Swift: How to parse and decode JSON containing an array of dictionaries - json

Question

I'm trying to parse the JSON at a certain API endpoint using the Codable protocol in Swift. How do you properly decode this?
So far, I've created a Model struct to represent the Post objects located at the endpoint. I'm also using JSONDecoder() to decode the array of Post objects. I've tried restructuring my Model to have nested structs but that doesn't work.
Here's a sample of the JSON:
[
{
"ID": 1,
"title": "Title 1",
"content": "Content 1"
...
},
{
"ID": 2,
"title": "Title 2",
"content": "Content 2"
...
}
]
Here's the Model:
struct Post: Codable {
let id: Int
let title, content: String
enum CodingKeys: String, CodingKey {
case id = "ID"
case title, content
}
}
Here's a sample of the fetching code:
let task = URLSession.shared.dataTask(with: url) {
data, _, error in
if let error = error {
print("Error: Failed to fetch data from url. [\(error.localizedDescription)]")
completion(.failure(error))
return
}
guard let data = data else {
print("Data not available.")
return
}
do {
let decoder = JSONDecoder()
let posts = try decoder.decode([Post].self, from: data)
print("POSTS: : ", posts)
// ^ THIS IS NOT WORKING. I've tried Post.self too.
} catch let jsonError {
//error
}
}
task.resume()
Here's the error I'm getting:
ERROR: keyNotFound(CodingKeys(stringValue: "ID", intValue: nil), Swift.DecodingError.Context(codingPath: [_JSONKey(stringValue: "Index 0", intValue: 0)], debugDescription: "No value associated with key CodingKeys(stringValue: \"ID\", intValue: nil) (\"ID\").", underlyingError: nil))

Answer 1

Your code is just fine. You just need to check your json data. This error shows in the case:
When certain key in Coding keys doesn't match with the key of json data. In your case it is clearly = "ID"
To solve this check response in postMan and make the keys exactly same in Codingkeys