How to get single object JSON API in SwiftUI

Question

Created Mar ’21

Replies 8

Boosts 0

Views 2.7k

Participants 3

I am trying to get the data from this API - (api.solunar.org/solunar/42.66,-84.07,20180207,-4). I found this tutorial (youtube.com/watch?v=gfOhBmU2cPM), but it is for a list of objects JSON API, whereas mine is just 1 single object... Does anyone know how to edit the code from the video to work with my API?

Answered by OOPer in 668996022

I need to edit it to be for a single object.

Sorry, I have been missing your words my old code the gets a multi-object array.

But you just need to pass the struct type to decode(_:from:) instead of Array type:
For example:

Code Block struct SingleObject: Codable {
    var sunRise: String
    //...
}
enum ApiError: Error {
    case dataIsNil
}
class ApiCall {
    func getSingleObject(completion:@escaping (Result<SingleObject, Error>) -> ()) {
        guard let url = URL(string: "...") else { return }
        URLSession.shared.dataTask(with: url) { (data, _, error) in
            if let error = error {
                print(error)
                completion(.failure(error))
                return
            }
            guard let data = data else {
                print("data is nil")
                completion(.failure(ApiError.dataIsNil))
                return
            }
            do {
                let singleObject = try JSONDecoder().decode(SingleObject.self, from: data) //<-
                print(singleObject)
                
                DispatchQueue.main.async {
                    completion(.success(singleObject))
                }
            } catch {
                print(error)
                completion(.failure(error))
            }
        }
        .resume()
    }
}

Boost

Answer 1

Claude31 OP

Mar ’21

Could you please select in referenced links and post:

the part of code you want to adapt
the adaptations you did (what are your own objects to decode)
explain what you tried,
what doesn't work ?

Not sure many here have time or intent to go and search for relevant code.

0

Answer 2

charliekingsland OP

Mar ’21

I tried using referenced links, but the forums wouldn’t allow them, so I just put them in plain text...

I haven’t attempted editing my old code the gets a multi-object array, as I don’t know where to start. My code is attached

My code

0

Answer 3

OOPer OP

Mar ’21

Can you show the example response as JSON text?

And I need to ask one more question. Why the completion of your getUsers(completion:) takes [Launch]?
You say it is a single object, not an Array.

0

Answer 4

charliekingsland OP

Mar ’21

The code I posted is my code for getting a multi-object JSON array, and I need to edit it to be for a single object.

Example single object response

0

Answer 5

OOPer OP

Mar ’21

Accepted Answer

I need to edit it to be for a single object.

Sorry, I have been missing your words my old code the gets a multi-object array.

But you just need to pass the struct type to decode(_:from:) instead of Array type:
For example:

Code Block struct SingleObject: Codable {
    var sunRise: String
    //...
}
enum ApiError: Error {
    case dataIsNil
}
class ApiCall {
    func getSingleObject(completion:@escaping (Result<SingleObject, Error>) -> ()) {
        guard let url = URL(string: "...") else { return }
        URLSession.shared.dataTask(with: url) { (data, _, error) in
            if let error = error {
                print(error)
                completion(.failure(error))
                return
            }
            guard let data = data else {
                print("data is nil")
                completion(.failure(ApiError.dataIsNil))
                return
            }
            do {
                let singleObject = try JSONDecoder().decode(SingleObject.self, from: data) //<-
                print(singleObject)
                
                DispatchQueue.main.async {
                    completion(.success(singleObject))
                }
            } catch {
                print(error)
                completion(.failure(error))
            }
        }
        .resume()
    }
}

1

Answer 6

charliekingsland OP

Apr ’21

How do I then get the data from that into a variable? My multi-object one did it along the lines of:

Code Block swift@State var moons: [SingleObject] = []
.onAppear {
    ApiCall().getSingleObject{ (moons) in self.moons = moons}
}

0

Answer 7

OOPer OP

Apr ’21

UPDATE: Assuming you are using my code with Result as is...

How do I then get the data from that into a variable?

Code Block @State var singleObject: SingleObject? 
            .onAppear {
                ApiCall().getSingleObject{ result in
                    switch result {
                    case .success(let singleObject):
                        self.singleObject = singleObject
                    case .failure(let error):
                        print(error)
                    }
                }
            }

You say a single object, you usually do not use an Array for a single object.

0

Answer 8

charliekingsland OP

Apr ’21

Thanks, it works!

0