I am new to swift and in programming, and I am trying to parse a JSON with the help of Alamofire and SwiftyJSON, if the JSON file is simple, I have no problems and working good, but when I have something like Dictionary -> Dictionary -> Array -> Dictionary, problems begin, so I have the following code:
func performCYesterdayWeatherFetch(forSelectedCity: String)
{
let properString = forSelectedCity.addingPercentEncoding(withAllowedCharacters:NSCharacterSet.urlQueryAllowed)
Alamofire.request("http://api.apixu.com/v1/history.json?key=MY_KEY&q=\(properString!)&dt=2016-10-20").responseJSON { (response) -> Void in
guard response.result.isSuccess else
{
print("Error while fetching remote rooms: \(response.result.error)")
return
}
guard let json = response.result.value as? JSON,
let forecastJson = json["forecast"].dictionary else
{
print("YESTERDAY PROBLEM")
return
}
for item in (forecastJson["forecastday"]?.arrayValue)!
{
let day = item["day"].dictionaryObject
guard let yesterdayTempCels = day?["avgtemp_c"] as! Double?,
let yesterdayTempFahr = day?["avgtemp_f"] as! Double? else
{
return
}
MY_KEY - is really my key, the problem is not in that i didn't input the key.
It always get in else here:
guard let json = response.result.value as? JSON,
let forecastJson = json["forecast"].dictionary else
{
print("YESTERDAY PROBLEM")
return
}
They result JSON looks like that:
The thin I need is avgtemp_c and avgtemp_f
What am I doing wrong?
Here you have a solution where you don't even need SwiftyJSON to get those values.
let properString = forSelectedCity.addingPercentEncoding(withAllowedCharacters:NSCharacterSet.urlQueryAllowed)
Alamofire.request("http://api.apixu.com/v1/history.json?key=MY_KEY&q=\(properString!)&dt=2016-10-20").responseJSON { (response) -> Void
guard let json = response.result.value as? [String: Any],
let forecastDictionary = json["forecast"] as? [String: Any],
let forecastDayArray = forecastDictionary["forecastday"] as? [[String: Any]] else {
print("YESTERDAY PROBLEM")
return
}
for item in forecastDayArray {
guard let day = item["day"] as? [String: Any],
let yesterdayTempCels = day["avgtemp_c"] as? Double,
let yesterdayTempFahr = day["avgtemp_f"] as? Double else {
return
}
// Here you should have the values that you need
}
}
Related
I need to fetch some quizzes for my application from the server. Unfortunately, it seems that URLSession.DataTask.shared is not working. How do I fix the problem?
This is for Swift 4.
import Foundation
import UIKit
class QuizService {
let baseUrl = "https://iosquiz.herokuapp.com/api/quizzes"
func fetchQuizzes(completion: #escaping (([Quiz]?) -> Void)) -> Void {
if let url = URL(string: baseUrl) {
let request = URLRequest(url: url)
let dataTask = URLSession.shared.dataTask(with: request) { (data, response, error) in
if let data = data {
do {
let json = try JSONSerialization.jsonObject(with: data, options: [])
if let resultsList = json as? [String: Any], let results = resultsList["quizzes"] as? [[String: Any]] {
let quizzes = results.map({ json -> Quiz? in
print(json)
if
let title = json["title"] as? String,
let id = json["id"] as? Int,
let level = json["level"] as? Int,
let description = json["description"] as? String,
let category = json["category"] as? String,
let questions = json["questions"] as? [String: Any],
let imageUrl = json["image"] as? String {
let quiz=Quiz(id:id,title:title,descript:description,category:category,level:level,imageUrl:imageUrl,questions:questions)
return quiz
} else {
return nil
}
}).filter { $0 != nil } .map { $0! }
completion(quizzes)
} else {
completion(nil)
}
} catch {
completion(nil)
}
} else {
completion(nil)
}
}
dataTask.resume()
} else {
completion(nil)
}
}
}
My error is that field of quizzes are null, so my code is not working in my view controller.
I took a look at the response here https://iosquiz.herokuapp.com/api/quizzes.
The "questions" should be array of dictionaries instead of dictionary.
so it should works if you replace this line
let questions = json["questions"] as? [String: Any]
with this line
let questions = json["questions"] as? [[String: Any]]
BTW, I prefer to extract the logic of parsing json into another method to keep fetchQuizzes method simple.
Hope this helps!
I'm trying to get data from an API with no documentation.
My code is
let URL_MAIN = "http://evarsity.srmuniv.ac.in/srmswi/usermanager/youLogin.jsp"
let URL_ATTENDANCE = "http://evarsity.srmuniv.ac.in/srmswi/resource/StudentDetailsResources.jsp?resourceid=7"
let URL_TIMETABLE = "http://evarsity.srmuniv.ac.in/srmswi/resource/StudentDetailsResources.jsp?resourceid=5"
func getData(url: String) {
Alamofire.request(url, method: .get)
.responseData { response in
if response.result.isSuccess {
print("Sucess! Got the data")
guard let data = response.result.value else { return }
print(data)
} else {
print("Error: \(String(describing: response.result.error))")
}
}
I am getting the response as 51406 bytes.
I need to get the actual data in either JSON or some other format. Here is the api link for python
https://github.com/arjunmahishi/srm-erp-api/blob/master/erp.py
Convert your responseData to a dictionary using the function i provided below and then parse the data accordingly.Here, i m getting a JSON response in the form of a dictionary.
let strResponse = "\(responseString.value!)"
let arr = strResponse.components(separatedBy: "\n")
let dict = convertStringToDictionary(str:(arr.last ?? "")!)
self.Message = dict?["message"] as! String
let responseStatus = dict?["status"] as! NSString
public func convertStringToDictionary(str:String) -> [String: Any]? {
if let data = str.data(using: .utf8) {
do {
return try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any]
} catch {
print(error.localizedDescription)
}
}
return nil
}
I'm trying to pass data from a JSON response to a table view cell. I'm having problems with capturing the response values that I'm extracting in URLSession.shared.dataTask.
func callYouTubeAPIToGetAllVideos() {
let url = URL(string: "https://www.googleapis.com/youtube/v3/search?part=snippet&channelId=XYZ&maxResults=50&order=date&key=ABC")
let task = URLSession.shared.dataTask(with: url!) { (data, response, error) in
if error != nil {
print(error!)
} else {
if let usableData = data {
let json = try? JSONSerialization.jsonObject(with: usableData, options: [])
if let dictionary = json as? [String: Any?] {
if let array = dictionary["items"] as? [Any] {
for object in array {
if let objectAsDictionary = object as? [String: Any?] {
if let objectWithKindAndVideoId = objectAsDictionary["id"] as? [String: String] {
if let videoId = objectWithKindAndVideoId["videoId"] {
//pass data to table cell
}
}
if let snippet = objectAsDictionary["snippet"] as? [String: Any] {
if let description = snippet["description"] {
//pass data to table cell
}
}
}
}
}
}
}
}
}
task.resume()
}
I tried appending the values to an instance variable but it didn't work.
Sorry about the messy code, this is my 1st time working with JSON in Swift.
First of all never declare a received JSON dictionary as [String:Any?]. A received dictionary value can't be nil.
Declare a custom struct Video.
struct Video {
let videoId : String
let description : String
}
Declare a data source array.
var videos = [Video]()
Parse the JSON into the array and reload the table view on the main thread.
func callYouTubeAPIToGetAllVideos() {
let url = URL(string: "https://www.googleapis.com/youtube/v3/search?part=snippet&channelId=XYZ&maxResults=50&order=date&key=ABC")
let task = URLSession.shared.dataTask(with: url!) { (data, response, error) in
if error != nil {
print(error!)
} else {
do {
if let dictionary = try JSONSerialization.jsonObject(with: data!) as? [String: Any],
let array = dictionary["items"] as? [[String: Any]] {
for object in array {
if let objectWithKindAndVideoId = object["id"] as? [String: String],
let snippet = object["snippet"] as? [String: Any] {
let videoId = objectWithKindAndVideoId["videoId"] ?? ""
let description = snippet["description"] as? String ?? ""
let video = Video(videoId: videoId, description: description)
self.videos.append(video)
}
}
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
} catch {
print(error)
}
}
}
task.resume()
}
In cellForRow assign the values to the text properties
let video = videos[indexPath.row]
cell.textLabel!.text = video.videoId
cell.detailTextLabel?.text = video.description
I'm having a problem with the following code. I'm downloading a list of actors in JSON and I want to populate Struct Actor with the received data. Everything works great until I try to flatMap on the received data and try to initialize the struct Actor. When I try to compile the code i get the error: Cannot assign value of type '()' to type [Actor]. The error corresponds to a line in viewDidLoad actorsList = downloadActors() Would anybody have any recommendation who to solve this?
import UIKit
func downloadActors() {
var request = URLRequest(url: URL(string: "url...")!)
request.httpMethod = "POST"
let postString = "actorGroup=\("Superhero")"
request.httpBody = postString.data(using: .utf8)
let task = URLSession.shared.dataTask(with: request) { data, response, error in
DispatchQueue.main.async {
guard let data = data, error == nil else {
print("error=\(error)")
return
}
if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode != 200 {
print("error : statusCode should be 200 but is \(httpStatus.statusCode)")
print("response = \(response)")
}
if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode == 200 {
do {
let json = try JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.mutableContainers) as? [String: AnyObject]
guard let actorsJSON = json?["response"] as? [[String : AnyObject]] else {
return
}
} catch {
print("catch error")
}
}
}
}
task.resume()
}
func loadActors() -> [Actor] {
if let actors = actorsJSON as? [[String : AnyObject]] {
return actors.flatMap(Actor.init)
}
}
let actorsArray = loadActors()
class MasterViewController: UITableViewController {
var actorsList = [Actor]()
var detailViewController: DetailViewController? = nil
var objects = [Any]()
override func viewDidLoad() {
super.viewDidLoad()
actorsList = downloadActors()
print(actorsList)
Struct Actors is as follows:
struct Job {
let actorGroup: String
let actorName: String
}
extension Actor: JSONDecodable {
init?(JSON: [String : AnyObject]) {
guard let actorGroup = JSON["actorGroup"] as? String, let actorName = JSON["actorName"] as? String else {
return nil
}
self. actorGroup = actorGroup
self. actorName = actorName
}
}
let listActors = actorsJSON as? [[String : AnyObject]] {
Should be:
if let listActors = actorsJSON as? [[String : AnyObject]] {
Edit: For more info I'd like to add Vadian's comment:
Very confusing code. What does the function in the middle of the do block? Why do you type-check actorsJSON twice? The computed property is let listActors... which should be probably an optional binding (if let ... ). Further .mutableContainers is completely nonsense in Swift. And finally a JSON dictionary is [String:Any] in Swift 3.
I'm coming from android programming to Swift iOS programming and have a hard time parsing a json
here's String I try to parse :
{"response":[{"uid":111,"first_name":"someName","last_name":"someLastName","photo_100":"http:someUrl/face.jpg"}]}
here how I try to parse this :
if let dict = Utils.convertStringToDictionary(response)! as? [String: AnyObject]{
// this part is yet doing ok
if let response = dict["response"] as? [String: AnyObject]{
NSLog("let response \(response)")
if let first_name = response["first_name"] as? String {
NSLog("first_name = \(first_name)")
}
}
else {
NSLog("not an []")
}
the Log message gives me "not an []" as it can't make a response object. As far as I understand, I'm doing right as [String: AnyObject] is what is in "response" body of my json
Just in case, here's my Utils.convertStringToDictionary method:
public static func convertStringToDictionary(text: String) -> [String:AnyObject]? {
if let data = text.dataUsingEncoding(NSUTF8StringEncoding) {
do {
let json = try NSJSONSerialization.JSONObjectWithData(data, options: .MutableContainers) as? [String:AnyObject]
return json
} catch {
NSLog("Something went wrong")
}
}
return nil
}
Array in swift denotes with []
Dictionary in swift denotes with [:]
your response parameter is array of dictionary ... so it denotes with [[:]]
so just parse it with [[String: AnyObject]]
if let response = dict["response"] as? [[String: AnyObject]]{
for user in response{
NSLog("let response \(user)")
if let first_name = user["first_name"] as? String {
NSLog("first_name = \(first_name)")
}
}
}
Problem here is response is an array
if let response = dict["response"] as? NSArray{
for value in response as? NSDictionary{
print(value["uid"]) /// prints 111
print(value["first_name"]) /// prints someName
}
}
Try this code
if let dict = Utils.convertStringToDictionary(response)! as? [String: AnyObject]{
// this part is yet doing ok
if let response = dict["response"] as? NSArray{
NSLog("let response \(response)")
for dict in response{
if let first_name = dict["first_name"] as? String {
NSLog("first_name = \(first_name)")
}
}
}
else{
NSLog("not an []")
}
}