I am using URLSession right now. I want to print only the profile value among the userId and profile in the data value here. How can I print it?
Some of my code
if let httpResponse = response as? HTTPURLResponse {
print( httpResponse.allHeaderFields )
guard let data = data else {return}
print( String (data: data, encoding: .utf8) ?? "" )
let profile = "{\"profile\":\"\(data.profile ?? "")}" // ERROR [Value of type 'Data' has no member 'profile']
}
print (String (data: data, encoding: .utf8) ??"") <When I run this code, I get the result like this. userId and profile I want to display only the profile excluding the userId. Thanks for reading.
I'd define a type conforming to the Codable protocol and use a JSONDecoder to decode your data to something user friendly.
struct UserData: Codable {
let userId: String
let profile: String
}
Here's how to decode your data:
if let httpResponse = response as? HTTPURLResponse {
guard let data = data else { return }
let decoder = JSONDecoder()
do {
let userData = try decoder.decode(UserData.self, from: data)
print(userData.profile)
} catch {
print("Error: \(error)")
}
}
You can convert data to json and use however you want
json = try JSON(data: data)
if you want to parse it easily use SwiftyJson
Related
I am trying to create some structs to decode some JSON received from an API using JSONSerialization.jsonObject(with: data, options: [])
This is what the JSON looks like:
{"books":[{"title":"The Fountainhead.","author":"Ayn Ranyd"},{"title":"Tom Sawyer","author":"Mark Twain"},{"title":"Warhol","author":"Blake Gopnik"}]}
Here are the structs that I am trying to use for decoding.
struct BooksReturned : Codable {
let books : [Book]?
}
struct Book : Codable {
let BookParts: Array<Any>?
}
struct BookParts : Codable {
let titleDict : Dictionary<String>?
let authorDict : Dictionary<String>?
}
The error is:
The given data was not valid JSON.", underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840 "JSON text did not start with array or object and option to allow fragments not set." UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.})))
The non-working code I am using to decode is:
let task = session.dataTask(with: url) { data, response, error in
if let data = data, error == nil {
let nsdata = NSData(data: data)
DispatchQueue.main.async {
if let str = String(data: data, encoding: .utf8) {
let json = try? JSONSerialization.jsonObject(with: data, options: [])
do {
let mybooks = try JSONDecoder().decode(BooksReturned.self, from: data)
//do something with book
}
} catch {
print(error.localizedDescription)
print(error)
}
}
}
} else {
// Failure
}
}
task.resume()
}
I have some very limited ability to change JSON. The only thing I can do is remove the "books" : Everything else is received from an external API.
Thanks for any suggestions on how to get this to work.
The JSON you provided seems to be valid. Modify your Book model and the decoding part as the following.
Model:
struct Book: Codable {
let title, author: String
}
Decoding:
let task = session.dataTask(with: url) { data, response, error in
if let data = data, error == nil {
DispatchQueue.main.async {
do {
let mybooks = try JSONDecoder().decode(BooksReturned.self, from: data)
print(mybooks)
}
} catch {
print(error.localizedDescription)
print(error)
}
}
} else {
// Failure
}
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 have an Error in parsing JSON Format form an ASMX Web service,
My Code is
func getData() {
let url = URL(string: "http://192.168.11.188/getItems.asmx/theItems")
let theCategory = "ALL"
let theSubCategory = "ALL"
let postString = "theCategory=\(theCategory)&theSubCategory=\(theSubCategory)"
var request = URLRequest(url: url!)
request.httpMethod = "POST"
request.cachePolicy = NSURLRequest.CachePolicy.reloadIgnoringCacheData
request.httpBody = postString.data(using: String.Encoding.utf8)
URLSession.shared.dataTask(with: request) { (data, respons, error) in
if let error = error {
print("Error conning to server \(error)")
} else {
if let respons = respons as? HTTPURLResponse {
if respons.statusCode == 200 {
print(data!)
if let data = data {
do {
let json = try JSONDecoder().decode([ITEMS].self, from: data)
print(json)
} catch let parsingError {
print("Error parsing json \(parsingError)")
}
}
} else {
print("Error in responce code.... \(respons.statusCode)")
}
}
}
}.resume()
}
I am using the decoder struct in this code:
struct ITEMS: Codable {
let CODE:String
let CAT_ID:String
let SUB_ID:String
let PRODUCT_AR:String
let PRODUCT_EN:String
let OLD_PRICE:String
let NEW_PRICE:String
let UNIT:String
let BARCODE:String
let THE_DATE:String
let TIME:String
}
The JSON value is
{ ITEMS : [{"CODE":111,"CAT_ID":203,"SUB_ID":null,"PRODUCT_AR":"ITEM 1","PRODUCT_EN":"ITEM 1","OLD_PRICE":133.0035,"NEW_PRICE":109,"UNIT":null,"BARCODE":"328031002009","THE_DATE":"\/Date(1553673958397)\/","TIME":"11:05 AM"},
{"CODE":222,"CAT_ID":201,"SUB_ID":null,"PRODUCT_AR":"ITEM 2","PRODUCT_EN":"ITEM 2","OLD_PRICE":18.95,"NEW_PRICE":9.95,"UNIT":null,"BARCODE":"628103400012","THE_DATE":"\/Date(1553673958260)\/","TIME":"11:05 AM"}]}
but this code returns an Error
Error parsing JSON Error Domain=NSCocoaErrorDomain Code=3840 "JSON text did not start with array or object and option to allow fragments not set." UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}
What am I doing wrong?
as you are writing this,
let json = try JSONDecoder().decode([ITEMS].self, from: data)
it must ask for array of ITEMS to be parsed, but your JSON is just an object not an array (It starts with {ITEMS: [array_here]}).
For solving this issue, you need to make your struct like below and parse data into that object.
struct ITEMS: Codable {
let CODE:String
let CAT_ID:String
let SUB_ID:String
let PRODUCT_AR:String
let PRODUCT_EN:String
let OLD_PRICE:String
let NEW_PRICE:String
let UNIT:String
let BARCODE:String
let THE_DATE:String
let TIME:String
}
struct MyAPIData: Codable {
let ITEMS: [ITEMS]
}
Now parse data using below line of code,
let json = try JSONDecoder().decode(MyAPIData.self, from: data)
There were wrong types used in your struct, here is the fixed struct
struct ITEM: Codable {
let CODE:Int // not String
let CAT_ID:Int // not String
let SUB_ID:Int? // its null in JSON, use either Int? or String?
let PRODUCT_AR: String
let PRODUCT_EN: String
let OLD_PRICE:Double // not String
let NEW_PRICE:Double // not String
let UNIT:String?
let BARCODE:String
let THE_DATE:String
let TIME:String
}
Since you JSON has a root element ITEMS, you need to decode using this struct
struct BaseItems: Codable {
let ITEMS: [ITEM] // Actual array of items are within this JSON element
}
Usage:
do {
let decoded = try JSONDecoder().decode(BaseItems.self, from: data)
print(decoded.ITEMS)
} catch {
print(error)
}
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 am trying to parse some nested JSON retrieved through an API but am having trouble isolating specific key-value pairs. In fact, I have some confusion over the difference between the JSON data and the dictionary obtained through serialization.
To retrieve the data I am using:
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
return
}
To convert the data to a JSON dictionary, I am doing
do {
let stringDic = try JSONSerialization.jsonObject(with: data, options: []) as? [String : Any]
} catch let error {
print(error)
}
When printed, this produces nested output of the form:
Optional(["document_tone": {
"tone_categories" = (
{
"category_id" = "emotion_tone";
"category_name" = "Emotion Tone";
and so forth
My question is how can I get a unique value such as that for the key category_name?
If I try to use
let myCat = stringDic["category_name"]
Fix-it requires let document_tone = stringDic?["document_tone"] which if printed to console just prints whole dictionary over again.
Thanks in advance for any suggestions.
It's pretty easy: () is array, {} is dictionary and the compiler must know the static types of all subscripted objects:
if let documentTone = stringDic?["document_tone"] as? [String:Any],
let toneCategories = documentTone["tone_categories"] as? [[String:Any]] {
for category in toneCategories {
print(category["category_name"])
}
}
I think it's better to use Decodable
struct Root:Decodable {
let documentTone : InnerItem
}
struct InnerItem:Decodable {
let toneCategories: [BottomItem]
}
struct BottomItem:Decodable {
let categoryId: String
let categoryName: String
}
do {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let result = try decoder.decode(Root.self, from: data)
//print all names
result.documentTone.toneCategories.forEach {print($0.categoryName) }
} catch {
print(error)
}