100

I have a JSON file, want to parse and use list of objects in table view. Can any one share the code to parse JSON file in swift.

rmaddy
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kmithi1
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    There is a tutorial [here](http://jamesonquave.com/blog/developing-ios-apps-using-swift-tutorial-part-2/) that does a URL request and loads the results in a UITableView – Chris Stokes Jun 03 '14 at 11:04
  • I wrote an API fully up to date for Swift 3: https://github.com/borchero/WebParsing – borchero Sep 29 '16 at 20:23

18 Answers18

109

This answer was last revised for Swift 5.3 and iOS 14.4 SDK.


Given some already obtained JSON data, you can use JSONDecoder to decode it into your Decodable model (or a collection of models).

let data: Data = /* obtain your JSON data */
let model = try JSONDecoder().decode(Model.self, from: data)

Such model must conform to the Decodable protocol and contain correct mapping between properties and JSON dictionary keys. As an example, consider the following JSON array containing search results of cities beginning with "Wa".

[
    {
        "id": 123,
        "city": "Washington",
        "region": "D.C.",
        "country": "United States"
    },
    {
        "id": 456,
        "city": "Warsaw",
        "region": "Mazowieckie",
        "country": "Poland"
    },
    ...
]

For that, you need to create a model that contains the correct properties of correct types. If you're using a web API, its documentation will be of great help here.

struct SearchResult: Decodable {
    let id: Int
    let city: String
    let region: String
    let country: String
}

Then decode the data with JSONDecoder:

let results = try JSONDecoder().decode([SearchResult].self, from: data)

Given a new array of decoded search results, call one of UITableView's functions to reload its data. Note that the decode function can throw an error which you must somehow handle.

To learn more about decoding custom types in Swift and more advanced usage of the Codable APIs, I recommend checking out this documentation article.

akashivskyy
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  • Forgive my ignorance, but what goes in the "/* get your son data */"? Is that a path? – tubuliferous Jun 05 '14 at 05:49
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    For example, `let jsonData = NSData.dataWithContentsOfFile(filepath, options: .DataReadingMappedIfSafe, error: nil)` – Caroline Jun 05 '14 at 06:30
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    The problem with this approach is that you end up with a bunch of foundation objects. Namely NSString, NSNumber, NSArray, NSDictionary, or NSNull. Which creates a heck of a down casting burden if you want to deal with native Swift typed later on in your code. Especially if you have nested dictionaries and arrays. Does anyone know how to deal with this? – califrench Jul 07 '14 at 03:42
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    These types are bridged between Swift and Obj-C. – akashivskyy Jul 07 '14 at 11:07
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    The correct way to load a file in iOS 8.1 seems to be: `NSData(contentsOfFile: path)`. See https://developer.apple.com/library/ios/documentation/Cocoa/Reference/Foundation/Classes/NSData_Class/index.html#//apple_ref/occ/instm/NSData/initWithContentsOfFile: – Claude Jan 10 '15 at 13:32
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    if you have been finding this answer everywhere u google and no one ever tells u wtf is NSData. just do this: `var jsonStr = "{\"hi\":\"bye\"}";` `var data = jsonStr.dataUsingEncoding(NSASCIIStringEncoding, allowLossyConversion: false)` – bubakazouba Jul 23 '15 at 18:18
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    @bubakazouba: Pity I can't downvote a comment. Couple of things: 1. Caroline already provided a snippet for loading data from a file (which is what OP wanted). 2. Your code uses ASCII encoding which loses all unicode symbols, including beyond-English language support. – akashivskyy Jul 24 '15 at 09:37
44

Making the API Request

var request: NSURLRequest = NSURLRequest(URL: url)
var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: false)

Preparing for the response

Declare an array as below

var data: NSMutableData = NSMutableData()

Receiving the response

1.

func connection(didReceiveResponse: NSURLConnection!, didReceiveResponse response: NSURLResponse!) {
   // Received a new request, clear out the data object
   self.data = NSMutableData()
}

2.

func connection(connection: NSURLConnection!, didReceiveData data: NSData!) {
   // Append the received chunk of data to our data object
   self.data.appendData(data)
}

3.

func connectionDidFinishLoading(connection: NSURLConnection!) {
   // Request complete, self.data should now hold the resulting info
   // Convert the retrieved data in to an object through JSON deserialization
   var err: NSError
   var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary

   if jsonResult.count>0 && jsonResult["results"].count>0 {
      var results: NSArray = jsonResult["results"] as NSArray
      self.tableData = results
      self.appsTableView.reloadData()

   }
}

When NSURLConnection receives a response, we can expect the didReceiveResponse method to be called on our behalf. At this point we simply reset our data by saying self.data = NSMutableData(), creating a new empty data object.

After a connection is made, we will start receiving data in the method didReceiveData. The data argument being passed in here is where all our juicy information comes from. We need to hold on to each chunk that comes in, so we append it to the self.data object we cleared out earlier.

Finally, when the connection is done and all data has been received, connectionDidFinishLoading is called and we’re ready to use the data in our app. Hooray!

The connectionDidFinishLoading method here uses the NSJSONSerialization class to convert our raw data in to useful Dictionary objects by deserializing the results from your Url.

Olcay Ertaş
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Kirit Modi
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19

I just wrote a class called JSON, which makes JSON handling in Swift as easy as JSON object in ES5.

Turn your swift object to JSON like so:

let obj:[String:AnyObject] = [
    "array": [JSON.null, false, 0, "",[],[:]],
    "object":[
        "null":   JSON.null,
        "bool":   true,
        "int":    42,
        "double": 3.141592653589793,
        "string": "a α\t弾\n",
        "array":  [],
        "object": [:]
    ],
    "url":"http://blog.livedoor.com/dankogai/"
]

let json = JSON(obj)
json.toString()

...or string...

let json = JSON.parse("{\"array\":[...}")

...or URL.

let json = JSON.fromURL("http://api.dan.co.jp/jsonenv")
Tree Traversal

Just traverse elements via subscript:

json["object"]["null"].asNull       // NSNull()
// ...
json["object"]["string"].asString   // "a α\t弾\n"
json["array"][0].asNull             // NSNull()
json["array"][1].asBool             // false
// ...

Just like SwiftyJSON you don't worry if the subscripted entry does not exist.

if let b = json["noexistent"][1234567890]["entry"].asBool {
    // ....
} else {
    let e = json["noexistent"][1234567890]["entry"].asError
    println(e)
}

If you are tired of subscripts, add your scheme like so:

//// schema by subclassing
class MyJSON : JSON {
    init(_ obj:AnyObject){ super.init(obj) }
    init(_ json:JSON)  { super.init(json) }
    var null  :NSNull? { return self["null"].asNull }
    var bool  :Bool?   { return self["bool"].asBool }
    var int   :Int?    { return self["int"].asInt }
    var double:Double? { return self["double"].asDouble }
    var string:String? { return self["string"].asString }
}

And you go:

let myjson = MyJSON(obj)
myjson.object.null
myjson.object.bool
myjson.object.int
myjson.object.double
myjson.object.string
// ...

Hope you like it.

With the new xCode 7.3+ its important to add your domain to the exception list (How can I add NSAppTransportSecurity to my info.plist file?), refer to this posting for instructions, otherwise you will get a transport authority error.

Community
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dankogai
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  • A question regarding your Github repo: how you actually execute the main.swift? I am having trouble executing it from within the playground as you cant seem to refer to classes defined in your own project from the playground (?!) thanks! – Janos Jul 22 '14 at 05:50
  • I've marked methods public in the latest repo. That makes the minimum requirement to Beta4 so don't forget to upgrade Xcode before try – dankogai Jul 22 '14 at 19:11
  • Ok thanks, I was really looking for how exactly to execute the example code. I tried playgroung but it didn't work as I was unable to reference the JSON class (its a known issue you cant refer to the classes in your project) – Janos Jul 23 '14 at 06:12
  • I can't make it work :( This time I'm not trying to use it in playground, I've added your json.swift to my project and in another class I'm trying to use it. It does not work. I tried the simplest JSON: { "id": "Janos" }, created the JSON object, called its toString method, it spits out the file contents correctly, however when I call myJson["id"].asString I get nil. What am I missing? – Janos Jul 23 '14 at 12:50
  • I was trying to construct a JSON object passing a String in the constructor... I've changed to how you do in the example now it works a treat. Only question is which one to use now, yours or SwiftyJSon :) – Janos Jul 24 '14 at 07:21
  • Ok, I have an answer for this as well :) Yours is better at handling non existing nodes, it simply returns nil. I still have the question around how you actually run main.swift, could you please advise? – Janos Jul 24 '14 at 13:15
  • Okay so I have a question, is this better than swiftyjson? – Marin Jul 29 '14 at 12:56
  • To run main.swift which is a demonstrator. Simply: xcrun swift -i *.swift – dankogai Jul 29 '14 at 16:52
  • How to declare global value ? i set my data is NSDictionary : var apidata = [NSDictionary] () but return error: 'NSDictionary' is not identical to 'AnyObject' – TomSawyer Sep 01 '14 at 20:19
  • In the new swift to get this to work remember to make an exception for your domain name or you will get an error from the transport authority. You can set this in your info.plist. Refer to this posting (http://stackoverflow.com/questions/31216758/how-can-i-add-nsapptransportsecurity-to-my-info-plist-file) – Joseph Astrahan Mar 10 '16 at 11:11
6

Codable

In Swift 4+ is strongly recommended to use Codable instead of JSONSerialization.

This Codable includes two protocols: Decodable and Encodable. This Decodable protocol allows you to decode Data in JSON format to custom struct/class conforming to this protocol.

For example imagine situation that we have this simple Data (array of two objects)

let data = Data("""
[
    {"name":"Steve","age":56}, 
    {"name":"iPhone","age":11}
]
""".utf8)

then have following struct and implement protocol Decodable

struct Person: Decodable {
    let name: String
    let age: Int
}

now you can decode your Data to your array of Person using JSONDecoder where first parameter is type conforming to Decodable and to this type should Data be decoded

do {
    let people = try JSONDecoder().decode([Person].self, from: data)
} catch { print(error) }

... note that decoding has to be marked with try keyword since you could for example make some mistake with naming and then your model can't be decoded correctly ... so you should put it inside do-try-catch block


Cases that key in json is different from name of property:

  • If key is in named using snake_case, you can set decoder's keyDecodingStrategy to convertFromSnakeCase which changes key from property_name to camelCase propertyName

    let decoder = JSONDecoder()
    decoder.keyDecodingStrategy = .convertFromSnakeCase
    let people = try decoder.decode([Person].self, from: data)
    
  • If you need unique name you can use coding keys inside struct/class where you declare name of key

    let data = Data(""" 
    { "userName":"Codable", "age": 1 } 
    """.utf8)
    
    struct Person: Decodable {
    
        let name: String
        let age: Int
    
        enum CodingKeys: String, CodingKey {
            case name = "userName"
            case age
        }
    }
    
Robert Dresler
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5

Here is a code to make the conversions between JSON and NSData in Swift 2.0

// Convert from NSData to json object
func nsdataToJSON(data: NSData) -> AnyObject? {
    do {
        return try NSJSONSerialization.JSONObjectWithData(data, options: .MutableContainers)
    } catch let myJSONError {
        print(myJSONError)
    }
    return nil
}

// Convert from JSON to nsdata
func jsonToNSData(json: AnyObject) -> NSData?{
    do {
        return try NSJSONSerialization.dataWithJSONObject(json, options: NSJSONWritingOptions.PrettyPrinted)
    } catch let myJSONError {
        print(myJSONError)
    }
    return nil;
}
Ciprian Rarau
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4
  1. Install Swifty Json

Note: if you are looking for this, there's also a high chance you don't know how to install swifty. Follow the instructions here.

sudo gem install cocoapods

cd ~/Path/To/Folder/Containing/ShowTracker

Next enter this command:

pod init

This will create a default Podfile for your project. The Podfile is where you define the dependencies your project relies on.

Type this command to open Podfile using Xcode for editing:

open -a Xcode Podfile

Add the Swifty into the podfile

platform :ios, '8.0'
use_frameworks!

target 'MyApp' do
    pod 'SwiftyJSON', '~> X.X.X'
end
  1. Check this example
var mURL = NSURL(string: "http://api.openweathermap.org/data/2.5/weather?q=London,uk&units=metric")

if mURL == nil{
    println("You are stupid")
    return
}

var request = NSURLRequest(URL: mURL!)

NSURLConnection.sendAsynchronousRequest(
    request,
    queue: NSOperationQueue.mainQueue(),
    completionHandler:{ (
        response: NSURLResponse!, 
        data: NSData!, 
        error: NSError!) -> Void in

    if data != nil {

        var mJSON = JSON(data: data!)

        if let current_conditions = mJSON["weather"][0]["description"].string {
            println("Current conditions: " + current_conditions)
        } else {
            println("MORON!")
        }

        if let current_temperature = mJSON["main"]["temp"].double {
            println("Temperature: "+ String(format:"%.f", current_temperature)  + "°C"
        } else {
            println("MORON!")
        }
    }
})
Olcay Ertaş
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OWADVL
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3

I also wrote a small library which is specialized for the mapping of the json response into an object structure. I am internally using the library json-swift from David Owens. Maybe it is useful for someone else.

https://github.com/prine/ROJSONParser

Example Employees.json

{
"employees": [
  {
    "firstName": "John",
    "lastName": "Doe",
    "age": 26
  },
  {
    "firstName": "Anna",
    "lastName": "Smith",
    "age": 30
  },
  {
    "firstName": "Peter",
    "lastName": "Jones",
    "age": 45
  }]
}

As next step you have to create your data model (EmplyoeeContainer and Employee).

Employee.swift

class Employee : ROJSONObject {

    required init() {
        super.init();
    }

    required init(jsonData:AnyObject) {
        super.init(jsonData: jsonData)
    }

    var firstname:String {
        return Value<String>.get(self, key: "firstName")
    }

    var lastname:String {
        return Value<String>.get(self, key: "lastName")            
    }

    var age:Int {
        return Value<Int>.get(self, key: "age")
    }
}

EmployeeContainer.swift

class EmployeeContainer : ROJSONObject {
    required init() {
        super.init();
    }

    required init(jsonData:AnyObject) {
        super.init(jsonData: jsonData)
    }

    lazy var employees:[Employee] = {
        return Value<[Employee]>.getArray(self, key: "employees") as [Employee]
    }()
}

Then to actually map the objects from the JSON response you only have to pass the data into the EmployeeContainer class as param in the constructor. It does automatically create your data model.

 var baseWebservice:BaseWebservice = BaseWebservice();

  var urlToJSON = "http://prine.ch/employees.json"

  var callbackJSON = {(status:Int, employeeContainer:EmployeeContainer) -> () in
    for employee in employeeContainer.employees {
      println("Firstname: \(employee.firstname) Lastname: \(employee.lastname) age: \(employee.age)")
    }
  }

  baseWebservice.get(urlToJSON, callback:callbackJSON)

The console output looks then like the following:

Firstname: John Lastname: Doe age: 26
Firstname: Anna Lastname: Smith age: 30
Firstname: Peter Lastname: Jones age: 45
Prine
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2

SwiftJSONParse: Parse JSON like a badass

Dead-simple and easy to read!

Example: get the value "mrap" from nicknames as a String from this JSON response

{
    "other": {
        "nicknames": ["mrap", "Mikee"]
}

It takes your json data NSData as it is, no need to preprocess.

let parser = JSONParser(jsonData)

if let handle = parser.getString("other.nicknames[0]") {
    // that's it!
}

Disclaimer: I made this and I hope it helps everyone. Feel free to improve on it!

Mike Rapadas
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  • Forgive my ignorance. What are the advantages of using your library over one like SwiftyJSON? – Levi Roberts Jan 13 '15 at 10:41
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    Initially, I built this because I didn't like the idea of language hacking operators/symbols. Also, I built it to familiarize myself with Swift. Out of curiosity I ran a benchmark, and found SwiftyJSON to have superior speed (~2 - 7 times faster). I've updated the repo's README to admit it. – Mike Rapadas Jan 22 '15 at 09:03
  • Can you show an example of how you would load an array of data from the JSON (multiple items essentially with a loop etc...) – Joseph Astrahan Mar 08 '16 at 06:15
2

Parsing JSON in Swift is an excellent job for code generation. I've created a tool at http://www.guideluxe.com/JsonToSwift to do just that.

You supply a sample JSON object with a class name and the tool will generate a corresponding Swift class, as well as any needed subsidiary Swift classes, to represent the structure implied by the sample JSON. Also included are class methods used to populate Swift objects, including one that utilizes the NSJSONSerialization.JSONObjectWithData method. The necessary mappings from the NSArray and NSDictionary objects are provided.

From the generated code, you only need to supply an NSData object containing JSON that matches the sample provided to the tool.

Other than Foundation, there are no dependencies.

My work was inspired by http://json2csharp.com/, which is very handy for .NET projects.

Here's how to create an NSData object from a JSON file.

let fileUrl: NSURL = NSBundle.mainBundle().URLForResource("JsonFile", withExtension: "json")!
let jsonData: NSData = NSData(contentsOfURL: fileUrl)!
Perry Tribolet
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    What issues are you having? – Perry Tribolet Mar 10 '16 at 23:21
  • Sorry about that, I was pasting JSON URL directly, it works well by pasting the JSON response. Would be fabulous to have URL pasted directly though. But brilliant job for this utility. Thanks. – ioopl Mar 13 '16 at 12:29
  • The tool you’ve created is simply awesome. I am using this tool since last 6 months. But suddenly since last 3 days your website is not reachable & browser is responding with “This site can’t be reached ” this message. So, what’s the reason behind this? – Saif Sep 26 '16 at 11:39
2

Swift 3

let parsedResult: [String: AnyObject]
do {      
    parsedResult = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as! [String:AnyObject]       
} catch {        
    // Display an error or return or whatever
}

data - it's Data type (Structure) (i.e. returned by some server response)

Olcay Ertaş
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Andrew
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1

The entire viewcontroller which show data in collecction view using two methods of json parsig

@IBOutlet weak var imagecollectionview: UICollectionView!
lazy var data = NSMutableData()
var dictdata : NSMutableDictionary = NSMutableDictionary()
override func viewDidLoad() {
    super.viewDidLoad()
    startConnection()
    startNewConnection()
    // Do any additional setup after loading the view, typically from a nib.
}


func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return dictdata.count
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

    let cell  = collectionView.dequeueReusableCellWithReuseIdentifier("CustomcellCollectionViewCell", forIndexPath: indexPath) as! CustomcellCollectionViewCell
    cell.name.text = dictdata.valueForKey("Data")?.valueForKey("location") as? String
    let url = NSURL(string: (dictdata.valueForKey("Data")?.valueForKey("avatar_url") as? String)! )

    LazyImage.showForImageView(cell.image, url:"URL
    return cell
}
func collectionView(collectionView: UICollectionView,
                    layout collectionViewLayout: UICollectionViewLayout,
                           sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    let kWhateverHeightYouWant = 100
    return CGSizeMake(self.view.bounds.size.width/2, CGFloat(kWhateverHeightYouWant))
}

func startNewConnection()
{

   let url: URL = URL(string: "YOUR URL" as String)!
    let session = URLSession.shared

    let request = NSMutableURLRequest(url: url as URL)
    request.httpMethod = "GET" //set the get or post according to your request

    //        request.cachePolicy = NSURLRequest.CachePolicy.ReloadIgnoringCacheData
    request.cachePolicy = NSURLRequest.CachePolicy.reloadIgnoringCacheData

    let task = session.dataTask(with: request as URLRequest) {
        ( data, response, error) in

        guard let _:NSData = data as NSData?, let _:URLResponse = response, error == nil else {
            print("error")
            return
        }

       let jsonString = NSString(data: data!, encoding:String.Encoding.utf8.rawValue) as! String
               }
    task.resume()

}

func startConnection(){
    let urlPath: String = "your URL"
    let url: NSURL = NSURL(string: urlPath)!
    var request: NSURLRequest = NSURLRequest(URL: url)
    var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: false)!
    connection.start()
}

func connection(connection: NSURLConnection!, didReceiveData data: NSData!){
    self.data.appendData(data)
}

func buttonAction(sender: UIButton!){
    startConnection()
}

func connectionDidFinishLoading(connection: NSURLConnection!) {
    do {
        let JSON = try NSJSONSerialization.JSONObjectWithData(self.data, options:NSJSONReadingOptions(rawValue: 0))
        guard let JSONDictionary :NSDictionary = JSON as? NSDictionary else {
            print("Not a Dictionary")
            // put in function
            return
        }
        print("JSONDictionary! \(JSONDictionary)")
        dictdata.setObject(JSONDictionary, forKey: "Data")

        imagecollectionview.reloadData()
    }
    catch let JSONError as NSError {
        print("\(JSONError)")
    }    }
Amol Pokale
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1

Using ObjectMapper framework

if let path = Bundle(for: BPPView.self).path(forResource: jsonFileName, ofType: "json") {
    do {
        let data = try Data(contentsOf: URL(fileURLWithPath: path), options: NSData.ReadingOptions.mappedIfSafe)
        let json = try JSONSerialization.jsonObject(with: data, options: .allowFragments)
        self.levels = Mapper<Level>().mapArray(JSONArray: (json as! [[String : Any]]))!
        print(levels.count)
    } catch let error as NSError {
        print(error.localizedDescription)
    }
} else {
    print("Invalid filename/path.")
}

Before you should prepare the set of appropriate :Mappable objects to parse into

import UIKit 
import ObjectMapper
class Level: Mappable {
var levelName = ""
var levelItems = [LevelItem]()

required init?(map: Map) {

}

// Mappable
func mapping(map: Map) {
    levelName <- map["levelName"]
    levelItems <- map["levelItems"]
}

 import UIKit 
import ObjectMapper 
class LevelItem: Mappable {
var frontBackSide = BPPFrontBack.Undefined
var fullImageName = ""
var fullImageSelectedName = ""
var bodyParts = [BodyPart]()

required init?(map: Map) {

}

// Mappable
func mapping(map: Map) {
    frontBackSide <- map["frontBackSide"]
    fullImageName <- map["fullImageName"]
    fullImageSelectedName <- map["fullImageSelectedName"]
    bodyParts <- map["bodyParts"]
}}
Olcay Ertaş
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Naloiko Eugene
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1

Swift 4 API Request Example

Make use of JSONDecoder().decode

See this video JSON parsing with Swift 4


struct Post: Codable {
    let userId: Int
    let id: Int
    let title: String
    let body: String
}

URLSession.shared.dataTask(with: URL(string: "https://jsonplaceholder.typicode.com/posts")!) { (data, response, error) in

    guard let response = response as? HTTPURLResponse else {
        print("HTTPURLResponse error")
        return
    }

    guard 200 ... 299 ~= response.statusCode else {
        print("Status Code error \(response.statusCode)")
        return
    }

    guard let data = data else {
        print("No Data")
        return
    }

    let posts = try! JSONDecoder().decode([Post].self, from: data)
    print(posts)      
}.resume()
Olcay Ertaş
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Warif Akhand Rishi
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0

This parser uses generics to cast JSON to Swift types which reduces the code you need to type.

https://github.com/evgenyneu/JsonSwiftson

struct Person {
  let name: String?
  let age: Int?
}

let mapper = JsonSwiftson(json: "{ \"name\": \"Peter\", \"age\": 41 }")

let person: Person? = Person(
  name: mapper["name"].map(),
  age: mapper["age"].map()
)
Evgenii
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0

Swift 2 iOS 9

let miadata = NSData(contentsOfURL: NSURL(string: "https://myWeb....php")!)

do{
    let MyData = try NSJSONSerialization.JSONObjectWithData(miadata!, options: NSJSONReadingOptions.MutableContainers) as? NSArray
    print(".........\(MyData)")    
}
catch let error as NSError{
    // error.description
    print(error.description)
}
Olcay Ertaş
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RobertoL
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0

Below is a Swift Playground example:

import UIKit

let jsonString = "{\"name\": \"John Doe\", \"phone\":123456}"

let data = jsonString.data(using: .utf8)

var jsonObject: Any
do {
    jsonObject = try JSONSerialization.jsonObject(with: data!) as Any

    if let obj = jsonObject as? NSDictionary {
        print(obj["name"])
    }
} catch {
    print("error")
}
rsc
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0

Swift 4

Create a Project

Design StoryBoard With a Button and a UITableview

Create TableViewCell VC

In Button Action Insert the folloeing Codes

Remember This Code for Fetch Array of Data in an Api

import UIKit

class ViewController3: UIViewController,UITableViewDelegate,UITableViewDataSource {

    @IBOutlet var tableView: UITableView!
    var displayDatasssss = [displyDataClass]()
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return displayDatasssss.count
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCell1") as! TableViewCell1
        cell.label1.text = displayDatasssss[indexPath.row].email
        return cell
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func gettt(_ sender: Any) {

        let url = "http://jsonplaceholder.typicode.com/users"
        var request = URLRequest(url: URL(string: url)!)
        request.httpMethod = "GET"
        let configuration = URLSessionConfiguration.default
        let session = URLSession(configuration: configuration, delegate: nil, delegateQueue: OperationQueue.main)
        let task = session.dataTask(with: request){(data, response,error)in
            if (error != nil){
                print("Error")
            }
            else{
                do{
                    // Array of Data 
                    let fetchData = try JSONSerialization.jsonObject(with: data!, options: .mutableLeaves) as! NSArray

                    for eachData in fetchData {

                        let eachdataitem = eachData as! [String : Any]
                        let name = eachdataitem["name"]as! String
                        let username = eachdataitem["username"]as! String

                        let email = eachdataitem["email"]as! String
                         self.displayDatasssss.append(displyDataClass(name: name, username: username,email : email))
                    }
                    self.tableView.reloadData()
                }
                catch{
                    print("Error 2")
                }

            }
        }
        task.resume()

    }
}
class displyDataClass {
    var name : String
    var username : String
    var email : String

    init(name : String,username : String,email :String) {
        self.name = name
        self.username = username
        self.email = email
    }
}

This is for Dictionary data Fetching

import UIKit

class ViewController3: UIViewController,UITableViewDelegate,UITableViewDataSource {

    @IBOutlet var tableView: UITableView!
    var displayDatasssss = [displyDataClass]()
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return displayDatasssss.count
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCell1") as! TableViewCell1
        cell.label1.text = displayDatasssss[indexPath.row].email
        return cell
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func gettt(_ sender: Any) {

        let url = "http://jsonplaceholder.typicode.com/users/1"
        var request = URLRequest(url: URL(string: url)!)
        request.httpMethod = "GET"
        let configuration = URLSessionConfiguration.default
        let session = URLSession(configuration: configuration, delegate: nil, delegateQueue: OperationQueue.main)
        let task = session.dataTask(with: request){(data, response,error)in
            if (error != nil){
                print("Error")
            }
            else{
                do{
                    //Dictionary data Fetching
                    let fetchData = try JSONSerialization.jsonObject(with: data!, options: .mutableLeaves) as! [String: AnyObject]
                        let name = fetchData["name"]as! String
                        let username = fetchData["username"]as! String

                        let email = fetchData["email"]as! String
                         self.displayDatasssss.append(displyDataClass(name: name, username: username,email : email))

                    self.tableView.reloadData()
                }
                catch{
                    print("Error 2")
                }

            }
        }
        task.resume()

    }
}
class displyDataClass {
    var name : String
    var username : String
    var email : String

    init(name : String,username : String,email :String) {
        self.name = name
        self.username = username
        self.email = email
    }
}
Tony Franzis
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0

Swift 5+ & Xcode 13 Working example

Json response

[
  {
    "userId": 1,
    "id": 1,
    "title": "sunt aut facere repellat provident occaecati excepturi optio reprehenderit",
    "body": "quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto"
  },
  {
    "userId": 1,
    "id": 2,
    "title": "qui est esse",
    "body": "est rerum tempore vitae\nsequi sint nihil reprehenderit dolor beatae ea dolores neque\nfugiat blanditiis voluptate porro vel nihil molestiae ut reiciendis\nqui aperiam non debitis possimus qui neque nisi nulla"
  },
]

Model class

struct PostsModel : Decodable {
    let userId : Int?
    let id : Int?
    let title : String?
    let body : String?
}

Fetch Response

let url = URL(string: K.GET_POSTS)!
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
        let task = URLSession.shared.dataTask(with: request) { data, response, error in
            guard let safeData = data,
                let response = response as? HTTPURLResponse,
                error == nil else {                                              // check for fundamental networking error
                print("error", error ?? "Unknown error")
                delegate?.onError(error!)
                return
            }

            guard (200 ... 299) ~= response.statusCode else {                    // check for http errors
                print("statusCode should be 2xx, but is \(response.statusCode)")
                print("response = \(response)")
                return
            }

            let responseString = String(data: safeData, encoding: .utf8)
            do {
                let decoder = JSONDecoder()
            let loginResponseModel =  try decoder.decode([PostsModel].self, from: data!)

            }
            catch {
                print(error)
            }
            print("responseString = \(responseString)")
        }

        task.resume()
Quick learner
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