Decode JSON Array with no Attribute Name - json

Question

I have looked through other threads regarding trying to parse JSON data where a JSON array has no name. From what I have found you need to use a unkeyedContainer but I'm not entirely sure from the examples I have seen how this works with the data model.
Below is a snippet of data from open charge api:
[
{
"IsRecentlyVerified": false,
"ID": 136888,
"UUID": "254B0B07-E7FC-4B4B-A37C-899BCB9D7261",
"DataProviderID": 18,
"DataProvidersReference": "0a9fdbb17feb6ccb7ec405cfb85222c4",
"OperatorID": 3,
"UsageTypeID": 1,
"AddressInfo": {
"ID": 137234,
"Title": "Ballee Road Park & Share",
"AddressLine1": "Ballee Road",
"Town": "Ballymena",
"Postcode": "BT42 2HD",
"CountryID": 1,
"Latitude": 54.844648,
"Longitude": -6.273606,
"AccessComments": "Ballee Road Park and Share, Ballymena",
"RelatedURL": "http://pod-point.com",
"Distance": 3.81818421833416,
"DistanceUnit": 2
},
"Connections": [
{
"ID": 191571,
"ConnectionTypeID": 25,
"Reference": "1",
"StatusTypeID": 50,
"LevelID": 2,
"Amps": 32,
"Voltage": 400,
"PowerKW": 22,
"CurrentTypeID": 20
},
It looks to me that the first [ and { have no attribute names which I belive is creating the error in xcode: "Error!: typeMismatch(Swift.Dictionary<Swift.String, Any>, Swift.DecodingError.Context(codingPath: [], debugDescription: "Expected to decode Dictionary<String, Any> but found an array instead.", underlyingError: nil))"
Here is my data model:
import Foundation
struct PublicCharger: Decodable {
let AddressInfo: [AddressInfo]
}
Here is my code:
//Find public chargers from local coordinates
func findPublicChargers(lat: Double, long: Double) {
//Use apiurl to pull all charge points that are currently in that area by adding lat and long into the api call &latitude=***&longitude=*****
let apiurl = "https://api.openchargemap.io/v3/poi/?output=json&countrycode=UK&maxresults=100&compact=true&verbose=false"
let urlString = "\(apiurl)&latitude=\(lat)&longitude=\(long)"
//print(urlString)
performRequest(urlString: urlString)
}
//Perform API Request - (London App Brewry code)
//Create the custom url
func performRequest(urlString: String) {
if let url = URL(string: urlString) {
//print("Called")
//Create a URL Session
let session = URLSession(configuration: .default)
//Give the session a task
let task = session.dataTask(with: url) { (data, response, error) in
if error != nil {
print(error!)
return
}
if let safeData = data {
//let dataString = String(data: safeData, encoding: .utf8)
//print(dataString)
self.parseJSON(data: safeData)
print("Data: \(safeData)")
}
}
//Start the task
task.resume()
}
}
func parseJSON(data: Data){
let decoder = JSONDecoder()
do {
let decodedData = try decoder.decode(PublicCharger.self, from: data)
print("Data: \(decodedData.AddressInfo[0].Title)")
} catch {
print("Error!: \(error)")
}
}
struct AddressInfo: Decodable {
let Title: String
}
I have seen that in the data model you would need to include an unkeyed container element. I'm just not sure how this should be carried out in the data model. Any light on this would be much appreciated.

Answer 1

Try to change your PublicCharger data model to
struct PublicCharger: Decodable {
let AddressInfo: [AddressInfo]
}
And your parseJSON function to
func parseJSON(data: Data){
let decoder = JSONDecoder()
do {
let decodedData = try decoder.decode([PublicCharger].self, from: data)
if !decodedData.isEmpty {
print("Data: \(decodedData[0].AddressInfo[0].Title)")
} else {
print("Empty result!")
}
} catch {
print("Error!: \(error)")
}
}