I have two services that bring me data, the first one gets me longitude and latitude. I send them to google location services to get me a "formatted_address", then fill this formatted address into a TableView
func getData(){
locDataArray.removeAll()
let url = "http://someurl/Report/v1/TripReport?UserID=101&Username=ewe2020&DeviceID=2647&FromDate=25/10/2018%2006:00%20AM&lang=ar&ToDate=25/10/2018%2009:00%20PM"
// or if you need the string
print(url)
Alamofire.request(url).responseJSON { (responseData) -> Void in
if((responseData.result.value) != nil) {
let swiftyJsonVar = JSON(responseData.result.value!)
if let data = swiftyJsonVar.stringValue.data(using: .utf8) {
if let json = try? JSON(data: data) {
for item in json["data"].arrayValue {
self.locDataArray.append(LocData(fromJson: item))
}
}
DispatchQueue.main.async{
self.getAddress()
self.table.reloadData()
}
}
}
}
}
for getting the location's long and lat
and this for google api :
for loc in self.locDataArray{
let urlComponents = URLComponents(string: "https://maps.googleapis.com/maps/api/geocode/json?latlng="+loc.fromLat!+","+loc.fromLong!+"&key=*************")!
Alamofire.request(urlComponents).responseJSON { (responseData) -> Void in
if((responseData.result.value) != nil) {
let swiftyJsonVar = JSON(responseData.result.value!)
self.locNameFrom.append((swiftyJsonVar.dictionary!["results"]?[0]["formatted_address"].string)!)
} else {
print("empty")
}
}
}
finally, in the cellForRowAt
if locNameFrom.count > 0 {
cell?.from.text = locNameFrom[indexPath.row]
}
the data is only shown after scrolling up or down.
if((responseData.result.value) != nil) {
let swiftyJsonVar = JSON(responseData.result.value!)
self.locNameFrom.append((swiftyJsonVar.dictionary!["results"]?[0]["formatted_address"].string)!)
self.table.reloadData() // <-- here you should reloadData.
}
Related
I have a problem with loading images from firebase. I have two functions. One of them collect info about user, second one load users avatar image. Unfortunately images load after function creates new user. I know it will be problem with asynchronous of Firebase but I don't know how to set up DispatchQueue to work properly. Can you help me with that?
// function that load user image in user manager class
func loadUserImage(contactUserID: String, completion: #escaping (UIImage) -> Void) {
let userID = Auth.auth().currentUser!.uid
var userImageRef = self.storage.child("\(userID)/userImage.jpg")
var image = UIImage()
if contactUserID != "" {
userImageRef = self.storage.child("\(contactUserID)/userImage.jpg")
}
userImageRef.getData(maxSize: 5 * 1024 * 1024) { (data, error) in
if let error = error {
print("Error with retrieving data: \(error.localizedDescription)")
} else {
if data?.count != 0 {
image = UIImage(data: data!)!
} else {
image = UIImage(systemName: "person.circle.fill")!
}
completion(image)
}
}
}
// function that load user in contact manager class
func loadContactList(completion: #escaping ([User]) -> Void) {
let currentUserID = Auth.auth().currentUser!.uid
db.collection("contacts")
.document(currentUserID)
.collection("userContacts")
.addSnapshotListener { (querySnapshot, error) in
var contactList = [User]()
if let error = error {
print("Error with retrieving data from DB: \(error.localizedDescription)")
} else {
if let snapshotDocuments = querySnapshot?.documents {
for document in snapshotDocuments {
let data = document.data()
let uid = data["uid"] as! String
let name = data["name"] as! String
let email = data["email"] as! String
var contact = User(email: email, name: name, userID: uid)
DispatchQueue.global().sync {
self.userService.loadUserImage(contactUserID: uid) { (image) in
contact.photoURL = image
}
}
contactList.append(contact)
contactList.sort {
$0.name < $1.name
}
completion(contactList)
}
}
}
}
}
// Function implementation in viewController
func loadContactList() {
self.contactService.loadContactList { (contactArray) in
self.contactList = contactArray
self.tableView.reloadData()
}
}
What you can do is to store the image url in the firebase database and after that create this extension:
import UIKit
let imageCache: NSCache = NSCache<AnyObject, AnyObject>()
extension UIImageView {
func loadImageUsingCacheWithUrlString(urlString: String) {
self.image = nil
if let cachedImage = imageCache.object(forKey: urlString as AnyObject) as? UIImage {
self.image = cachedImage
return
}
let url = URL(string: urlString)
if let data = try? Data(contentsOf: url!) {
DispatchQueue.main.async(execute: {
if let downloadedImage = UIImage(data: data) {
imageCache.setObject(downloadedImage, forKey: urlString as AnyObject)
self.image = downloadedImage
}
})
}
}
}
And call:
if let url = data["imgUrl"] as? String {
self.myImageView.loadImageUsingCacheWithUrlString(urlString: url)
}
For that what you need to do is to create and initialize an UIImage object. If you are working with cell classes you need to create this object in the cell.
Probably a stupid question, but I'm a beginner at this.
The below code is supposed to get book information from Google Books from a keyword search. It then goes through the results and checks if I have a matching ISBN in a Firebase database. It works, but currently can only search 40 books as that's the Google Books API maximum per search.
Fortunately, I can specify where to start the index and get the next 40 books to search as well. Unfortunately, I've been trying for hours to understand how the URLSession works. All the methods I've tried have shown me that the code after the URLSession block doesn't necessarily wait for the session to complete. So if I check if I've found any matches afterward, it might not even be done searching.
I suspect the answer is in completion handling, but my attempts so far have been unsuccessful. Below is my code with a URL setup to take various starting index values.
var startingIndex = 0
//encode keyword(s) to be appended to URL
let query = query.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
let url = "https://www.googleapis.com/books/v1/volumes?q=\(query)&&maxResults=40&startIndex=\(startingIndex)"
URLSession.shared.dataTask(with: URL(string: url)!) { (data, response, error) in
if error != nil {
print(error!.localizedDescription)
}else{
let json = try! JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [String: AnyObject]
if let items = json["items"] as? [[String: AnyObject]] {
//for each result make a book and add title
for item in items {
if let volumeInfo = item["volumeInfo"] as? [String: AnyObject] {
let book = Book()
//default values
book.isbn13 = "isbn13"
book.isbn10 = "isbn10"
book.title = volumeInfo["title"] as? String
//putting all authors into one string
if let temp = volumeInfo["authors"] as? [String] {
var authors = ""
for i in 0..<temp.count {
authors = authors + temp[i]
}
book.author = authors
}
if let imageLinks = volumeInfo["imageLinks"] as? [String: String] {
book.imageURL = imageLinks["thumbnail"]
}
//assign isbns
if let isbns = volumeInfo["industryIdentifiers"] as? [[String: String]] {
for i in 0..<isbns.count {
let firstIsbn = isbns[i]
if firstIsbn["type"] == "ISBN_10" {
book.isbn10 = firstIsbn["identifier"]
}else{
book.isbn13 = firstIsbn["identifier"]
}
}
}
//adding book to an array of books
myDatabase.child("listings").child(book.isbn13!).observeSingleEvent(of: .value, with: { (snapshot) in
if snapshot.exists() {
if listings.contains(book) == false{
listings.append(book)
}
DispatchQueue.main.async { self.tableView.reloadData() }
}
})
myDatabase.child("listings").child(book.isbn10!).observeSingleEvent(of: .value, with: { (snapshot) in
if snapshot.exists() {
if listings.contains(book) == false{
listings.append(book)
}
DispatchQueue.main.async { self.tableView.reloadData() }
}
})
}
}
}
}
SVProgressHUD.dismiss()
}.resume()
Below is my revised code:
func searchForSale(query: String, startingIndex: Int) {
directionsTextLabel.isHidden = true
tableView.isHidden = false
listings.removeAll()
DispatchQueue.main.async { self.tableView.reloadData() }
SVProgressHUD.show(withStatus: "Searching")
//clear previous caches of textbook images
cache.clearMemoryCache()
cache.clearDiskCache()
cache.cleanExpiredDiskCache()
let url = "https://www.googleapis.com/books/v1/volumes?q=\(query)&&maxResults=40&startIndex=\(startingIndex)"
URLSession.shared.dataTask(with: URL(string: url)!) { (data, response, error) in
if error != nil {
print(error!.localizedDescription)
}else{
var needToContinueSearch = true
let json = try! JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [String: AnyObject]
if json["error"] == nil {
let totalItems = json["totalItems"] as? Int
if totalItems == 0 {
SVProgressHUD.showError(withStatus: "No matches found")
return
}
if let items = json["items"] as? [[String: AnyObject]] {
//for each result make a book and add title
for item in items {
if let volumeInfo = item["volumeInfo"] as? [String: AnyObject] {
let book = Book()
//default values
book.isbn13 = "isbn13"
book.isbn10 = "isbn10"
book.title = volumeInfo["title"] as? String
//putting all authors into one string
if let temp = volumeInfo["authors"] as? [String] {
var authors = ""
for i in 0..<temp.count {
authors = authors + temp[i]
}
book.author = authors
}
if let imageLinks = volumeInfo["imageLinks"] as? [String: String] {
book.imageURL = imageLinks["thumbnail"]
}
//assign isbns
if let isbns = volumeInfo["industryIdentifiers"] as? [[String: String]] {
for i in 0..<isbns.count {
let firstIsbn = isbns[i]
//checks if isbns have invalid characters
let isImproperlyFormatted = firstIsbn["identifier"]!.contains {".$#[]/".contains($0)}
if isImproperlyFormatted == false {
if firstIsbn["type"] == "ISBN_10" {
book.isbn10 = firstIsbn["identifier"]
}else{
book.isbn13 = firstIsbn["identifier"]
}
}
}
}
//adding book to an array of books
myDatabase.child("listings").child(book.isbn13!).observeSingleEvent(of: .value, with: { (snapshot) in
if snapshot.exists() {
if listings.contains(book) == false{
listings.append(book)
needToContinueSearch = false
}
DispatchQueue.main.async { self.tableView.reloadData() }
}
})
myDatabase.child("listings").child(book.isbn10!).observeSingleEvent(of: .value, with: { (snapshot) in
if snapshot.exists() {
if listings.contains(book) == false{
listings.append(book)
needToContinueSearch = false
}
DispatchQueue.main.async { self.tableView.reloadData() }
return
}
if startingIndex < 500 {
if needToContinueSearch {
let nextIndex = startingIndex + 40
self.searchForSale(query: query, startingIndex: nextIndex)
}
}
})
}
}
}
}else{
return
}
}
SVProgressHUD.dismiss()
}.resume()
//hide keyboard
self.searchBar.endEditing(true)
}
In your completion handler if any results have been returned you end with:
DispatchQueue.main.async { self.tableView.reloadData() }
to trigger reloading of your table with the updated information. At this same point is where you could determine of there may be more results and initiate the next asynchronous URL task. In outline your code might be:
let needToContinueSearch : Bool = ...;
DispatchQueue.main.async { self.tableView.reloadData() }
if needToContinueSearch
{ // call routine it initiate next async URL task
}
(If there is any reason to start the task from the main thread the if would be in the block.)
By not initiating the next search until after you've processed the results of the first you avoid having to deal with any issues of a subsequent callback trying to update your data at the same time as a previous one.
However if you find delaying the second search in this way is too slow you can investigate ways to overlap the operations, e.g. you might have the callback just pass the processing of the results to an async task on a serial queue (so that only one set of results is being processed at once) and initiate the next async URL task.
HTH
Declare a bool variable as isLoading and if that function is loading dont trigger urlsession. hope below sample will help you.
var isLoading : Bool = false
func loadMore(with pageCount: Int){
if isLoading { return }
isLoading = true
// call the network
URLSession.shared.dataTask(with: URL(string: "xxxxx")!) { (data, response, error) in
// after updating the data set isloding to false again
// do the api logic here
//
DispatchQueue.main.async {
// self.items = downloadedItems
self.tableView.reloadData()
self.isLoading = false
}
}.resume()
}
I am trying to parse a oData web service using SwiftyJSON
Here is my oData response:
{
"odata.metadata":"http://url.com/odata/$metadata#Updates","value":[
{
"ID":1,"msgTitle":"Testing","reportedBy":"testUser"
}
]
}
Here is my Swift code:
Alamofire.request(URL, method: .get).responseString { (responseData) -> Void in
if((responseData.result.value) != nil) {
self.activityIndicator.stopAnimating()
let swiftyJsonVar = JSON(responseData.result.value!)
print(swiftyJsonVar)
if let resData = swiftyJsonVar["value"].arrayObject {
if let dict = resData as? [Dictionary<String, AnyObject>] {
for obj in dict {
let announce = announcement(fileDict: obj)
self.Announcements.append(announce)
}
self.tableView.reloadData()
self.tableView.isHidden = false
}
}
}
}
The problem is that resData is returning null. What I am doing wrong to get the JSON within the value array?
I have also tried swiftyJsonVar[0]["value"].arrayObject without success.
After consulting the swiftyJSON documentation, I was able to figure this out using the following syntax:
Alamofire.request(URL, method: .get).responseString { (responseData) -> Void in
if((responseData.result.value) != nil) {
self.activityIndicator.stopAnimating()
//log.info("Response: \(responseData.result.value)")
let jsonObj = responseData.result.value!
if let dataFromString = jsonObj.data(using: .utf8, allowLossyConversion: false) {
let json = JSON(data: dataFromString)
print(json)
if let resData = json["value"].arrayObject {
if let dict = resData as? [Dictionary<String, AnyObject>] {
for obj in dict {
let announce = announcement(fileDict: obj)
self.Announcements.append(announce)
}
self.tableView.reloadData()
self.tableView.isHidden = false
}
}
}
}
}
This question already has answers here:
Run code only after asynchronous function finishes executing
(2 answers)
Closed 5 years ago.
Im trying to wait for the function to process in order to show my image. I have try many things but none of this worked. I know this is an async function and basically i have to wait in order to get the right values but I dont know how to fix this function right here. I hope you can help me out. Thank you!
func createListProductsGood(Finished() -> void) {
refProducts.child("Products").queryOrderedByKey().observe(.childAdded, with: { snapshot in
let prod = snapshot.value as! NSDictionary
let active = snapshot.key
let rejected = prod["NotInterested"] as! String
let photoURL = prod["photoURL"] as! String
var findit = false
// print(rejected)
if (rejected != self.userUID){
//print(active)
if rejected.contains(","){
var pointsArr = rejected.components(separatedBy: ",")
for x in pointsArr{
if x.trimmingCharacters(in: NSCharacterSet.whitespaces) == self.userUID {
// print("dont show")
findit = true
return
}
}
if (findit == false){
if let url = NSURL(string: photoURL) {
if let data = NSData(contentsOf: url as URL) {
self.ProductId = active
self.productPhoto.image = UIImage(data: data as Data)
}}
}
}else{
print(active)
if let url = NSURL(string: photoURL) {
if let data = NSData(contentsOf: url as URL) {
self.ProductId = active
self.productPhoto.image = UIImage(data: data as Data)
}}
}
}
})
finished()
}
Edited:
This is how my viewDidLoad looks like:
override func viewDidLoad() {
super.viewDidLoad()
setAcceptedOrRejected()
createListProductsGood{_ in
}
}
func createListProductsGood(finished: #escaping (_ imageData: Data) -> Void) {
refProducts.child("Products").queryOrderedByKey().observe(.childAdded, with: { snapshot in
let prod = snapshot.value as! NSDictionary
let active = snapshot.key
let rejected = prod["NotInterested"] as! String
let photoURL = prod["photoURL"] as! String
var findit = false
// print(rejected)
if (rejected != self.userUID){
//print(active)
if rejected.contains(","){
var pointsArr = rejected.components(separatedBy: ",")
for x in pointsArr{
if x.trimmingCharacters(in: NSCharacterSet.whitespaces) == self.userUID {
// print("dont show")
findit = true
return
}
}
if (findit == false){
if let url = NSURL(string: photoURL) {
if let data = NSData(contentsOf: url as URL) {
self.ProductId = active
DispatchQueue.main.async {
self.productPhoto.image = UIImage(data: data as Data)
}
}}
}
}else{
print(active)
if let url = NSURL(string: photoURL) {
if let data = NSData(contentsOf: url as URL) {
self.ProductId = active
DispatchQueue.main.async {
self.productPhoto.image = UIImage(data: data as Data)
}
}}
}
}
})
}
This is my second method:
func setAcceptedOrRejected() {
refProducts.child("Products").queryOrderedByKey().observe(.childAdded, with: { snapshot in
let prod = snapshot.value as! NSDictionary
if self.ProductId == snapshot.key{
self.texto = prod["NotInterested"] as! String
self.refProducts.child("Products").child(self.ProductId).updateChildValues(["NotInterested": self.texto + ", " + self.userUID])
} })
}
You should change:
func createListProductsGood(Finished() -> void) {
to:
func createListProductsGood(finished: #escaping (_ something: SomeType) -> Void) {
or to be more specific:
func createListProductsGood(finished: #escaping (_ imageData: Data) -> Void) {
then wherever in your function you get the image, you call
finished(imageData)
so you can pass the imageData through a closure to where its needed.
then you call this function like this:
createListProductsGood{ imageData in
...
let image = UIImage(data: imageData)
// update UI from main Thread:
DispatchQueue.main.async {
self.productPhoto.image = image
}
}
Also:
it's not convention to use Finished(), you should use finished()
using void is wrong. You must use Void or ()
If you're having problems with closures and completionHandlers, I recommend you first try getting your hands dirty with a simple UIAlertController. See here. Try creating an action with a closure, e.g. see here
EDIT :
Thanks to Leo's comments:
func createListProductsGood(finished: #escaping(_ imageData: Data?, MyError?) -> Void) {
let value: Data?
let error = MyError.someError("The error message")
refProducts.child("Products").queryOrderedByKey().observe(.childAdded, with: { snapshot in
let prod = snapshot.value as! NSDictionary
let active = snapshot.key
let rejected = prod["NotInterested"] as! String
let photoURL = prod["photoURL"] as! String
var findit = false
// print(rejected)
if (rejected != self.userUID){
//print(active)
if rejected.contains(","){
var pointsArr = rejected.components(separatedBy: ",")
for x in pointsArr{
if x.trimmingCharacters(in: NSCharacterSet.whitespaces) == self.userUID {
// print("dont show")
findit = true
return
}
}
if (findit == false){
if let url = NSURL(string: photoURL) {
if let data = NSData(contentsOf: url as URL) {
self.ProductId = active // REMOVE
self.productPhoto.image = UIImage(data: data as Data) // REMOVE
finished(data, nil) //ADD
}else{
finished(nil,error) //ADD
}
}
}
}else{
print(active)
if let url = NSURL(string: photoURL) {
if let data = NSData(contentsOf: url as URL) {
self.ProductId = active // REMOVE
self.productPhoto.image = UIImage(data: data as Data) // REMOVE
finished(data,nil) //ADD
}else{
finished(nil,error) //ADD
}
}
}
}
})
}
And then you call it like:
createListProductsGood { imageData, error in guard let value = imageData, error == nil else { // present an alert and pass the error message return }
...
let image = UIImage(data: imageData)
// update UI from main Thread:
DispatchQueue.main.async {
self.ProductId = active
self.productPhoto.image = image } }
Basically this way the createListProductsGood takes in 2 closures, one for if the image is present, another for if an error was returned.
Within my user object I added a column to add a users favorite team. The column is identified as favTeam and is a pointer to a teams class
Here is my code. I have populated my user with a favorite team however the logic is always showing that "favteam nil"
if let object = PFUser.currentUser()!["favTeam"] as? [PFObject]{
print("favteam not nil")
print(object)
let favTeam = PFUser.currentUser()!["favTeam"]
favTeamText.text = favTeam["Name"] as? String
if let favTeamImageView = favTeam["teamLogo"] as? PFFile {
favTeamImageView.getDataInBackgroundWithBlock { (imageData: NSData?, error: NSError?) -> Void in
if error == nil {
if let imageData = imageData {
self.teamLogo.image = UIImage(data: imageData)
}
}
}
}
}
else {
print("favteam nil")
}
I can accomplish this by using a PFUser.query() as follows...
func fetchFavoriteTeam() {
let userQuery: PFQuery = PFUser.query()!
userQuery.whereKey("username", equalTo: (currentUser?.username)!)
userQuery.findObjectsInBackgroundWithBlock({
(users, error) -> Void in
var favTeam = users!
if error == nil {
if favTeam != nil {
favTeamContainer = favTeam.valueForKey("favTeam") as! PFObject
}
} else {
print(error)
}
})
}