I am trying to decode the array IGNotification into data that was successfully encoded into a dictionary. Below is my compactMap that should call my Decodable extension, however it looks like my extension is not being called or that the dictionary is not being serialized. Can someone help me as to why this is?
getNotifications function:
public func getNotifications(
completion: #escaping ([IGNotification]) -> Void
) {
guard let username = UserDefaults.standard.string(forKey: "username") else {
completion([])
return
}
let ref = firestoreDatabase.collection("users").document(username).collection("notifications")
ref.getDocuments { snapshot, error in
guard let notifications = snapshot?.documents.compactMap({
IGNotification(with: $0.data())
}),
error == nil else {
completion([])
return
}
completion(notifications)
print(notifications)
}
}
Decodable extension:
extension Decodable {
/// Create model with dictionary
/// - Parameter dictionary: Firestore data
init?(with dictionary: [String: Any]) {
guard let data = try? JSONSerialization.data(
withJSONObject: dictionary,
options: .prettyPrinted)
else {
return nil
}
guard let result = try? JSONDecoder().decode(
Self.self,
from: data
) else {
return nil
}
self = result
}
}
Related
I am parsing data to my Users object from a JSON url and attempting to return the object sorted alphabetically by names. I am having trouble accessing the names property inside of my Users object. I have nested my struct inside of a struct because of the way my JSON is structured. I would like to return the array sorted alphabetically by names in my sortedList array.
struct Response: Codable
{
struct Users: Codable {
var fullName :String
var biography:String
enum CodingKeys: String, CodingKey {
case fullName = "full_name"
case biography
}
}
var users:[Users]
}
// let sortedList = Response{ $0.fullName < $1.fullName }
//Cannot invoke initializer for type 'Response' with an argument list of type '((_, _) -> _)'
func parse(){
guard let url = URL(string: "samplePage.json") else {return}
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard let dataResponse = data,
error == nil else {
print(error?.localizedDescription ?? "Error")
return }
do{
let response = try! JSONDecoder().decode(Response.self, from: dataResponse)
for user in response.users{
print(user.fullName)
print(user.biography)
let sortedArr = user.fullName.sorted{ $0.fullName < $1.fullName }
//Value of type 'Character' has no member 'fullName'
}
} catch let parsingError {
print("Error", parsingError)
}
}
task.resume()
}
For sorting purpose code use like this :
let sortedArr = response.users.sorted{ $0.fullName < $1.fullName }
no need for for loop.
updated code:
func parse(){
guard let url = URL(string: "samplePage.json") else {return}
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard let dataResponse = data,
error == nil else {
print(error?.localizedDescription ?? "Error")
return }
do{
let response = try! JSONDecoder().decode(Response.self, from: dataResponse)
for user in response.users{
print(user.fullName)
print(user.biography)
}
// use code like this
let sortedArr = response.users.sorted{ $0.fullName < $1.fullName }
} catch let parsingError {
print("Error", parsingError)
}
}
task.resume()
}
hello i am working with swift 6.2 ( the performance of my pc doesn't support ++)
i have copied from open classroom this program in my file but there are many errors
i just want to know if it is just problem of swift compatibility or there are really errors in the code
//****************
import UIKit
class QuestionManager {
private let url = URL(string: "https://opentdb.com/api.php?amount=10&type=boolean")!
// exemple of message error: use of unresolved identifier 'URL'
static let shared = QuestionManager()
private init() {}
// FIX IT : replace static with class ...
// AND LOT OF MESSAGE ERROR LIKE THIS...
func get(completionHandler: #escaping ([Question]) -> ()) {
let task = URLSession.shared.dataTask(with: self.url) { (data, response, error) in
guard error == nil else {
completionHandler([Question]())
return
}
DispatchQueue.main.async {
completionHandler(self.parse(data: data))
}
}
task.resume()
}
private func parse(data: Data?) -> [Question] {
guard let data = data,
let serializedJson = try? JSONSerialization.jsonObject(with: data, options: []),
let parsedJson = serializedJson as? [String: Any],
let results = parsedJson["results"] as? [[String: Any]] else {
return [Question]()
}
return getQuestionsFrom(parsedDatas: results)
}
private func getQuestionsFrom(parsedDatas: [[String: Any]]) -> [Question]{
var retrievedQuestions = [Question]()
for parsedData in parsedDatas {
retrievedQuestions.append(getQuestionFrom(parsedData: parsedData))
}
return retrievedQuestions
}
private func getQuestionFrom(parsedData: [String: Any]) -> Question {
if let title = parsedData["question"] as? String,
let answer = parsedData["correct_answer"] as? String {
return Question(title: String(htmlEncodedString: title)!, isCorrect: (answer == "True"))
}
return Question()
}
}
extension String {
init?(htmlEncodedString: String) {
guard let data = htmlEncodedString.data(using: .utf8) else {
return nil
}
let options: [NSAttributedString.DocumentReadingOptionKey: Any] = [
NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html,
NSAttributedString.DocumentReadingOptionKey.characterEncoding: String.Encoding.utf8.rawValue
]
guard let attributedString = try? NSAttributedString(data: data, options: options, documentAttributes: nil) else {
return nil
}
self.init(attributedString.string)
}
}
I'm trying to create a generic decode function to decode my two different models. I get the error "Argument type 'PrivateSchoolType.Type' does not conform to expected type 'Decodable'".
Model
struct PrivateSchoolModel: Decodable {
var name: String
var id: String
var city: String
var state: String
}
Calling Function
function getInfo() {
// does not work => ERROR
guard let schools = decode(jsonData: jsonData, using: PrivateSchoolModel) else { return }
// does work
guard let schools = specificDecode()
}
Specific Decode Function (DOES WORK)
private func specificDecode() -> [PrivateSchoolModel]? {
guard let jsonData = getJSONData(from: .privateSchool) else { return }
do {
let decoder = JSONDecoder()
let schools = try decoder.decode([PrivateSchoolModel].self, from:
jsonData)
return schools
} catch let error {
print("Error: \(error.localizedDescription)")
}
return nil
}
Generic Decode Function (DOES NOT WORK)
private func decode<M: Decodable>(jsonData: Data, using model: M) -> [M]? {
do {
//here dataResponse received from a network request
let decoder = JSONDecoder()
let schools = try decoder.decode([M].self, from:
jsonData) //Decode JSON Response Data
return schools
} catch let parsingError {
print("Error", parsingError)
}
return nil
}
Change the method signature as below,
private func decode<M: Decodable>(jsonData: Data, using modelType: M.Type) -> M? {
do {
//here dataResponse received from a network request
let decoder = JSONDecoder()
let schools = try decoder.decode(modelType, from: jsonData) //Decode JSON Response Data
return schools
} catch let parsingError {
print("Error", parsingError)
}
return nil
}
Usage
guard let schools = decode(jsonData: jsonData, using: [PublicSchoolModel].self) else { return }
I successfully fetched and decoded data from an API and now have access to all the data I need to be used in the algorithm I want to write in my App.
The issue is that I don't know how to access this data after I decoded it, I can print it immediately after it's decoded but I have no idea how to use it in another function or place in my app.
Here is my Playground:
import PlaygroundSupport
PlaygroundPage.current.needsIndefiniteExecution = true
enum MyError : Error {
case FoundNil(String)
}
struct Level: Codable {
let time: Double
let close: Double
let high: Double
let low: Double
let open: Double
}
struct Response: Codable {
let data: [Level]
private enum CodingKeys : String, CodingKey {
case data = "Data"
}
}
func fetchData(completion: #escaping (Response?, Error?) -> Void) {
let url = URL(string: "https://min-api.cryptocompare.com/data/histominute?fsym=BTC&tsym=USD&limit=60&aggregate=3&e=CCCAGG")!
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard let data = data else { return }
do {
if let marketData = try? JSONDecoder().decode(Response.self, from: data) {
print(marketData.data[0].open)
print(marketData.data[1].open)
print("Average=", (marketData.data[0].open + marketData.data[1].open) / 2)
//completion(marketData, nil)
throw MyError.FoundNil("data")
}
} catch {
print(error)
}
}
task.resume()
}
fetchData() { items, error in
guard let items = items,
error == nil else {
print(error ?? "Unknown error")
return
}
print(items)
}
How can I use .data[0], .data[1], ..., somewhere else?
You data will be available in your fecthData() call. Probably what you want is your items variable, where you're printing it. But make sure to call the completion in your fetchData implementation.
WARNING: Untested code.
import PlaygroundSupport
PlaygroundPage.current.needsIndefiniteExecution = true
enum MyError: Error {
case FoundNil(String)
case DecodingData(Data)
}
struct Level: Codable {
let time: Double
let close: Double
let high: Double
let low: Double
let open: Double
}
struct Response: Codable {
let data: [Level]
private enum CodingKeys : String, CodingKey {
case data = "Data"
}
}
func fetchData(completion: #escaping (Response?, Error?) -> Void) {
let url = URL(string: "https://min-api.cryptocompare.com/data/histominute?fsym=BTC&tsym=USD&limit=60&aggregate=3&e=CCCAGG")!
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard let data = data else {
completion(nil, MyError.FoundNil("data"))
}
do {
if let marketData = try? JSONDecoder().decode(Response.self, from: data) {
completion(marketData, nil)
} else {
completion(nil, MyError.DecodingData(data)) // work on this duplicated call
}
} catch {
completion(nil, MyError.DecodingData(data)) // work on this duplicated call
}
}
task.resume()
}
fetchData() { items, error in
if let error == error {
switch(error) {
case .foundNil(let whatsNil):
print("Something is nil: \(whatsNil)")
case .decodingData(let data):
print("Error decoding: \(data)")
}
} else {
if let items = items {
print(items.data[0].open)
print(items.data[1].open)
print("Average=", (items.data[0].open + items.data[1].open) / 2)
print(items)
} else {
print("No items to show!")
}
}
}
I don't understand what is your real issue, because you have written everything you need here, but as far I understand , to pass data
just uncomment this line completion(marketData, nil)
and in
fetchData() { items, error in
guard let items = items,
error == nil else {
print(error ?? "Unknown error")
return
}
print(items)
}
items is an object of your struct Response. You can pass this anywhere in your other class , by just creating an another variable like:
var items : Response!
for example :
class SomeOtherClass : NSObject{
var items : Response!
func printSomeData()
{
print(items.data[0].open)
print(items.data[1].open)
print("Average=", (items.data[0].open + items.data[1].open) / 2)
}
}
and in fetchData method write this:
fetchData() { items, error in
guard let items = items,
error == nil else {
print(error ?? "Unknown error")
return
}
let otherObject = SomeOtherClass()
otherObject.items = items
otherObject.printSomeData()
}
I have several codable structs and I'd like to create a universal protocol to code them to CKRecord for CloudKit and decode back.
I have an extension for Encodable to create a dictionary:
extension Encodable {
var dictionary: [String: Any] {
return (try? JSONSerialization.jsonObject(with: JSONEncoder().encode(self), options: .allowFragments)) as? [String: Any] ?? [:]
}
}
Then in a protocol extension, I create the record as a property and I try to create a CKAsset if the type is Data.
var ckEncoded: CKRecord? {
// Convert self.id to CKRecord.name (CKRecordID)
guard let idString = self.id?.uuidString else { return nil }
let record = CKRecord(recordType: Self.entityType.rawValue,
recordID: CKRecordID(recordName: idString))
self.dictionary.forEach {
if let data = $0.value as? Data {
if let asset: CKAsset = try? ckAsset(from: data, id: idString) { record[$0.key] = asset }
} else {
record[$0.key] = $0.value as? CKRecordValue
}
}
return record
}
To decode:
func decode(_ ckRecord: CKRecord) throws {
let keyIntersection = Set(self.dtoEncoded.dictionary.keys).intersection(ckRecord.allKeys())
var dictionary: [String: Any?] = [:]
keyIntersection.forEach {
if let asset = ckRecord[$0] as? CKAsset {
dictionary[$0] = try? self.data(from: asset)
} else {
dictionary[$0] = ckRecord[$0]
}
}
guard let data = try? JSONSerialization.data(withJSONObject: dictionary) else { throw Errors.LocalData.isCorrupted }
guard let dto = try? JSONDecoder().decode(self.DTO, from: data) else { throw Errors.LocalData.isCorrupted }
do { try decode(dto) }
catch { throw error }
}
Everything works forth and back except the Data type. It can't be recognized from the dictionary. So, I can't convert it to CKAsset. Thank you in advance.
I have also found there is no clean support for this by Apple so far.
My solution has been to manually encode/decode: On my Codable subclass I added two methods:
/// Returns CKRecord
func ckRecord() -> CKRecord {
let record = CKRecord(recordType: "MyClassType")
record["title"] = title as CKRecordValue
record["color"] = color as CKRecordValue
return record
}
init(withRecord record: CKRecord) {
title = record["title"] as? String ?? ""
color = record["color"] as? String ?? kDefaultColor
}
Another solution for more complex cases is use some 3rd party lib, one I came across was: https://github.com/insidegui/CloudKitCodable
So I had this problem as well, and wasn't happy with any of the solutions. Then I found this, its somewhat helpful, doesn't handle partial decodes very well though https://github.com/ggirotto/NestedCloudkitCodable