOutlet weak var listLocation: UILabel!
#IBOutlet weak var headImg: UIImageView!
var list: List!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
func retrieveImages() {
DataService.ds.REF_LISTS.observeEventType(FEventType.Value, withBlock: { snapshot in
if let snapshots = snapshot.children.allObjects as? [FDataSnapshot] {
for snap in snapshots {
let image = snap.value.objectForKey("images") as! String
let decodedData = NSData(base64EncodedString: image, options: NSDataBase64DecodingOptions.IgnoreUnknownCharacters)
let decodedImage = UIImage(data: decodedData!)
self.headImg.image = decodedImage
}
}
})
}
func configureCell(list: List) {
self.list = list
self.listTitle.text = list.listTitle
self.listTradeOption.text = list.listTradeOption
self.listLocation.text = list.listLocation
retrieveImages()
}
}
also the list Model file:
import Foundation
import Firebase
class List {
private var _listTitle: String!
private var _listDescription: String!
private var _listTradeOption: String!
private var _listLocation: String!
private var _listImageURL: String?
private var _listKey: String!
private var _listRef: Firebase!
var listTitle: String? {
return _listTitle
}
var listDescription: String? {
return _listDescription
}
var listTradeOption: String? {
return _listTradeOption
}
var listLocation: String? {
return _listLocation
}
var listKey: String {
return _listKey
}
var listImageURL: String? {
return _listImageURL
}
init(title: String, description: String, tradeOption: String, location: String, listImageURL: String?) {
self._listTitle = title
self._listDescription = description
self._listTradeOption = tradeOption
self._listLocation = location
self._listImageURL = listImageURL
}
init(listKey: String, dictionary: Dictionary<String, AnyObject>) {
self._listKey = listKey
if let title = dictionary ["title"] as? String {
self._listTitle = title
}
if let desc = dictionary ["description"] as? String {
self._listDescription = desc
}
if let trade = dictionary ["tradeOption"] as? String {
self._listTradeOption = trade
}
if let loc = dictionary ["location"] as? String {
self._listLocation = loc
}
if let imgUrl = dictionary["images"] as? String {
self._listImageURL = imgUrl
}
self._listRef = DataService.ds.REF_LISTS.childByAppendingPath(self._listKey)
}
}
i've got also a DataServicefile, where i create a user by unique ID with this code:
var REF_USER_CURRENT: Firebase {
let uid = NSUserDefaults.standardUserDefaults().valueForKey(KEY_UID) as! String
let user = Firebase(url: "\(REF_BASE)").childByAppendingPath("users").childByAppendingPath(uid)
return user!
}
func createFirebaseUser(uid: String, user: Dictionary<String, String>) {
REF_USERS.childByAppendingPath(uid).setValue(user)
}
i know it's a lot but maybe the best way to help :)

Answer 1

Try editing this in List Cell
var imageURL = String()
func retrieveImages() {
let decodedData = NSData(base64EncodedString: imageURL, options: NSDataBase64DecodingOptions.IgnoreUnknownCharacters)
let decodedImage = UIImage(data: decodedData!)
self.headImg.image = decodedImage
}
func configureCell(list: List) {
self.list = list
self.listTitle.text = list.listTitle
self.listTradeOption.text = list.listTradeOption
self.listLocation.text = list.listLocation
self.imageURL = list.listImageURL //you already had the image url for that specific cell
retrieveImages()
}

Answer 2

Storing and accessing images using base64String in firebase is not an
efficient way, instead of that we can use FirebaseStorage (Google cloud storage
bucket) for uploading images to Firebase and it will provide us
download URL for a particular image. We can store that URL into our database simply in a string format and access it whenever we
required and then download the corresponding image from that URL by
using SDWebImage.
Refer below link for integrating FirebaseStorage into your project: https://firebase.google.com/docs/storage/ios/upload-files