How to parse array of objects of json with SwiftUI - json

Question

completely new to Swift here, so I have no idea how to even use print debugging, so thought I would ask here.
I am trying to parse a series of objects, each one of them in this format:
{
"id": 0,
"title": "Example Title",
"targets": [
{
"name": "Example Name"
},
{
"name": "Example Name"
},
{
"name": "Example Name"
},
{
"name": "Example Name"
}
],
"benefits": [
{
"name": "Example Benefit"
},
{
"name": "Example Benefit"
},
{
"name": "Example Benefit"
}
],
"steps": [
{
"name": "Example Step"
},
{
"name": "Example Step"
}
],
"videoURL": "https://someurl.com"
},
So I have a struct defined as such
struct Obj: Codable, Hashable {
var id:Int
var title:String
var targets:[String]
var benefits:[String]
var steps:[String]
var videoURL:String
}
And using
let objs:[Obj] = decode([Obj].self, from: "./Data/Objs.json")
Where decode is this function
func decode<T: Decodable>(_ type:T.Type, from filename:String) -> T {
guard let json = Bundle.main.url(forResource: filename, withExtension: nil) else {
fatalError("Failed to locate \(filename) in app bundle.")
}
guard let jsonData = try? Data(contentsOf: json) else {
fatalError("Failed to load \(filename) from app bundle.")
}
let decoder = JSONDecoder()
guard let result = try? decoder.decode(T.self, from: jsonData) else {
fatalError("Failed to decode \(filename) from app bundle.")
}
return result
}
However when accessing the data in Objs, I get an error in the SwiftUI preview objs.app may have crashed. Check ... for any crash logs in your application which leads me to believe I am using JSONDecoder() incorrectly. Any help is appreciated!

Answer 1

So the problem here is how you are decoding inner content of the targets, steps and benifits.
Targets/Steps/Benifit contains array of object but in the Codable structure of yours, you have given it as a array of strings [String]. You need to correct that and Check.
Create one new structure:
struct Name : Codable {
var name : String
}
Your final object will look like:
struct Obj: Codable, Hashable {
var id:Int
var title:String
var targets:[Name]
var benefits:[Name]
var steps:[Name]
var videoURL:String
}
The key thing you should remember is that at the time of parsing nested object you will have to create another structure with codable conformance.