I'm trying to parse a JSON with the below code and show it in a table view, but this code runs without any problems or errors, but I'm unable to make it show when I run the app in the sim or even see the JSON results in the debug window.
I'm not using Storyboard. Only working on Swift code. For this I have added the following in the AppDelegate.swift
window = UIWindow(frame: UIScreen.main.bounds)
window?.makeKeyAndVisible()
import UIKit
class Post: NSObject {
var id: String?
var title: String?
var year: NSNumber?
var quote: String?
var image: String?
var currency: NSNumber?
var desc: String?
var type: String?
}
class FeedController: UITableViewController {
var posts = [Post]()
var numberOfRows = 0
override func viewDidLoad() {
super.viewDidLoad()
if let path = Bundle.main.path(forResource: "jsonFile", ofType: "json") {
do {
let data = try NSData(contentsOfFile: path, options: NSData.ReadingOptions.mappedIfSafe)
let jsonDictionary = try JSONSerialization.jsonObject(with: data as Data, options: .mutableContainers) as! [String: AnyObject]
if let postDictionary = jsonDictionary["post"] as? [String: Any] {
let post = Post()
post.setValuesForKeys(postDictionary)
print(post.mvs_id, post.mvs_plot)
numberOfRows = (jsonDictionary["data"]?.count)!
}
print(jsonDictionary)
} catch let err {
print(err)
}
}
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return numberOfRows
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
return cell
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
I need help to understand what am I doing wrong to make this parsed JSON show when I run the app, or at least show me the results in the debugger? Thanks
Related
I am trying to populate a table with json content. Everything seems to work fine except that the table is not showing any data. Actually, the code shown below should display the "title" information of each json data array into one cell. See line
cell.textLabel?.text = myNewsItems[indexPath.row].title
However, from what I can see in the console output, I can verify that the news array is parsed like expected (see Checkpoint: print(myNewsS)).
Any idea what I am missing?
Swift4
import UIKit
// structure from json file
struct News: Codable{
let type: String
let timestamp: String
let title: String
let message: String
}
class HomeVC: UIViewController, UITableViewDelegate, UITableViewDataSource{
var myTableView = UITableView()
var myNewsItems: [News] = []
override func viewDidLoad() {
super.viewDidLoad()
let barHeight: CGFloat = UIApplication.shared.statusBarFrame.size.height
let displayWidth: CGFloat = self.view.frame.width
let displayHeight: CGFloat = self.view.frame.height
myTableView = UITableView(frame: CGRect(x: 0, y: 150, width: displayWidth, height: displayHeight - barHeight))
myTableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
myTableView.dataSource = self
myTableView.delegate = self
self.view.addSubview(myTableView)
// JSON
let url=URL(string:"https://api.myjson.com/bins/ywv0k")
let session = URLSession.shared
let task = session.dataTask(with: url!) { (data, response, error) in
// check status 200 OK etc.
guard let data = data else { return }
do {
let myNewsS = try
JSONDecoder().decode([News].self, from: data)
print(myNewsS)
DispatchQueue.main.async {
self.myTableView.reloadData()
}
} catch let jsonErr {
print("Error json:", jsonErr)
}
}
task.resume()
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return myNewsItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = myNewsItems[indexPath.row].title
return cell
}
}
Assign the array
myNewsItems = myNewsS
DispatchQueue.main.async {
self.myTableView.reloadData()
}
Guys i want to get all names from JSON (screenshot below) and put them to tableView. The problem is...i got dictionary with this code. Now, how i can get each name value and put them on tableView.
func getDataFromApi(){
Alamofire.request("https://api.coinmarketcap.com/v2/listings/").responseJSON{ response in
if let locationJSON = response.result.value{
let locationObject: Dictionary = locationJSON as! Dictionary<String, Any>
for (key, value) in locationObject {
print("id:\(key), value:\(value)")
}
}
}
}
I would suggest convert the dictionaries response to a Currency object:
class Currency: NSObject {
var id: Int!
var name: String!
var symbol: String!
var websiteSlug: String!
init(id: Int, name: String, symbol: String, websiteSlug: String) {
super.init()
self.id = id
self.name = name
self.symbol = symbol
self.websiteSlug = websiteSlug
}
}
Then under the variables' section define the currencies array:
var currencies = [Currency]()
Finaly change the getDataFromApi implementation to this:
func getDataFromApi() {
Alamofire.request("https://api.coinmarketcap.com/v2/listings/").responseJSON{ response in
if let locationJSON = response.result.value as? [String: Any] {
let data = locationJSON["data"] as! [[String: Any]]
for dataItem in data {
let currency = Currency(id: dataItem["id"] as! Int,
name: dataItem["name"] as! String,
symbol: dataItem["symbol"] as! String,
websiteSlug: dataItem["website_slug"] as! String)
self.currencies.append(currency)
}
print(self.currencies)
}
}
}
I always suggest model the responses to objects because it allows you to do a better managing of the data you need to display on screen and keep your code structure organised.
Now you can easily show the data in a UITableView object from the currencies array.
I would suggest convert the Array In dictionaries response un a Currency object:
var dataArray = NSArray()
#IBOutlet var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a
nib.
self.getDataFromApi()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func getDataFromApi(){
Alamofire.request("https://api.coinmarketcap.com/v2/listings/").responseJSON{ response in
if let locationJSON = response.result.value{
let locationObject: Dictionary = locationJSON as! Dictionary<String, Any>
self.dataArray = locationObject["data"]as! NSArray
self.tableView.reloadData()
// for (key, value) in locationObject {
// print("id:\(key), value:\(value)")
// }
}
}
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return dataArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier:"cell") as! UITableViewCell
cell.textLabel?.text = (dataArray.object(at:indexPath.row) as! NSDictionary).value(forKey:"name") as! String
cell.detailTextLabel?.text = (dataArray.object(at:indexPath.row) as! NSDictionary).value(forKey:"symbol") as! String
return cell
}
var nameArray = [String]()
override func viewDidLoad() {
super.viewDidLoad()
getData()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return nameArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! tableCell
cell.nameLabel.text = nameArray[indexPath.row]
return cell
}
func alamofire() {
Alamofire.request("https://api.coinmarketcap.com/v2/listings/", method: .get, parameters: nil, encoding: URLEncoding.default, headers: nil).responseJSON { (response:DataResponse<Any>) in
switch(response.result) {
case .success(_):
guard let json = response.result.value as! [String:Any] else{ return}
guard let data = ["data"] as! [[String: Any]] else { return}
for item in data {
if let name = item["name"] as? String {
self.nameArray.append(name)
}
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
break
case .failure(_):
print(response.result.error as Any)
break
}
}
}
Here i have created table view with labelName and labelUsername,
and i have downloaded Json data and saving it in core data entity called Details which contains attributes name and username..
here table view showing its data in online...
but how can i show fetched data in table view while in offline..
please help me in the code...
import UIKit
import CoreData
struct JsonData {
var nameS: String
var usernameS: String
init(name: String, username: String) {
self.nameS = name
self.usernameS = username
}
}
class ViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
var iteamsArray = [JsonData]()
override func viewDidLoad() {
downloadJson()
}
func downloadJson(){
let urlStr = "https://jsonplaceholder.typicode.com/users"
let url = URL(string: urlStr)
URLSession.shared.dataTask(with: url!, completionHandler: {(data, response, error) in
guard let respData = data else {
return
}
guard error == nil else {
print("error")
return
}
do{
let jsonObj = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [[String: Any]]
for items in jsonObj {
let nameJson = items["name"] as? String
let usernameJson = items["username"] as? String
let coreData = NSEntityDescription.insertNewObject(forEntityName: "Details", into: self.context) as! Details
coreData.name = nameJson
coreData.username = usernameJson
self.iteamsArray.append(JsonData(name: nameJson!, username: usernameJson!))
}
try self.context.save()
//fetching from core data
let fetchRequest : NSFetchRequest<Details> = Details.fetchRequest()
let details = try self.context.fetch(fetchRequest)
if details.count > 0 {
for detail in details as [NSManagedObject] {
let nameCore = detail.value(forKey: "name")
let usernameCore = detail.value(forKey: "username")
}
}
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
catch {
print("catch error")
}
}).resume()
}
}
// MARK: - TableView
extension ViewController: UITableViewDataSource, UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return iteamsArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "JsonCell", for: indexPath) as! JsonTableViewCell
let aData = iteamsArray[indexPath.row]
cell.labelName.text = aData.nameS
cell.labelUsername.text = aData.usernameS
cell.selectionStyle = .none
return cell
}
}
First of all forget the custom struct. Use the NSManagedObject class as data source array.
var iteamsArray = [Details]()
In viewDidLoad first fetch the data, if the array is empty load it from the web service
override func viewDidLoad() {
let fetchRequest : NSFetchRequest<Details> = Details.fetchRequest()
do {
iteamsArray = try self.context.fetch(fetchRequest)
if iteamsArray.isEmpty {
downloadJson()
} else {
self.tableView.reloadData()
}
} catch { print(error) }
}
In downloadJson() replace
self.iteamsArray.append(JsonData(name: nameJson!, username: usernameJson!))
with
self.iteamsArray.append(coreData)
and remove these lines
//fetching from core data
let fetchRequest : NSFetchRequest<Details> = Details.fetchRequest()
let details = try self.context.fetch(fetchRequest)
if details.count > 0 {
for detail in details as [NSManagedObject] {
let nameCore = detail.value(forKey: "name")
let usernameCore = detail.value(forKey: "username")
}
}
In cellForRow get the values directly from the NSManagedObject objects
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "JsonCell", for: indexPath) as! JsonTableViewCell
let aData = iteamsArray[indexPath.row]
cell.labelName.text = aData.name
cell.labelUsername.text = aData.userName
cell.selectionStyle = .none
return cell
}
I have parsed a json string and i want to use it in a tableview. when i try to append the json string into an array the append method is not working. Here is the code that i have used. Can anyone help me with this?
import UIKit
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var tableView: UITableView!
var userName = [String]()
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
// 1
let urlAsString = "http://demo.codeofaninja.com/tutorials/json-example-with-php/index.php"
let url = NSURL(string: urlAsString)!
let urlSession = NSURLSession.sharedSession()
//2
let jsonQuery = urlSession.dataTaskWithURL(url, completionHandler: { data, response, error -> Void in
if (error != nil) {
print(error!.localizedDescription)
}
// 3
do {
let jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary
/*let err: NSError!
if (err != nil) {
print("JSON Error \(err.localizedDescription)")
}*/
// 4
//let fname: String! = jsonResult["firstname"] as! String
//let lname: String! = jsonResult["lastname"] as! String
//let usrname: String! = jsonResult["username"] as! String
dispatch_async(dispatch_get_main_queue(), {
if let users = jsonResult.objectForKey("Users") as? [[String:AnyObject]]
{
for user in users
{
print("First Name:")
print(user["firstname"]!)
print("Last Name:")
print(user["lastname"]!)
print("User Name:")
let nameUser = user["username"]! as! String
print(nameUser)
self.userName.append(nameUser)
print("***************")
}
}
//print(jsonResult["Users"]!)
//print(lname)
//print(usrname)
})
}
catch {
print("error");
}
})
jsonQuery.resume()
//self.userName.append("ganesh")
// 5
print(userName)
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return userName.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell") as UITableViewCell!
cell.textLabel?.text = userName[indexPath.row]
return cell
}
func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
userName.removeAtIndex(indexPath.row)
tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Automatic)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
You are appending right in the array,Just call self.tableView.reloadData() to refresh table view at the end of dispatch to show the data in the tableView.
The append function works fine but you are filling the array in the background and never reloading the tableView when you have the data in the array
for user in users
{
if let nameUser = user["username"] as? String {
self.userName.append(nameUser)
}
}
self.tableView.reloadData()
Try this inside the if let users = jsonResult.objectForKey("Users") as? [[String:AnyObject]] block
I have seen someone create an object to receive the JSON data, then have an array of that object. and upon receiving new data from the JSON the Object array updates and the table view reloads.
How would i do this? I didn't really understand it, but i now need it as i need to receive data from PHP then parse it in Xcode onto a table view.
If you could, i would really be grateful if you could also show any optimisation tips.
I think they used the didSet variable in their code.
Thank you for reading!
This is what you meant with didSet right?
class ViewController: UIViewController, UITableViewDataSource {
#IBOutlet weak var myTableView: UITableView!
private var dataArray: [String] = [String]() {
didSet {
myTableView.reloadData()
}
}
override func viewDidLoad() {
super.viewDidLoad()
let jsonRequest: NSURLRequest = NSURLRequest(URL: NSURL(string: "yourEndPoint")!)
NSURLConnection.sendAsynchronousRequest(jsonRequest, queue: NSOperationQueue.mainQueue()) { (response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in
if let jsonArray: [[String: String]] = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableLeaves, error: nil) as? [[String: String]] {
for jsonObject in jsonArray {
if let stringFromKey: String = jsonObject["yourKey"] as String? {
self.dataArray.append(stringFromKey)
}
}
}
}
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return dataArray.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
cell.textLabel?.text = dataArray[indexPath.row]
return cell
}
}
You just need to exchange the JSON Parsing and Array type to fit your purpose