I'm currently learning API by doing a project that shows list of games from rawg.io referring to the website's doc.
To call the data from it, i created struct and defining keys in GameFeed.swift & GameDetail.swift
GameFeed.swift :
import Foundation
struct GameFeed: Codable {
var results:[GameDetail]
}
GameDetail.swift :
import Foundation
struct GameDetail: Codable {
var id:String?
var name:String?
var rating:String?
}
I also defining URLString with URL Link & JSONDecoder() in ViewController.swift
let urlString = "https://api.rawg.io/api/games"
let url = URL(string: urlString)
guard url != nil else {
return
}
let session = URLSession.shared
let dataTask = session.dataTask(with: url!){
(data, response, error) in
if error == nil && data != nil {
let decoder = JSONDecoder()
do {
let gameFeed = try decoder.decode(GameFeed.self, from: data!)
print(gameFeed)
}
catch {
print("Error Parsing JSON")
}
}
}
dataTask.resume()
}
When i launch it, i think the data is successfully pulled from website as it shown here
but the end result is "Error Parsing JSON"
How can i make it possible to retrieve the data and show it to console?
The problem is that you defined the id and the rating fields as strings, while in the JSON response, they are Int and Double, respectively.
You should change GameDetail.swift so it looks like this:
struct GameDetail: Codable {
var id:Int?
var name:String?
var rating:Double?
}
Related
There are two kinds of URLs
http://www.mocky.io/v2/5e91af4b3300008300e9cfd1 (this is which I made)
http://183.111.148.229/mob_json/mob_json.aspx?nm_sp=UP_MOB_CHECK_LOGIN¶m=1000|1000|1 (I need to get data from this URL)
Only number1. URL returns JSON data even if they have same structure. I couldn't find way to resolve this problem.
this is my network manager code
import Foundation
class NetworkManager: ObservableObject {
#Published var posts = [Post]()
func fetchData() {
if let url = URL(string: "http://www.mocky.io/v2/5e91af4b3300008300e9cfd1") {
let session = URLSession(configuration: .default)
let task = session.dataTask(with: url) { (data, response, error) in
if error == nil {
let decoder = JSONDecoder()
if let safeData = data {
do {
let results = try decoder.decode(Results.self, from: safeData)
DispatchQueue.main.async {
self.posts = results.Table
}
} catch {
print(error)
}
}
}
}
task.resume()
}
}
}
and my post data model
import Foundation
struct Results: Decodable {
let Table: [Post]
}
struct Post: Decodable, Identifiable {
var id: String {
return CD_FIRM
}
let CD_FIRM: String
let NM_FIRM: String
let CD_USER: String
let NM_USER: String
}
Can anyone can help me for this problem?
I want to get JSON data from URL number 2.
please help me =)
It looks like the issue with your second url is the pipes | at the end. One way to avoid this issue is to use URLComponents
So insert this at the start of fetchData
var urlComponents = URLComponents()
urlComponents.scheme = "http"
urlComponents.host = "183.111.148.229"
urlComponents.path = "/mob_json/mob_json.aspx"
urlComponents.queryItems = [
URLQueryItem(name: "nm_sp", value: "UP_MOB_CHECK_LOGIN"),
URLQueryItem(name: "param", value: "1000|1000|1")
]
And then get the url from the components
if let url = urlComponents.url {
let session = URLSession(configuration: .default)
//... same as before
I'm new to swift language and trying to work on the API below..
https://api.foursquare.com/v2/venues/search?ll=40.7484,-73.9857&oauth_token=NPKYZ3WZ1VYMNAZ2FLX1WLECAWSMUVOQZOIDBN53F3LVZBPQ&v=20180616
I'm trying to parse the data and then serialise, however I'm not able to map the data.
struct Venue: Codable {
let id: String
let name: String
let contact: Location
}
struct Location: Codable {
let address: String
let postalCode: String
}
class DataService {
private init() {}
static let shared = DataService()
func getdata() {
guard let url = URL(string: "https://api.foursquare.com/v2/venues/search?ll=40.7484,-73.9857&oauth_token=NPKYZ3WZ1VYMNAZ2FLX1WLECAWSMUVOQZOIDBN53F3LVZBPQ&v=20180616") else { return }
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
if let data = data {
do {
guard let venues = try? JSONDecoder().decode([Venue].self, from: data) else { return }
print(venues[0].id)
} catch let jsonError {
print(jsonError)
}
}
}
task.resume()
}
}
I need to work on venues array ( mainly "id", "name", "location" ( "address", "postalCode" ))
I'm trying to use the codable and decodable, how do I get the the results, please help.
This is a very common mistake.
You ignore the root object (the dictionary containing the meta and response keys). And the venues are in the dictionary for key response, a sub-dictionary of the root object
struct Root : Decodable {
let response : Response
}
struct Response : Decodable {
let venues : [Venue]
}
struct Venue: Decodable {
let id: String
let name: String
let location : Location
}
struct Location: Decodable { // both struct members must be optional
let address: String?
let postalCode: String?
}
And – as Joakim already said in the comments – never ignore Decoding errors. Decoding errors are very descriptive. They contain the specific error message as well as the CodingPath of the error.
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
if let data = data {
do {
let result = try JSONDecoder().decode(Root.self, from: data)
result.response.venues.forEach{print($0.id)}
} catch {
print(error)
}
}
}
task.resume()
I am receiving a result from an API, I can iterate through the result. My understanding is I can pass the value into a model immediately.
Apple Developer article on struct models
My issue is I am not doing it properly and am receiving a nil value. Perhaps someone can see where I need to change. I am using Swift 4.2
Here is my struct model.
import Foundation
struct ProfileModel {
//MARK: Properties
var name: String
var email: String
var profileURL: String
//MARK: Initialization
}
extension ProfileModel{
init?(json: [String:AnyObject]) {
guard
let name = json["name"] as? String,
let email = json["email"] as? String,
let profileURL = json["profileURL"] as? String
else { return nil }
self.name = name
self.email = email
self.profileURL = profileURL
}
}
Here is my result code from my urlConnection. Let me know if we want to see the entire swift file
//create dataTask using the session object to send data to the server
let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
guard error == nil else {
return
}
guard let data = data else {
return
}
do {
//create json object from data
if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String:AnyObject] {
self.onSuccess(data: json)
}
} catch let error {
print(error.localizedDescription)
}
})
task.resume()
}
func onSuccess(data: [String:AnyObject]){
print("onSuccess")
let myProfile = ProfileModel(json: data)
//myProfile is nil while unwrapping
let title: String = myProfile!.name
print(title)
}
I could just iterate through the strings since I am able to print 'data'. I just figured it would be cleaner to put everything into a ProfileModel and manage that object as a whole.
This json is my more simple one which is why I used it for this question. I also can't remember but I had to use "[String:AnyObject]" to get the json properly. This was pulled directly from my terminal, this was the data being passed in my JsonResponse. The output json from Xcode has [] on the outside instead.
{
'detail': 'VALID',
‘name’: ‘Carson,
'email': ‘carson.skjerdal#somethingelselabs.com',
'pic_url': None
}
EDIT:
So my problem is solved, and ultimately moving to Codable was the key. Here is my fixed code for anyone who might need a working solution.
URLSession.shared.dataTask(with: request as URLRequest) { (data, response
, error) in
guard let data = data else { return }
do {
let decoder = JSONDecoder()
let gitData = try decoder.decode(ProfileModel.self, from: data)
print(gitData.name)
self.onSuccess(data: gitData)
} catch let err {
print("Err", err)
}
}.resume()
}
func onSuccess(data: ProfileModel){
print("onSuccess")
print(data.email)
}
My Codable Struct - slightly simplified
import Foundation
struct ProfileModel: Codable {
let detail, name, email: String
private enum CodingKeys: String, CodingKey {
case detail, email
case name = "firstname"
//case picUrl = "pic_url"
}
}
After "Codable" has been introduced I always uses that.
You can take your JSON ans pars it in to QuickType.io, and you will get a Struct that confirms to the codadable
// To parse the JSON, add this file to your project and do:
//
// let aPIResponse = try? newJSONDecoder().decode(APIResponse.self, from: jsonData)
import Foundation
struct APIResponse: Codable {
let detail, name, email, picUrl: String
enum CodingKeys: String, CodingKey {
case detail, name, email
case picUrl = "pic_url"
}
}
I'm trying to parse JSON response using Codable but it gives me error.
I tried to refer from the below stack overflow link but did not work.
how do I parse Any in dictionary using swift
Below is my code, not sure where I'm wrong in this.
> enum JSONError: String,Error {
> case NoData = "ERROR: no data"
> case ConversionFailed = "ERROR: conversion from JSON failed"
> }
struct Owner : Decodable {
let full_name : String
let html_url:String
let follower:follower
}
struct follower : Decodable {
let followers_url : String
}
func jsonParser() {
let urlPath = "https://api.github.com/search/repositories?q=language:ruby&sort=stars&order=desc"
guard let endpoint = NSURL(string: urlPath) else {
print("Error creating endpoint")
return
}
let request = NSMutableURLRequest(url:endpoint as URL)
URLSession.shared.dataTask(with: request as URLRequest) { (data, response, error) in
do {
guard let data = data else {
throw JSONError.NoData
}
let jsonResponse = try JSONSerialization.jsonObject(with:
data)
let entries = try! JSONDecoder().decode([Owner].self, from: jsonResponse as! Data)
print(jsonResponse)
} catch let error as JSONError {
print(error.rawValue)
} catch let error as NSError {
print(error.debugDescription)
}
}.resume()
}
I need to get 3 information from this response - full name, html url and followers.
Link for web api
https://api.github.com/search/repositories?q=language:ruby
Please latest have a look at the code.
Below is the error message :
'__NSDictionaryI' (0x102965a98) to 'NSData' (0x102964580). 2019-02-09
16:17:42.062971+0530 PhotoViewwer[13342:259997] Could not cast value
of type '__NSDictionaryI' (0x102965a98) to 'NSData' (0x102964580).
Thanks
Please learn to read JSON. It's pretty easy. There are only two collection types, array ([]) and dictionary ({})
Your structs are wrong.
In the root dictionary of the JSON there is an array of dictionaries for key items.
In each dictionary there are keys full_name and owner (here is the location of the Owner struct).
A dictionary for key follower does not exist.
These structs represent the JSON correctly
struct Response : Decodable {
let items : [Item]
}
struct Item : Decodable {
let fullName : String
let owner : Owner
}
struct Owner : Decodable {
let htmlUrl : URL // URL strings can be decoded directly into URL
let followersUrl : URL
}
Add a completion handler to your function and use an enum as result type. The failure case returns all real errors. An URLRequest is redundant. Just pass the URL. The JSONSerialization line is pointless.
The convertFromSnakeCase strategy converts snake_cased keys to camelCased struct members
enum Result {
case success(Response), failure(Error)
}
func jsonParser(completion: #escaping (Result) -> Void) {
let endpoint = URL(string:"https://api.github.com/search/repositories?q=language:ruby&sort=stars&order=desc")!
URLSession.shared.dataTask(with: endpoint) { (data, response, error) in
if let error = error { completion(.failure(error)); return }
do {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let entries = try decoder.decode(Response.self, from: data!)
completion(.success(entries))
} catch {
completion(.failure(error))
}
}.resume()
}
And call it
jsonParser { result in
switch result {
case .success(let entries) : print(entries)
case .failure(let error) : print(error)
}
}
Basically never use NS... classes if there are native equivalents, here URL for NSURL and URLRequest for NS(Mutable)URLRequest
Edit:
In Swift 5 the syntax becomes more convenient using the native Result type. It is able to convert the throwing expression
enum Result {
case success(Response), failure(Error)
}
func jsonParser(completion: #escaping (Result<Response,Error>) -> Void) {
let endpoint = URL(string:"https://api.github.com/search/repositories?q=language:ruby&sort=stars&order=desc")!
URLSession.shared.dataTask(with: endpoint) { (data, response, error) in
if let error = error { completion(.failure(error)); return }
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
completion(Result{ try decoder.decode(Response.self, from: data!) })
}.resume()
}
You need
func jsonParser() {
let urlPath = "https://api.github.com/search/repositories?q=language:ruby&sort=stars&order=desc"
guard let endpoint = NSURL(string: urlPath) else {
print("Error creating endpoint")
return
}
let request = NSMutableURLRequest(url:endpoint as URL)
URLSession.shared.dataTask(with: request as URLRequest) { (data, response, error) in
do {
let dec = JSONDecoder()
dec.keyDecodingStrategy = .convertFromSnakeCase
let entries = try dec.decode(Root.self, from:data!)
print(entries)
} catch {
print(error)
}
}.resume()
}
struct Root : Decodable {
let items:[Item]
}
struct Owner: Codable {
let login: String
let id: Int
let nodeId: String
let avatarUrl: String
let gravatarId: String
let url, htmlUrl, followersUrl: String
let followingUrl, gistsUrl, starredUrl: String
let subscriptionsUrl, organizationsUrl, reposUrl: String
let eventsUrl: String
}
struct Item: Codable {
let fullName : String
let htmlUrl:String
let owner: Owner
}
You shouldn't cast the response to data here
from: jsonResponse as! Data)
as it will crash
I was trying to parse JSON through JSONDecoder and using Alamofire to fetch the data. However, when I run the app, it shows that the data couldn't be read because of the incorrect format. I have tried many things but still did not work. Any help would be appreciated. Sources are below:
VC:
class SecondTaskVC: UIViewController {
var weatherModel = [WeatherModelDecodable]()
override func viewDidLoad() {
let url = URL(string: "https://api.openweathermap.org/data/2.5/forecast?lat=42.874722&lon=74.612222&APPID=079587841f01c6b277a82c1c7788a6c3")
Alamofire.request(url!).responseJSON { (response) in
let result = response.data
do{
let decoder = JSONDecoder()
self.weatherModel = try decoder.decode([WeatherModelDecodable].self, from: result!) // it shows this line as a problem
for weather in self.weatherModel {
print(weather.city.name)
}
}catch let error{
print("error in decoding",error.localizedDescription)
}
}
}
}
Data Model:
struct WeatherModelDecodable: Decodable {
let city: CityDecodable
}
struct CityDecodable: Decodable {
let name: String
}
Actually the response structure is different from what you are trying to do at this line,
self.weatherModel = try decoder.decode([WeatherModelDecodable].self, from: result!)
The response is not an array as you can see it in a json viewer by hitting this Url in any browser. You are expecting an array of json objects but its not. So if you decode it as a single object, it will decode properly as below,
let weatherModel = try decoder.decode(WeatherModelDecodable.self, from: result!)
print(weatherModel.city.name)
So, SecondTaskVC will look like this,
class SecondTaskVC: UIViewController {
var weatherModel: WeatherModelDecodable?
override func viewDidLoad() {
let url = URL(string: "https://api.openweathermap.org/data/2.5/forecast?lat=42.874722&lon=74.612222&APPID=079587841f01c6b277a82c1c7788a6c3")
Alamofire.request(url!).responseJSON { (response) in
let result = response.data
do{
let decoder = JSONDecoder()
self.weatherModel = try decoder.decode(WeatherModelDecodable.self, from: result!)
print(self.weatherModel!.city.name)
}catch let error{
print("error in decoding",error.localizedDescription)
}
}
}
}
You should decode the respective objects with the same structure you are getting in the response.