I have a json like bellow:
object{2}
status: 1
result{3}
cohorts[23]
categories[158]
languages[16]
And I am Decoder it like bellow:
struct ResultAPIJSON: Decodable {
private enum RootCodingKeys: String, CodingKey {
case result
}
private enum FeatureCohortsCodingKeys: String, CodingKey {
case cohorts
}
var cohortsPropertiesArray = [CohortsProperties]()
init(from decoder: Decoder) throws {
let rootContainerCohorts = try decoder.container(keyedBy: RootCodingKeys.self)
var featuresContainerCohorts = try rootContainerCohorts.nestedUnkeyedContainer(forKey: .result)
let AAA = try featuresContainerCohorts.nestedContainer(keyedBy: FeatureCohortsCodingKeys.self)
let BBB = try AAA.nestedUnkeyedContainer(forKey: .cohorts)
while BBB.isAtEnd == false {
let propertiesContainer = try featuresContainerCohorts.nestedContainer(keyedBy: FeatureCohortsCodingKeys.self)
// Decodes a single quake from the data, and appends it to the array.
let properties = try propertiesContainer.decode(CohortsProperties.self, forKey: .cohorts)
cohortsPropertiesArray.append(properties)
}
}
}
But get me bellow error:
typeMismatch(Swift.Array<Any>, Swift.DecodingError.Context(codingPath: [], debugDescription: "Expected to decode Array<Any> but found a dictionary instead.", underlyingError: nil))
If this is your JSON
object{2}
status: 1
result{3}
cohorts[23]
categories[158]
languages[16]
(or more likely, this:)
{
"status": 1,
"result": {
"cohorts": 23,
"categories": 158,
"languages": 16
}
}
then you need two structs:
struct object: Decodable {
let status: Int
let result: Result
}
struct Result: Decodable {
let cohorts: Int
let categories: Int
let languages: Int
}
I have JSON that looks like this:
{
success: true,
message: null,
messages: null,
data: [
[ ... ]
]
}
Now I am wondering, I can solve this with:
struct Something: Codable {
let data: [[Data]]
}
something.data.flatMap { $0 }
But I would rather do:
struct Something: Codable {
let data: [Data]
}
I already know I can achieve navigation through JSON with sets of CodingKeys enums and container.nestedContainer(...) but how do I achieve this when there's no key, but just an array in an array? Can I achieve this with the custom init on Decodable and if so, how?
A possible solution is to write a custom initializer for flattening the array
struct Root : Decodable {
let success : Bool
let data : [Foo]
private enum CodingKeys : String, CodingKey { case success, data }
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
success = try container.decode(Bool.self, forKey: .success)
let arrayData = try container.decode([[Foo]].self, forKey: .data)
guard !arrayData.isEmpty else { throw DecodingError.dataCorruptedError(forKey: .data, in: container, debugDescription: "Object is empty") }
data = arrayData.first!
}
}
struct Foo : Decodable { ... }
The type Data exists in the Foundation framework. You are strongly discouraged from using it as custom type.
How can I decode data to a structure using Alamofire and SwiftyJSON? My attempts give me errors like that
"No value associated with key CodingKeys(stringValue: \"user\",
intValue: nil)
Here is my code, my try doesn't give me the result when I use non-optional values, they respond to me with NIL values
Alamofire.request(url, method: .post, parameters: params, encoding: URLEncoding.default, headers: nil).responseJSON { (response) in
if response.data != nil {
switch response.result {
case.failure( let error):
print(error)
case.success(let val):
var json = JSON(val)
print(json)
guard let data = response.data else {return}
do {
let root = try JSONDecoder().decode(MainInfo.self, from: data)
print(root.submodel)
}
catch {
print("Bigerror")
print(error)
}
This is my structure
struct user: Codable {
var push_id:String?
var name:String?
var id:String?
var role_id:String?
var taxi_park_id:Int?
var car_number:String?
enum CodingKeys:String,CodingKey {
case push_id = "push_id"
case name = "name"
case id = "id"
case role_id = "role_id"
case taxi_park_id = "taxi_park_id"
case car_number = "car_number"
}
}
struct MainInfo : Decodable {
let model: String?
let submodel: String?
let user:user
enum CodingKeys:String,CodingKey {
case model = "model"
case submodel = "submodel"
case user = "user"
}
}
This is my pretty printed json
{
"facilities" : [
],
"model" : "AMC",
"taxi_park" : "Taxi +",
"submodel" : "Gremlin",
"user" : {
"role_id" : 2,
"push_id" : "dW7Cy-ItcDo:APA91bH62zJJKKz0t9VxP29H0iE2xhnQH0hDvKpGaHc5pknuTuZq2lMaj-EapQlN3O4dJF0ysSuCNOeb-2SdJaJaLIZcwHD3CCpeNpz6UVeGktoCm2ykL2rNXF5-ofQckvz1xTvVO0V6",
"taxi_park_id" : 0,
"id" : 3,
"name" : "China",
"car_number" : "X123OOO"
}
}
First of all your question has nothing to do with SwiftyJSON as you are using Codable.
Second of all name the structs with starting capital letter (User), that avoids confusion like let user : user
The error is misleading. All .._id values except push_id are Int rather than String. It's very easy to distinguish strings from all other types: Strings are always wrapped in double quotes.
And if you pass the convertFromSnakeCase key decoding strategy you don't need CodingKeys at all
struct MainInfo : Decodable {
let model : String
let submodel : String
let user : User
}
struct User: Decodable {
let pushId : String
let name : String
let id : Int
let roleId : Int
let taxiParkId : Int
let carNumber : String
}
...
do {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let root = try decoder.decode(MainInfo.self, from: data)
print(root.submodel)
} catch { print(error) }
Try this code, also a simple tip, we use coding keys in swift because sometimes we have to receive an inconvenient parameter keys but we also want to use it simple and clearly in the struct therefore CodingKeys are helpful in your case you using CodingKeys to decode the same parameter name i added the following taxiPark propriety to give you a hint on why they are useful, for example: i want to parse a JSON that have a key called
Person_ID_From_School
with coding keys i can do that with a better naming simple as personId and so on
struct MainInfo : Decodable {
let model: String?
let submodel: String?
let user:user
let taxiPark: String?
let facilities: [String?]?
enum CodingKeys:String,CodingKey {
case model = "model"
case submodel = "submodel"
case user = "user"
case taxiPark = "taxi_park"
case facilities = "facilities"
}
}
While using Swift4 and Codable protocols I got the following problem - it looks like there is no way to allow JSONDecoder to skip elements in an array.
For example, I have the following JSON:
[
{
"name": "Banana",
"points": 200,
"description": "A banana grown in Ecuador."
},
{
"name": "Orange"
}
]
And a Codable struct:
struct GroceryProduct: Codable {
var name: String
var points: Int
var description: String?
}
When decoding this json
let decoder = JSONDecoder()
let products = try decoder.decode([GroceryProduct].self, from: json)
Resulting products is empty. Which is to be expected, due to the fact that the second object in JSON has no "points" key, while points is not optional in GroceryProduct struct.
Question is how can I allow JSONDecoder to "skip" invalid object?
One option is to use a wrapper type that attempts to decode a given value; storing nil if unsuccessful:
struct FailableDecodable<Base : Decodable> : Decodable {
let base: Base?
init(from decoder: Decoder) throws {
let container = try decoder.singleValueContainer()
self.base = try? container.decode(Base.self)
}
}
We can then decode an array of these, with your GroceryProduct filling in the Base placeholder:
import Foundation
let json = """
[
{
"name": "Banana",
"points": 200,
"description": "A banana grown in Ecuador."
},
{
"name": "Orange"
}
]
""".data(using: .utf8)!
struct GroceryProduct : Codable {
var name: String
var points: Int
var description: String?
}
let products = try JSONDecoder()
.decode([FailableDecodable<GroceryProduct>].self, from: json)
.compactMap { $0.base } // .flatMap in Swift 4.0
print(products)
// [
// GroceryProduct(
// name: "Banana", points: 200,
// description: Optional("A banana grown in Ecuador.")
// )
// ]
We're then using .compactMap { $0.base } to filter out nil elements (those that threw an error on decoding).
This will create an intermediate array of [FailableDecodable<GroceryProduct>], which shouldn't be an issue; however if you wish to avoid it, you could always create another wrapper type that decodes and unwraps each element from an unkeyed container:
struct FailableCodableArray<Element : Codable> : Codable {
var elements: [Element]
init(from decoder: Decoder) throws {
var container = try decoder.unkeyedContainer()
var elements = [Element]()
if let count = container.count {
elements.reserveCapacity(count)
}
while !container.isAtEnd {
if let element = try container
.decode(FailableDecodable<Element>.self).base {
elements.append(element)
}
}
self.elements = elements
}
func encode(to encoder: Encoder) throws {
var container = encoder.singleValueContainer()
try container.encode(elements)
}
}
You would then decode as:
let products = try JSONDecoder()
.decode(FailableCodableArray<GroceryProduct>.self, from: json)
.elements
print(products)
// [
// GroceryProduct(
// name: "Banana", points: 200,
// description: Optional("A banana grown in Ecuador.")
// )
// ]
I would create a new type Throwable, which can wrap any type conforming to Decodable:
enum Throwable<T: Decodable>: Decodable {
case success(T)
case failure(Error)
init(from decoder: Decoder) throws {
do {
let decoded = try T(from: decoder)
self = .success(decoded)
} catch let error {
self = .failure(error)
}
}
}
For decoding an array of GroceryProduct (or any other Collection):
let decoder = JSONDecoder()
let throwables = try decoder.decode([Throwable<GroceryProduct>].self, from: json)
let products = throwables.compactMap { $0.value }
where value is a computed property introduced in an extension on Throwable:
extension Throwable {
var value: T? {
switch self {
case .failure(_):
return nil
case .success(let value):
return value
}
}
}
I would opt for using a enum wrapper type (over a Struct) because it may be useful to keep track of the errors that are thrown as well as their indices.
Swift 5
For Swift 5 Consider using the Result enum e.g.
struct Throwable<T: Decodable>: Decodable {
let result: Result<T, Error>
init(from decoder: Decoder) throws {
result = Result(catching: { try T(from: decoder) })
}
}
To unwrap the decoded value use the get() method on the result property:
let products = throwables.compactMap { try? $0.result.get() }
The problem is that when iterating over a container, the container.currentIndex isn’t incremented so you can try to decode again with a different type.
Because the currentIndex is read only, a solution is to increment it yourself successfully decoding a dummy. I took #Hamish solution, and wrote a wrapper with a custom init.
This problem is a current Swift bug: https://bugs.swift.org/browse/SR-5953
The solution posted here is a workaround in one of the comments.
I like this option because I’m parsing a bunch of models the same way on a network client, and I wanted the solution to be local to one of the objects. That is, I still want the others to be discarded.
I explain better in my github https://github.com/phynet/Lossy-array-decode-swift4
import Foundation
let json = """
[
{
"name": "Banana",
"points": 200,
"description": "A banana grown in Ecuador."
},
{
"name": "Orange"
}
]
""".data(using: .utf8)!
private struct DummyCodable: Codable {}
struct Groceries: Codable
{
var groceries: [GroceryProduct]
init(from decoder: Decoder) throws {
var groceries = [GroceryProduct]()
var container = try decoder.unkeyedContainer()
while !container.isAtEnd {
if let route = try? container.decode(GroceryProduct.self) {
groceries.append(route)
} else {
_ = try? container.decode(DummyCodable.self) // <-- TRICK
}
}
self.groceries = groceries
}
}
struct GroceryProduct: Codable {
var name: String
var points: Int
var description: String?
}
let products = try JSONDecoder().decode(Groceries.self, from: json)
print(products)
There are two options:
Declare all members of the struct as optional whose keys can be missing
struct GroceryProduct: Codable {
var name: String
var points : Int?
var description: String?
}
Write a custom initializer to assign default values in the nil case.
struct GroceryProduct: Codable {
var name: String
var points : Int
var description: String
init(from decoder: Decoder) throws {
let values = try decoder.container(keyedBy: CodingKeys.self)
name = try values.decode(String.self, forKey: .name)
points = try values.decodeIfPresent(Int.self, forKey: .points) ?? 0
description = try values.decodeIfPresent(String.self, forKey: .description) ?? ""
}
}
A solution made possible by Swift 5.1, using the property wrapper:
#propertyWrapper
struct IgnoreFailure<Value: Decodable>: Decodable {
var wrappedValue: [Value] = []
private struct _None: Decodable {}
init(from decoder: Decoder) throws {
var container = try decoder.unkeyedContainer()
while !container.isAtEnd {
if let decoded = try? container.decode(Value.self) {
wrappedValue.append(decoded)
}
else {
// item is silently ignored.
try? container.decode(_None.self)
}
}
}
}
And then the usage:
let json = """
{
"products": [
{
"name": "Banana",
"points": 200,
"description": "A banana grown in Ecuador."
},
{
"name": "Orange"
}
]
}
""".data(using: .utf8)!
struct GroceryProduct: Decodable {
var name: String
var points: Int
var description: String?
}
struct ProductResponse: Decodable {
#IgnoreFailure
var products: [GroceryProduct]
}
let response = try! JSONDecoder().decode(ProductResponse.self, from: json)
print(response.products) // Only contains banana.
Note: The property wrapper things will only works if the response can be wrapped in a struct (i.e: not a top level array).
In that case, you can still wrap it manually (with a typealias for better readability):
typealias ArrayIgnoringFailure<Value: Decodable> = IgnoreFailure<Value>
let response = try! JSONDecoder().decode(ArrayIgnoringFailure<GroceryProduct>.self, from: json)
print(response.wrappedValue) // Only contains banana.
Ive put #sophy-swicz solution, with some modifications, into an easy to use extension
fileprivate struct DummyCodable: Codable {}
extension UnkeyedDecodingContainer {
public mutating func decodeArray<T>(_ type: T.Type) throws -> [T] where T : Decodable {
var array = [T]()
while !self.isAtEnd {
do {
let item = try self.decode(T.self)
array.append(item)
} catch let error {
print("error: \(error)")
// hack to increment currentIndex
_ = try self.decode(DummyCodable.self)
}
}
return array
}
}
extension KeyedDecodingContainerProtocol {
public func decodeArray<T>(_ type: T.Type, forKey key: Self.Key) throws -> [T] where T : Decodable {
var unkeyedContainer = try self.nestedUnkeyedContainer(forKey: key)
return try unkeyedContainer.decodeArray(type)
}
}
Just call it like this
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
self.items = try container.decodeArray(ItemType.self, forKey: . items)
}
For the example above:
let json = """
[
{
"name": "Banana",
"points": 200,
"description": "A banana grown in Ecuador."
},
{
"name": "Orange"
}
]
""".data(using: .utf8)!
struct Groceries: Codable
{
var groceries: [GroceryProduct]
init(from decoder: Decoder) throws {
var container = try decoder.unkeyedContainer()
groceries = try container.decodeArray(GroceryProduct.self)
}
}
struct GroceryProduct: Codable {
var name: String
var points: Int
var description: String?
}
let products = try JSONDecoder().decode(Groceries.self, from: json)
print(products)
Instead, You can also do like this:
struct GroceryProduct: Decodable {
var name: String
var points: Int
var description: String?
}'
and then in while getting it:
'let groceryList = try JSONDecoder().decode(Array<GroceryProduct>.self, from: responseData)'
Unfortunately Swift 4 API doesn't have failable initializer for init(from: Decoder).
Only one solution that I see is implementing custom decoding, giving default value for optional fields and possible filter with needed data:
struct GroceryProduct: Codable {
let name: String
let points: Int?
let description: String
private enum CodingKeys: String, CodingKey {
case name, points, description
}
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
name = try container.decode(String.self, forKey: .name)
points = try? container.decode(Int.self, forKey: .points)
description = (try? container.decode(String.self, forKey: .description)) ?? "No description"
}
}
// for test
let dict = [["name": "Banana", "points": 100], ["name": "Nut", "description": "Woof"]]
if let data = try? JSONSerialization.data(withJSONObject: dict, options: []) {
let decoder = JSONDecoder()
let result = try? decoder.decode([GroceryProduct].self, from: data)
print("rawResult: \(result)")
let clearedResult = result?.filter { $0.points != nil }
print("clearedResult: \(clearedResult)")
}
I improved on #Hamish's for the case, that you want this behaviour for all arrays:
private struct OptionalContainer<Base: Codable>: Codable {
let base: Base?
init(from decoder: Decoder) throws {
let container = try decoder.singleValueContainer()
base = try? container.decode(Base.self)
}
}
private struct OptionalArray<Base: Codable>: Codable {
let result: [Base]
init(from decoder: Decoder) throws {
let container = try decoder.singleValueContainer()
let tmp = try container.decode([OptionalContainer<Base>].self)
result = tmp.compactMap { $0.base }
}
}
extension Array where Element: Codable {
init(from decoder: Decoder) throws {
let optionalArray = try OptionalArray<Element>(from: decoder)
self = optionalArray.result
}
}
Swift 5
Inspired with previous answers I decode inside Result enum extension.
What do you think about it?
extension Result: Decodable where Success: Decodable, Failure == DecodingError {
public init(from decoder: Decoder) throws {
let container: SingleValueDecodingContainer = try decoder.singleValueContainer()
do {
self = .success(try container.decode(Success.self))
} catch {
if let decodingError = error as? DecodingError {
self = .failure(decodingError)
} else {
self = .failure(DecodingError.dataCorrupted(.init(codingPath: [], debugDescription: error.localizedDescription)))
}
}
}
}
Usage
let listResult = try? JSONDecoder().decode([Result<SomeObject, DecodingError>].self, from: ##YOUR DATA##)
let list: [SomeObject] = listResult.compactMap {try? $0.get()}
#Hamish's answer is great. However, you can reduce FailableCodableArray to:
struct FailableCodableArray<Element : Codable> : Codable {
var elements: [Element]
init(from decoder: Decoder) throws {
let container = try decoder.singleValueContainer()
let elements = try container.decode([FailableDecodable<Element>].self)
self.elements = elements.compactMap { $0.wrapped }
}
func encode(to encoder: Encoder) throws {
var container = encoder.singleValueContainer()
try container.encode(elements)
}
}
I had a similar issue recently, but slightly different.
struct Person: Codable {
var name: String
var age: Int
var description: String?
var friendnamesArray:[String]?
}
In this case, if one of the element in friendnamesArray is nil, the whole object is nil while decoding.
And the right way to handle this edge case is to declare the string array[String] as array of optional strings[String?] as below,
struct Person: Codable {
var name: String
var age: Int
var description: String?
var friendnamesArray:[String?]?
}
You made the description optional, you should also make the points field optional if there is a chance it could be nil, such as this:
struct GroceryProduct: Codable {
var name: String
var points: Int?
var description: String?
}
Just make sure you safe-unwrap it however you see fit for it's use. I'm guessing nil points == 0 in the actual use case so an example could be:
let products = try JSONDecoder().decode([GroceryProduct].self, from: json)
for product in products {
let name = product.name
let points = product.points ?? 0
let description = product.description ?? ""
ProductView(name, points, description)
}
or in-line:
let products = try JSONDecoder().decode([GroceryProduct].self, from: json)
for product in products {
ProductView(product.name, product.points ?? 0, product.description ?? "")
}
I come up with this KeyedDecodingContainer.safelyDecodeArray that provides a simple interface:
extension KeyedDecodingContainer {
/// The sole purpose of this `EmptyDecodable` is allowing decoder to skip an element that cannot be decoded.
private struct EmptyDecodable: Decodable {}
/// Return successfully decoded elements even if some of the element fails to decode.
func safelyDecodeArray<T: Decodable>(of type: T.Type, forKey key: KeyedDecodingContainer.Key) -> [T] {
guard var container = try? nestedUnkeyedContainer(forKey: key) else {
return []
}
var elements = [T]()
elements.reserveCapacity(container.count ?? 0)
while !container.isAtEnd {
/*
Note:
When decoding an element fails, the decoder does not move on the next element upon failure, so that we can retry the same element again
by other means. However, this behavior potentially keeps `while !container.isAtEnd` looping forever, and Apple does not offer a `.skipFailable`
decoder option yet. As a result, `catch` needs to manually skip the failed element by decoding it into an `EmptyDecodable` that always succeed.
See the Swift ticket https://bugs.swift.org/browse/SR-5953.
*/
do {
elements.append(try container.decode(T.self))
} catch {
if let decodingError = error as? DecodingError {
Logger.error("\(#function): skipping one element: \(decodingError)")
} else {
Logger.error("\(#function): skipping one element: \(error)")
}
_ = try? container.decode(EmptyDecodable.self) // skip the current element by decoding it into an empty `Decodable`
}
}
return elements
}
}
The potentially infinite loop while !container.isAtEnd is a concern, and it's addressed by using EmptyDecodable.
A much simpler attempt:
Why don't you declare points as optional or make the array contain optional elements
let products = [GroceryProduct?]
Features:
Simple use. One line in Decodable instance: let array: CompactDecodableArray<Int>
Is decoded with standard mapping mechanism: JSONDecoder().decode(Model.self, from: data)
skips incorrect elements (returns array with only successful mapped elements)
Details
Xcode 12.1 (12A7403)
Swift 5.3
Solution
class CompactDecodableArray<Element>: Decodable where Element: Decodable {
private(set) var elements = [Element]()
required init(from decoder: Decoder) throws {
guard var unkeyedContainer = try? decoder.unkeyedContainer() else { return }
while !unkeyedContainer.isAtEnd {
if let value = try? unkeyedContainer.decode(Element.self) {
elements.append(value)
} else {
unkeyedContainer.skip()
}
}
}
}
// https://forums.swift.org/t/pitch-unkeyeddecodingcontainer-movenext-to-skip-items-in-deserialization/22151/17
struct Empty: Decodable { }
extension UnkeyedDecodingContainer {
mutating func skip() { _ = try? decode(Empty.self) }
}
Usage
struct Model2: Decodable {
let num: Int
let str: String
}
struct Model: Decodable {
let num: Int
let str: String
let array1: CompactDecodableArray<Int>
let array2: CompactDecodableArray<Int>?
let array4: CompactDecodableArray<Model2>
}
let dictionary: [String : Any] = ["num": 1, "str": "blablabla",
"array1": [1,2,3],
"array3": [1,nil,3],
"array4": [["num": 1, "str": "a"], ["num": 2]]
]
let data = try! JSONSerialization.data(withJSONObject: dictionary)
let object = try JSONDecoder().decode(Model.self, from: data)
print("1. \(object.array1.elements)")
print("2. \(object.array2?.elements)")
print("3. \(object.array4.elements)")
Console
1. [1, 2, 3]
2. nil
3. [__lldb_expr_25.Model2(num: 1, str: "a")]
JSON to decode:
{
"jsonrpc": "2.0",
"result": [
{
"code": 1,
"message": "error"
},
[
{
"gid": "123"
....
}
]
....
]
}
"JSONSerialization" is complex to decode this json.
let str = """
{"jsonrpc": "2.0","result": [{"code": 1,"message": "error"},[{"gid": "123"}]]}
"""
let data = str.data(using: .utf8)!
if let json = try! JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any],
let result = json["result"] as? [Any] {
let error = result.map { $0 as? [Any] }.filter { $0 != nil }
let objs = result.map { $0 as? [String: Any] }.filter { $0 != nil }
print(error)
print(objs)
}
Is there a way to decode the JSON payload with JSONDecoder to [Data] or anything else.
struct Result: Codable {
let result: [???] //can't use [Data] here
}
Is there a way to decode the JSON payload with JSONDecoder to [Data] or anything else.
The decode method on JSONDecoder requires some type that conforms to JSONDecodable. True, Any does not conform to Decodable and neither does Data or [Data]. You probably want to define a custom Swift type to represent your JSON and make that conform to Decodable.
How to decode an array with different type inside?
The reason we want to see the complete JSON is that it is useful to know whether the dictionaries and arrays inside result are consistent. If the entries are all like your example, then perhaps you could do something like this:
struct JSONRPC: Decodable {
enum Result: Decodable {
struct ArrayItem: Decodable {
let code: Int
let message: String
}
case array([ArrayItem])
case dictionary(Dictionary<String, String>)
init(from decoder: Decoder) throws {
// Implement decoder for enum with associated values.
// This will not "just work" without your additional
// instructions specifying how to do it. But that's an
// answer for a separate question, I think.
}
}
let version: String
let results: [Result]
private enum CodingKeys: String, CodingKey {
case version = "jsonrpc"
case results = "result"
}
}
With that in place, you can use it like this:
let decoder = JSONDecoder()
let payload = try decoder.decode(JSONRPC.self, from: data)
If the decoding succeeds, then payload will be an instance of RPCJSON.