Simple and clean way to convert JSON string to Object in Swift

Question

I have been searching for days to convert a fairly simple JSON string to an object type in Swift but with no avail.

Here is the code for web service call:

func GetAllBusiness() {          Alamofire.request(.GET, "http://MyWebService/").responseString { (request, response, string, error) in                  println(string)          } } 

I have a swift struct Business.swift:

struct Business {     var Id : Int = 0     var Name = ""     var Latitude = ""     var Longitude = ""     var Address = "" } 

Here is my test service deployed:

[   {     "Id": 1,     "Name": "A",     "Latitude": "-35.243256",     "Longitude": "149.110701",     "Address": null   },   {     "Id": 2,     "Name": "B",     "Latitude": "-35.240592",     "Longitude": "149.104843",     "Address": null   }   ... ] 

It would be a delight if someone guide me through this.

Thanks.

Answer 1

for swift 3/4

extension String {     func toJSON() -> Any? {         guard let data = self.data(using: .utf8, allowLossyConversion: false) else { return nil }         return try? JSONSerialization.jsonObject(with: data, options: .mutableContainers)     } } 

Example Usage:

 let dict = myString.toJSON() as? [String:AnyObject] // can be any type here 

Answer 2

Here are some tips how to begin with simple example.

Consider you have following JSON Array String (similar to yours) like:

 var list:Array<Business> = []    // left only 2 fields for demo   struct Business {     var id : Int = 0     var name = ""                 }   var jsonStringAsArray = "[\n" +         "{\n" +         "\"id\":72,\n" +         "\"name\":\"Batata Cremosa\",\n" +                     "},\n" +         "{\n" +         "\"id\":183,\n" +         "\"name\":\"Caldeirada de Peixes\",\n" +                     "},\n" +         "{\n" +         "\"id\":76,\n" +         "\"name\":\"Batata com Cebola e Ervas\",\n" +                     "},\n" +         "{\n" +         "\"id\":56,\n" +         "\"name\":\"Arroz de forma\",\n" +                 "}]"           // convert String to NSData         var data: NSData = jsonStringAsArray.dataUsingEncoding(NSUTF8StringEncoding)!         var error: NSError?          // convert NSData to 'AnyObject'         let anyObj: AnyObject? = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions(0),             error: &error)         println("Error: \(error)")       // convert 'AnyObject' to Array<Business>      list = self.parseJson(anyObj!)       //===============      func parseJson(anyObj:AnyObject) -> Array<Business>{          var list:Array<Business> = []           if  anyObj is Array<AnyObject> {              var b:Business = Business()              for json in anyObj as Array<AnyObject>{              b.name = (json["name"] as AnyObject? as? String) ?? "" // to get rid of null              b.id  =  (json["id"]  as AnyObject? as? Int) ?? 0                                  list.append(b)             }// for          } // if        return list      }//func     

[EDIT]

To get rid of null changed to:

b.name = (json["name"] as AnyObject? as? String) ?? "" b.id  =  (json["id"]  as AnyObject? as? Int) ?? 0  

See also Reference of Coalescing Operator (aka ??)

Hope it will help you to sort things out,