"[{\"person\":\"person1\",\"data\":{\"age\":\"10\",\"name\":\"John\"}},
{\"person\":\"person2\",\"data\":{\"age\":\"20\",\"name\":\"Jonathan\"}},
{\"person\":\"person3\",\"data\":{\"age\":\"30\",\"name\":\"Joe\"}}]"
Note that the value "data" is also a dictionary.
I have a JSON string like above and am trying to serialize like:
if let dataFromString = conf.data(using: .utf8, allowLossyConversion: false) {
let json = try JSON(data: dataFromString)
configuration = json.dictionary ?? [:]
}
However configuration is always an empty dictionary.
You need to parse the JSON you've as an array of dictionaries of type [[String: Any]]. The better modern approach is to use Decodable model to decode the JSON.
let string = """
[
{
"person": "person1",
"data": {
"age": "10",
"name": "John"
}
},
{
"person": "person2",
"data": {
"age": "20",
"name": "Jonathan"
}
},
{
"person": "person3",
"data": {
"age": "30",
"name": "Joe"
}
}
]
"""
let data = Data(string.utf8)
struct Person: Decodable {
let person: String
let data: PersonData
}
struct PersonData: Decodable {
let age, name: String
}
do {
let people = try JSONDecoder().decode([Person].self, from: data)
print(people)
} catch { print(error) }
For the JSON String,
let conf = "[{\"person\":\"person1\",\"data\":{\"age\":\"10\",\"name\":\"John\"}},{\"person\":\"person2\",\"data\":{\"age\":\"20\",\"name\":\"Jonathan\"}},{\"person\":\"person3\",\"data\":{\"age\":\"30\",\"name\":\"Joe\"}}]"
use JSONSerialization's jsonObject(with:options:) method to get the expected response.
if let conf = str.data(using: .utf8 ) {
do {
let dict = try JSONSerialization.jsonObject(with: data, options: []) as? [[String:Any]]
print(dict)
} catch {
print(error)
}
}
Related
I am new to swift . I created simple playground and added the file with extension json into playground . I am trying to decode the result and print the ID by using for loop but , I am getting following error ..
For-in loop requires 'People.Type' to conform to 'Sequence'
Here is my json file ..
{
"id": "1",
"options": [{
"id": "11",
"options": [{
"id": "111",
"options": []
}]
},
{
"id": "2",
"options": [{
"id": "21",
"options": []
},
{
"id": "22",
"options": [{
"id": "221",
"options": []
}]
}
]
}
]
}
Here is the code .. I tried ..
struct People: Codable {
let id: String
let options: [People]
}
func loadJson(filename fileName: String) -> People? {
if let url = Bundle.main.url(forResource: fileName, withExtension: "json") {
do {
let data = try Data(contentsOf: url)
let decoder = JSONDecoder()
let jsonData = try decoder.decode(People.self, from: data)
print("// Printing the ID of the Decode Json")
for jsondata in jsonData {
print("ID: \(jsonData.id)")
}
return jsonData
} catch {
print("error:\(error)")
}
}
return nil
}
loadJson(filename: "people1")
Here is the screenshot of the error ..
Here I got to run exactly what you are asking for, however I think you should probably consider renaming your struct to something like Person as #Vadian suggested.
struct People: Codable {
let id: String
let options: [People]
}
func loadJson(filename fileName: String) -> People? {
if let url = Bundle.main.url(forResource: fileName, withExtension: "json") {
do {
let data = try Data(contentsOf: url)
let decoder = JSONDecoder()
let jsonData = try decoder.decode(People.self, from: data)
printPeople(people: [jsonData])
return jsonData
} catch {
print("error:\(error)")
}
}
return nil
}
func printPeople(people: [People]) {
for person in people {
print(person.id)
if (!person.options.isEmpty) {
printPeople(people: person.options)
}
}
}
loadJson(filename: "people")
This will print:
1
11
111
2
21
22
221
I'm trying to filter JSON and get key & value to parse it. Here all JSON values are dynamic. Right now I need to find "type = object" if the type found is true then I need to check value ={"contentType" & "URL"}.
here is my JSON:
{
"date": {
"type": "String",
"value": "03/04/1982",
"valueInfo": {}
},
"Scanner": {
"type": "Object",
"value": {
"contentType": "image/jpeg ",
"url": "https://www.pexels.com/photo/neon-advertisement-on-library-glass-wall-9832438/",
"fileName": "sample.jpeg"
},
"valueInfo": {
"objectTypeName": "com.google.gson.JsonObject",
"serializationDataFormat": "application/json"
}
},
"startedBy": {
"type": "String",
"value": "super",
"valueInfo": {}
},
"name": {
"type": "String",
"value": "kucoin",
"valueInfo": {}
},
"ScannerDetails": {
"type": "Json",
"value": {
"accountNumber": "ANRPM2537J",
"dob": "03/04/1982",
"fathersName": "VASUDEV MAHTO",
"name": "PRAMOD KUMAR MAHTO"
},
"valueInfo": {}
}
}
decode code:
AF.request(v , method: .get, parameters: nil, encoding: URLEncoding.default, headers: headers).responseJSON { (response:AFDataResponse<Any>) in
print("process instance id api document view list::::",response.result)
switch response.result {
case .success:
let matchingUsers = response.value.flatMap { $0 }.flatMap { $0. == "object" }
print("new object doc:::", matchingUsers)
guard let data = response.value else {
return
}
print("new object doc:::", matchingUsers)
if let newJSON = response.value {
let json = newJSON as? [String: [String:Any]]
print("new object doc:::", json as Any)
// let dictAsString = self.asString(jsonDictionary: json)
let vc = self.stringify(json: json ?? [])
print("dictAsString ::: dictAsString::::==",vc)
let data = vc.data(using: .utf8)!
do{
let output = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String: [String:String]]
print ("demo:::==\(String(describing: output))")
}
catch {
print (error)
}
do {
if let jsonArray = try JSONSerialization.jsonObject(with: data, options : .allowFragments) as? [String: [String:String]]
{
print("json array::::",jsonArray) // use the json here
} else {
print("bad json")
}
} catch let error as NSError {
print(error)
}
}
self.view.removeLoading()
case .failure(let error):
print("Error:", error)
self.view.removeLoading()
}
}
How to get specific values from JSON? Any help is much appreciated pls...
Here is code from my playground with your json sample:
import Foundation
let json = """
{
"date": {
"type": "String",
"value": "03/04/1982",
"valueInfo": {}
},
"Scanner": {
"type": "Object",
"value": {
"contentType": "image/jpeg ",
"url": "https://www.pexels.com/photo/neon-advertisement-on-library-glass-wall-9832438/",
"fileName": "sample.jpeg"
},
"valueInfo": {
"objectTypeName": "com.google.gson.JsonObject",
"serializationDataFormat": "application/json"
}
},
"startedBy": {
"type": "String",
"value": "super",
"valueInfo": {}
},
"name": {
"type": "String",
"value": "kucoin",
"valueInfo": {}
},
"ScannerDetails": {
"type": "Json",
"value": {
"accountNumber": "ANRPM2537J",
"dob": "03/04/1982",
"fathersName": "VASUDEV MAHTO",
"name": "PRAMOD KUMAR MAHTO"
},
"valueInfo": {}
}
}
"""
let data = json.data(using: .utf8, allowLossyConversion: false)!
struct ObjectScanner: Decodable {
let contentType: String
let url: String
let fileName: String
}
enum ObjectScannerType {
case object(ObjectScanner)
}
struct Scanner: Decodable {
enum ScannerType: String, Decodable {
case object = "Object"
}
enum CodingKeys: String, CodingKey {
case type, value
}
let scanner: ObjectScannerType
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
let type = try container.decode(ScannerType.self, forKey: .type)
switch type {
case .object:
let value = try container.decode(ObjectScanner.self, forKey: .value)
scanner = .object(value)
}
}
}
struct DateResponse: Decodable {
let type: String
let value: String
// let valueInfo // Not enough information in sample for me to decode this object
}
struct Response: Decodable {
enum CodingKeys: String, CodingKey {
case date
case scanner = "Scanner"
}
let date: DateResponse
let scanner: Scanner
}
let decoder = JSONDecoder()
do {
let response = try decoder.decode(Response.self, from: data)
print(response)
} catch {
print("Error decoding: \(error.localizedDescription)")
}
Note: this example is very unforgiving. Any missing value or type that is not supported will lead to a DecodingError. It's up to you to determine all possible types and what is optional and what is not.
I also didn't decode everything nor do I handle the date object to it's fullest
This is as json goes a very complex example. Everything in it is polymorphic: the date, the Scanner, the ScannerDetails, etc. You need to be very careful how you decode this and make sure you handle all possibilities. I would suggest that if you're starting out, you should explore simpler examples.
I also chose to use enums. Not something everyone would chose but its my preference for decoding polymorphic types such as these.
You can read my article about dealing with polymorphic types as well as unknown types here: https://medium.com/#jacob.sikorski/awesome-uses-of-swift-enums-2ff011a3b5a5
I have this Json:
{ "first": {
"house": [
"small"
]
}, "second": {
"house": [
"small"
] }, "third": {
"car": [
"fast",
"economic"
] }, "fourth": {
"car": [
"fast",
"economic"
] }, "fifth": {
"car": [
"fast",
"economic"
],
"ice": [
"round",
"tasty"
],
"tree": [
"big",
"small"
] } }
I tried to set up a structure with Decodable but I do not get it to work:
struct secondLayer: Codable {
let exchange: [String: [String]]
}
struct decodeJson: Codable {
let symbol: [String: [secondLayer]]
static func decode(jsonString: String) - [decodeJson] {
var output = [decodeJson]()
let decode = JSONDecoder()
do {
let json = jsonString.data(using: .utf8)
output = try! decode.decode([decodeJson].self, from: json!)
} catch {
print(error.localizedDescription)
}
return output
}
}
I get this Error:
Fatal error: 'try!' expression unexpectedly raised an error:
Swift.DecodingError.typeMismatch(Swift.Array<Any>,
Swift.DecodingError.Context(codingPath: [], debugDescription:
"Expected to decode Array<Any but found a dictionary instead.",
underlyingError: nil)): file
/BuildRoot/Library/Caches/com.apple.xbs/Sources/swiftlang/swiftlang-900.0.74.1/src/swift/stdlib/public/core/ErrorType.swift,
line 181
I tried some modification but I do not get it to work.
The error message
"Expected to decode Array<Any> but found a dictionary instead."
is very clear. You want to decode an array ([decodeJson]) but the root object is a dictionary (starting with {)
Your code cannot work anyway. There are no keys exchange and symbol in the JSON.
Basically there are two ways to decode that JSON:
If all keys are dynamic you cannot decode the JSON to structs. You have to decode it to [String:[String:[String]]]. In this case Codable has no benefit over traditional JSONSerialization.
struct DecodeJson: Codable {
static func decode(jsonString: String) -> [String:[String:[String]]] {
var output = [String:[String:[String]]]()
let decoder = JSONDecoder()
do {
let json = Data(jsonString.utf8)
output = try decoder.decode([String:[String:[String]]].self, from: json)
print(output)
} catch {
print(error.localizedDescription)
}
return output
}
}
Or if the ordinal keys first, second etc are static use an umbrella struct
struct Root : Codable {
let first : [String:[String]]
let second : [String:[String]]
let third : [String:[String]]
let fourth : [String:[String]]
let fifth : [String:[String]]
}
struct DecodeJson {
static func decode(jsonString: String) -> Root? {
let decoder = JSONDecoder()
do {
let json = Data(jsonString.utf8)
let output = try decoder.decode(Root.self, from: json)
return output
} catch {
print(error.localizedDescription)
return nil
}
}
}
Of course you can decode house, car etc into a struct but this requires a custom initializer for each struct because you have to decode a single array manually with unkeyedContainer
I was trying to post the following jSON body
request JSON :
let parameters = [
"createTransactionRequest": [
"merchantAuthentication": [
"name": "xxxxxxxx",
"transactionKey": "xxxxxxxxx"
],
"refId": "123456",
"transactionRequest": [
"transactionType": "authCaptureTransaction",
"amount": "5",
"payment": [
"opaqueData": [
"dataDescriptor": desc!,
"dataValue": tocken!
]
]
]
]
]
When I am trying to print(parameters) the order of node changes it looks like
["createTransactionRequest":
["refId": "123456",
"transactionRequest":
["payment": ["opaqueData": ["dataDescriptor": "COMMON.ACCEPT.INAPP.PAYMENT", "dataValue": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx="]],
"transactionType": "authCaptureTransaction",
"amount": "5"],
"merchantAuthentication": ["name": "xxxxxxx", "transactionKey":
"6gvE46G5seZt563w"]
]
]
I am getting response like
{ messages = {
message = (
{
code = E00003;
text = "The element 'createTransactionRequest' in namespace
'AnetApi/xml/v1/schema/AnetApiSchema.xsd' has invalid child element
'refId' in namespace 'AnetApi/xml/v1/schema/AnetApiSchema.xsd'. List of
possible elements expected: 'merchantAuthentication' in namespace
'AnetApi/xml/v1/schema/AnetApiSchema.xsd'.";
}
);
resultCode = Error;
};
}
This is really annoying. anyones help will be highly grateful.
You need to change your data structure as follow:
struct Transaction: Codable {
let createTransactionRequest: CreateTransactionRequest
}
struct CreateTransactionRequest: Codable {
let merchantAuthentication: MerchantAuthentication
let refId: String
let transactionRequest: TransactionRequest
}
struct MerchantAuthentication: Codable {
let name: String
let transactionKey: String
}
struct TransactionRequest: Codable {
let transactionType: String
let amount: String
let payment: Payment
}
struct Payment: Codable {
let opaqueData: OpaqueData
}
struct OpaqueData: Codable {
let dataDescriptor: String
let dataValue: String
}
Testing
let json = """
{ "createTransactionRequest":
{ "merchantAuthentication":
{ "name": "YOUR_API_LOGIN_ID",
"transactionKey": "YOUR_TRANSACTION_KEY"
},
"refId": "123456",
"transactionRequest":
{ "transactionType": "authCaptureTransaction",
"amount": "5",
"payment":
{ "opaqueData":
{ "dataDescriptor": "COMMON.ACCEPT.INAPP.PAYMENT",
"dataValue": "PAYMENT_NONCE_GOES_HERE"
}
}
}
}
}
"""
let jsonData = Data(json.utf8)
do {
let transaction = try JSONDecoder().decode(Transaction.self, from: jsonData)
print(transaction)
// encoding
let encodedData = try JSONEncoder().encode(transaction)
print(String(data: encodedData, encoding: .utf8)!)
} catch {
print(error)
}
{"createTransactionRequest":{"merchantAuthentication":{"name":"YOUR_API_LOGIN_ID","transactionKey":"YOUR_TRANSACTION_KEY"},"refId":"123456","transactionRequest":{"transactionType":"authCaptureTransaction","amount":"5","payment":{"opaqueData":{"dataValue":"PAYMENT_NONCE_GOES_HERE","dataDescriptor":"COMMON.ACCEPT.INAPP.PAYMENT"}}}}}
I apologise if the title is unclear. I am not quite sure how exactly NSDictionary and JSON works.
I am trying to make a simple app using Swift that takes values from a .JSON file, and prints them out to the console. Here is my JSON file:
{
"students": [
{
"name": "Stew Dent",
"age": "10",
"year": 6,
"grades": [
{
"english": "a-plus",
"math": "b-plus"
},
{
"english": "a",
"math": "a-minus"
}
]
},
{
"name": "Mary Brown",
"age": "14",
"year": 10,
"grades": [
{
"english": "a-plus",
"math": "a-plus"
},
{
"english": "a-plus",
"math": "a"
}
]
}
]
}
Currently, I am able to retrieve the values of everything except the values in "grades". Here is my Swift code:
if let path = Bundle.main.path(forResource: "school", ofType: "json")
{
do {
// Retrieve data from JSON file
let jsonData = try NSData(contentsOfFile: path, options: .mappedIfSafe)
// Convert data into NSDictionary
let jsonResult = try JSONSerialization.jsonObject(with: jsonData as Data, options: JSONSerialization.ReadingOptions.mutableContainers) as? NSDictionary
if let students : [NSDictionary] = jsonResult?["students"] as? [NSDictionary]
{
if let grades : [NSDictionary] = students["grades"] as? [NSDictionary]
{
for grade: NSDictionary in grades
{
for (subject, gradevalue) in grade
{
print ("\(subject): \(gradevalue)")
}
}
}
}
} catch
{
}
}
If I am not wrong, the "grades" is a dictionary inside the "students" dictionary. However, it fails to run the above code. On the "if let grades..." line, it gives the error message: "Cannot subscript a value of type '[NSDictionary]' with an index type of 'String'.
So what I am I doing wrong? Is there even any way to retrieve those values? Am I missing something? Any help would be greatly appreciated. Thanks :)
You should use Swift native types Data instead of NSData and Dictionary [String:Any] instead of NSDictionary. You also forgot to iterate through each student. Try like this:
do {
if let dict = try JSONSerialization.jsonObject(with: jsonData) as? [String: Any] {
print(dict)
if let students = dict["students"] as? [[String: Any]] {
print(students)
for student in students {
print(student["name"] ?? "")
if let grades = student["grades"] as? [[String: Any]] {
for grade in grades {
for (subject, gradevalue) in grade {
print ("student:",student["name"] ?? "", "subject:", subject, "grade:", gradevalue)
}
}
}
}
}
}
} catch {
print(error)
}
Try this code, this should work looking at what you are trying to do
if let path = Bundle.main.path(forResource: "student", ofType: "json")
{
do {
// Retrieve data from JSON file
let jsonData = try NSData(contentsOfFile: path, options: .mappedIfSafe)
// Convert data into NSDictionary
let jsonResult = try JSONSerialization.jsonObject(with: jsonData as Data, options: JSONSerialization.ReadingOptions.mutableContainers) as? NSDictionary
if let students = jsonResult?["students"] as? [NSDictionary]
{
for student in students
{
for grades in student["grades"] as! [[String:String]]{
for eachGrade in grades{
print("\(eachGrade.key) : \(eachGrade.value)")
}
}
}
}
}
catch
{
}
}