I have a rather complex structure to encode in order to pass it with the body of my post.
case .sendData(let parameters):
urlRequest = try Alamofire.JSONEncoding.default.encode(urlRequest, withJSONObject: parameters.encode())
parameters is not of the [String:Any] type, but of the type 'QuestionnaireAnswers' which is a struct. So I need to create the encode functions. I tried the code below but it fails
struct ItemResponse {
let question: String
let answerArray: [String]
}
// MARK: Encodable
extension ItemResponse {
func encode() -> [String: Any] {
return [
"question": question,
"answerArray": answerArray
]
}
}
struct QuestionnaireAnswers{
let version: Int
var answers: [ItemResponse]
}
// MARK: Encodable
extension QuestionnaireAnswers {
func encode() -> [String: Any] {
return [
"version": version,
"answers": answers
]
}
}
In the end, the JSON should look like this :
{
version: 1,
answers: [
{ question: 'dog', answerArray: ['yay'] },
{ question: 'cat', answerArray: ['< 500'] },
{ question: 'tree', answerArray: ['sorry', 'OK then','NotWorking'] },
],
}
Related
I have geoJSON file:
{
"type": "Feature",
"geometry": {
"type": "MultiPolygon",
"coordinates": [
[
[
[
40.303141,
55.9765684
],
[
40.3033449,
55.9765114
],
[
40.3034017,
55.976575
],
[
40.3031979,
55.9766321
],
[
40.303141,
55.9765684
]
]
]
]
},
"properties": {
"#id": 4305947573,
"building": "yes"
}
}
I'm interested in properties:
"properties":{"#id":4305947573,"building":"yes"}
I want parse "properties", and make structure:
struct Feature: Decodable {
let type: String
let properties: Dictionary<String, String> }
It's work good, but then i add parameter in geoJSON: "#id":4305947573
4305947573 - this is Int variable, and parser don't parse geoJSON.
I think i need modify my struct Feature. I want to parser understand and String, and Int in properties.
Help me please. Thank you
There are a number of GeoJSON swift libraries (search github) that you could use
instead of re-inventing the wheel.
If you really want to code it yourself, try this approach,
where the dynamic keys and values of properties are decoded
into a dictionary of var data: [String: Any], as shown.
Use the struct models like this:
let result = try JSONDecoder().decode(Feature.self, from: data)
Models
struct Feature: Decodable {
let type: String
var properties: Properties
// ...
}
struct Properties: Decodable {
var data: [String: Any] = [:]
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: DynamicKey.self)
container.allKeys.forEach { key in
if let theString = try? container.decode(String.self, forKey: key) {
self.data[key.stringValue] = theString
}
if let theInt = try? container.decode(Int.self, forKey: key) {
self.data[key.stringValue] = theInt
}
}
}
}
struct DynamicKey: CodingKey {
var intValue: Int?
init?(intValue: Int) {
self.intValue = intValue
self.stringValue = ""
}
var stringValue: String
init?(stringValue: String) {
self.stringValue = stringValue
self.intValue = nil
}
}
I am new to iOS, and want to parse the JSON using Decodable but cant get through this, how should I work this out?
The view controller where I am trying to parse the data
class ViewController: UIViewController {
var servers = [Server]()
let apiUrl = "https://someurl/api/dashboard"
override func viewDidLoad() {
super.viewDidLoad()
guard let url = URL(string: self.apiUrl) else { return }
getDataFrom(url)
}
fileprivate func getDataFrom(_ url: URL) {
URLSession.shared.dataTask(with: url){ (data, response, error) in
guard let data = data else { return }
do {
let apiResponse = try JSONDecoder().decode(Server.self, from: data)
print(apiResponse)
} catch let jsonError {
print(jsonError)
}
}.resume()
}
}
The Server.swift file where I am confirming to the decodable protocol
struct Server: Decodable {
let current_page: Int
let data: [ServerData]
let first_page_url: String
}
struct ServerData: Decodable {
let hostname: String
let ipaddress: String
let customer: [Customer]
let latest_value: [LatestValue]
}
struct Customer: Decodable {
let name: String
let contact_person :String
let email: String
}
struct LatestValue: Decodable {
let systemuptime: String
let memtotal: Float
let memfree: Double
let loadaverage: Float
}
No value associated with key CodingKeys I get this error,
The response from the server
{
"servers": {
"current_page": 1,
"data": [
{
"hostname": "johndoes",
"ipaddress": "10.0.2.99",
"id": 7,
"latest_value_id": 1130238,
"customers": [
{
"name": "Jane Doe",
"contact_person": "John Doe",
"id": 2,
"email": "john.#example.com",
"pivot": {
"server_id": 7,
"customer_id": 2
}
}
],
"latest_value": {
"id": 1130238,
"server_id": 7,
"systemuptime": "80days:10hours:23minutes",
"memtotal": 3.7,
"memfree": 1.6400000000000001,
"loadaverage": 2.25,
"disktotal": {
"dev-mapper-centos-root_disktotal": "38",
"dev-mapper-proquote-xfs-lvm_disktotal": "200"
},
"diskused": "{\"dev-mapper-centos-root_diskused\":\"16\",\"dev-mapper-proquote-xfs-lvm_diskused\":\"188\"}",
"custom_field": "[]",
"additional_attributes": {
"fathom": {
"name": "fathom",
"status": 1
},
"trenddb": {
"name": "trenddb",
"status": 1
},
"trendwi": {
"name": "trendwi",
"status": 1
},
"appsrv": {
"name": "appsrv",
"status": 1
}
},
"created_at": "2019-06-15 02:25:02",
"updated_at": "2019-06-15 02:25:02"
}
}
]
},
"message": "Success"
}
You seem to have few different errors in your data structure.
First of all, you are trying to decode Server while your json has servers inside a dict {"servers": ... }, So use a parent root object for it.
Your latest_value inside ServerData is defined as array, while it should be LatestValue struct not [LatestValue].
There is no first_page_url element in your json, but your Server struct has the property, make it optional, so that JSONDecoder decodes it only if it is present.
Here is your refined data models.
struct Response: Decodable {
let servers: Server
}
struct Server: Decodable {
let current_page: Int
let data: [ServerData]
let first_page_url: String?
}
struct ServerData: Decodable {
let hostname: String
let ipaddress: String
let customers: [Customer]
let latest_value: LatestValue
}
struct Customer: Decodable {
let name: String
let contact_person :String
let email: String
}
struct LatestValue: Decodable {
let systemuptime: String
let memtotal: Float
let memfree: Double
let loadaverage: Float
}
And decode Response instead of decoding Server, like so,
do {
let apiResponse = try JSONDecoder().decode(Response.self, from: data)
let server = apiResponse.server // Here is your server struct.
print(server)
} catch let jsonError {
print(jsonError)
}
I have a following struct with generics for API response with pagination:
struct Paginable<Body> {
let data: [Body]
let meta: Meta
}
extension Paginable {
struct Meta: Codable {
let pagination: Pagination
struct Pagination: Codable {
let total: Int
let count: Int
let perPage: Int
let currentPage: Int
let totalPages: Int
}
}
}
And I want to be able to decode it like so:
let response = try? response.decode(to: Paginable<Segment>.self)
So here's my attempt to make it Decodable:
extension Paginable where Body == Data {
func decode<BodyType: Decodable>(to type: BodyType.Type) throws -> Paginable<BodyType> {
guard let decodedJSON = try? JSONDecoder().decode(BodyType.self, from: data) else {
throw APIError.decodingFailure
}
return Paginable<BodyType>(data: decodedJSON, meta: self.meta)
}
}
This gives me two errors:
Cannot convert value of type 'Paginable.Meta' to expected argument type 'Paginable<_>.Meta'
on the line with return statement
If I change the meta property to some primitive type like Int, the error disappears. But Meta itself is Codable, so what's to problem here?
Cannot convert value of type '[Data]' to expected argument type 'Data'
on the line with guard statement
How to solve this one?
You need to conform Paginable to Codable like,
struct Paginable<Body>: Codable where Body: Codable {
let data: [Body]
let meta: Meta
}
Change decode(data:to:) method in extension Paginable to,
extension Paginable {
static func decode<BodyType: Decodable>(data: Data, to type: BodyType.Type) throws -> BodyType? {
do {
let response = try JSONDecoder().decode(BodyType.self, from: data)
return response
} catch {
throw error
}
}
}
Usage:
if let data = str.data(using: .utf8) {
do {
let response = try Paginable<Segment>.decode(data: data, to: Paginable<Segment>.self)
print(response)
} catch {
print(error)
}
}
Edit:
JSON format:
{
"data": [
{
"name": "Name-1"
},
{
"name": "Name-2"
}
],
"meta": {
"pagination": {
"total": 100,
"count": 10,
"perPage": 5,
"currentPage": 1,
"totalPages": 10
}
}
}
Can someone tell me what I'm doing wrong? I've looked at all the questions on here like from here How to decode a nested JSON struct with Swift Decodable protocol? and I've found one that seems exactly what I need Swift 4 Codable decoding json.
{
"success": true,
"message": "got the locations!",
"data": {
"LocationList": [
{
"LocID": 1,
"LocName": "Downtown"
},
{
"LocID": 2,
"LocName": "Uptown"
},
{
"LocID": 3,
"LocName": "Midtown"
}
]
}
}
struct Location: Codable {
var data: [LocationList]
}
struct LocationList: Codable {
var LocID: Int!
var LocName: String!
}
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let url = URL(string: "/getlocationlist")
let task = URLSession.shared.dataTask(with: url!) { data, response, error in
guard error == nil else {
print(error!)
return
}
guard let data = data else {
print("Data is empty")
return
}
do {
let locList = try JSONDecoder().decode(Location.self, from: data)
print(locList)
} catch let error {
print(error)
}
}
task.resume()
}
The error I am getting is:
typeMismatch(Swift.Array, Swift.DecodingError.Context(codingPath:
[], debugDescription: "Expected to decode Array but found a
dictionary instead.", underlyingError: nil))
Check the outlined structure of your JSON text:
{
"success": true,
"message": "got the locations!",
"data": {
...
}
}
The value for "data" is a JSON object {...}, it is not an array.
And the structure of the object:
{
"LocationList": [
...
]
}
The object has a single entry "LocationList": [...] and its value is an array [...].
You may need one more struct:
struct Location: Codable {
var data: LocationData
}
struct LocationData: Codable {
var LocationList: [LocationItem]
}
struct LocationItem: Codable {
var LocID: Int!
var LocName: String!
}
For testing...
var jsonText = """
{
"success": true,
"message": "got the locations!",
"data": {
"LocationList": [
{
"LocID": 1,
"LocName": "Downtown"
},
{
"LocID": 2,
"LocName": "Uptown"
},
{
"LocID": 3,
"LocName": "Midtown"
}
]
}
}
"""
let data = jsonText.data(using: .utf8)!
do {
let locList = try JSONDecoder().decode(Location.self, from: data)
print(locList)
} catch let error {
print(error)
}
After searching lots of thing internet, I certainly figured out this is the sweetest way to print well formatted json from any object.
let jsonString = object.toJSONString(prettyPrint: true)
print(jsonString as AnyObject)
Apple documentation about JSONEncoder ->
struct GroceryProduct: Codable {
var name: String
var points: Int
var description: String?
}
let pear = GroceryProduct(name: "Pear", points: 250, description: "A ripe pear.")
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
let data = try encoder.encode(pear)
print(String(data: data, encoding: .utf8)!)
/* Prints:
{
"name" : "Pear",
"points" : 250,
"description" : "A ripe pear."
}
*/
I'm trying to implement the new Codable protocol, so I added Codable to my struct, but am stuck on decoding the JSON.
Here's what I had before:
Struct -
struct Question {
var title: String
var answer: Int
var question: Int
}
Client -
...
guard let data = data else {
return
}
do {
self.jsonResponse = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String: Any]
let questionItems = self.jsonResponse?["themes"] as! [[String: Any]]
questionItems.forEach {
let item = Question(title: $0["title"] as! String,
answer: $0["answer"] as! Int,
question: $0["question"] as! Int)
questionData.append(item)
}
} catch {
print("error")
}
Here's what I have now, except I can't figure out the decoder part:
Struct -
struct Question: Codable {
var title: String
var answer: Int
var question: Int
}
Client -
...
let decoder = JSONDecoder()
if let questions = try? decoder.decode([Question].self, from: data) {
// Can't get past this part
} else {
print("Not working")
}
It prints "Not working" because I can't get past the decoder.decode part. Any ideas? Will post any extra code as needed, thanks!
EDIT:
Sample of API JSON:
{
"themes": [
{
"answer": 1,
"question": 44438222,
"title": "How many letters are in the alphabet?"
},
{
"answer": 0,
"question": 44438489,
"title": "This is a random question"
}
]
}
If I print self.jsonResponse I get this:
Optional(["themes": <__NSArrayI 0x6180002478f0>(
{
"answer" = 7;
"question" = 7674790;
title = "This is the title of the question";
},
{
"answer_" = 2;
"question" = 23915741;
title = "This is the title of the question";
}
My new code:
struct Theme: Codable {
var themes : [Question]
}
struct Question: Codable {
var title: String
var answer: Int
var question: Int
}
...
if let decoded = try? JSONDecoder().decode(Theme.self, from: data) {
print("decoded:", decoded)
} else {
print("Not working")
}
If your JSON has a structure
{"themes" : [{"title": "Foo", "answer": 1, "question": 2},
{"title": "Bar", "answer": 3, "question": 4}]}
you need an equivalent for the themes object. Add this struct
struct Theme : Codable {
var themes : [Question]
}
Now you can decode the JSON:
if let decoded = try? JSONDecoder().decode(Theme.self, from: data) {
print("decoded:", decoded)
} else {
print("Not working")
}
The containing Question objects are decoded implicitly.
You're getting this error because your JSON is likely structured as so:
{
"themes": [
{ "title": ..., "question": ..., "answer": ... },
{ "title": ..., "question": ..., "answer": ... },
{ ... }
],
...
}
However, the code you wrote expects a [Question] at the top level. What you need is a different top-level type that has a themes property which is a [Question]. When you decode that top-level type, your [Question] will be decoded for the themes key.
Hello #all I have added the code for JSON Encoding and Decoding for Swift 4.
Please use the link here