json array shows in debugger but can't parse

Question

Cotherstone OP

Created 4d

Replies 1

Boosts 0

Participants 2

Hello,

I asked this question on 9th March but was asked to provide a project file and can't edit the original post. Please find the original question below and please find the new test project file at https://we.tl/t-fqAu8FrgUw.

I have a json array showing in Xcode debugger (from the line "print(dataString)"):

Optional("[{\"id\":\"8e8tcssu4u2hn7a71tkveahjhn8xghqcfkwf1bzvtrw5nu0b89w\",\"name\":\"Test name 0\",\"country\":\"Test country 0\",\"type\":\"Test type 0\",\"situation\":\"Test situation 0\",\"timestamp\":\"1546848000\"},{\"id\":\"z69718a1a5z2y5czkwrhr1u37h7h768v05qr3pf1h4r4yrt5a68\",\"name\":\"Test name 1\",\"country\":\"Test country 1\",\"type\":\"Test type 1\",\"situation\":\"Test situation 1\",\"timestamp\":\"1741351615\"},{\"id\":\"fh974sv586nhyysbhg5nak444968h7hgcgh6yw0usbvcz9b0h69\",\"name\":\"Test name 2\",\"country\":\"Test country 2\",\"type\":\"Test type 2\",\"situation\":\"Test situation 2\",\"timestamp\":\"1741351603\"},{\"id\":\"347272052385993\",\"name\":\"Test name 3\",\"country\":\"Test country 3\",\"type\":\"Test type 3\",\"situation\":\"Test situation 3\",\"timestamp\":\"1741351557\"}]")

But my JSON decoder is throwing the catch error "Error in JSON parsing"

This is the code:


        let urlString = "https://www.notafunnyname.com/jsonmockup.php"
        let url = URL(string: urlString)
        
        guard url != nil else {
            return
        }
        
        let session = URLSession.shared
        
        let dataTask = session.dataTask(with: url!) { (data, response, error) in
           
            var dataString = String(data: data!, encoding: String.Encoding.utf8)
            print(dataString)
            
            if error == nil && data != nil {
                // Parse JSON
                let decoder = JSONDecoder()
                
                do {
                    
                let newsFeed = try decoder.decode(NewsFeed.self, from: data!)
                    
                    print(newsFeed)
                    print(error)
                    
                }
                catch{
                    print("Error in JSON parsing")
                }
                
            }
        }
        
        // Make the API Call
        dataTask.resume()
    }

And this is my Codable file NewsFeed.swift:

struct NewsFeed: Codable {
        
        var id: String
        var name: String
        var country: String
        var type: String
        var overallrecsit: String
        var dlastupd: String
        var doverallrecsit: String
        
    }

Please do you know why the parsing may be failing? Is it significant that in the debugging window the JSON is displaying backslashes before the quotation marks?

Thank you for any pointers :-)

Answered by darkpaw in 829372022

This is one of the items in your JSON data:

"id":"8e8tcssu4u2hn7a71tkveahjhn8xghqcfkwf1bzvtrw5nu0b89w",
"name":"Test name 0",
"country":"Test country 0",
"type":"Test type 0",
"situation":"Test situation 0",
"timestamp":"1546848000"

If you're decoding into your NewsFeed struct then the JSON needs to match that struct.

Here's your struct:

var id: String  // Yep, this is fine
var name: String  // Fine
var country: String  // Fine
var type: String  // Fine
var overallrecsit: String  // What's this? I'm expecting 'situation'...
var dlastupd: String  // What's this? `timestamp`, maybe?
var doverallrecsit: String  // No idea

How can you expect to decode some JSON into a struct that doesn't match it?

Boost

Answer 1

darkpaw OP

4d

Accepted Answer

This is one of the items in your JSON data:

"id":"8e8tcssu4u2hn7a71tkveahjhn8xghqcfkwf1bzvtrw5nu0b89w",
"name":"Test name 0",
"country":"Test country 0",
"type":"Test type 0",
"situation":"Test situation 0",
"timestamp":"1546848000"

If you're decoding into your NewsFeed struct then the JSON needs to match that struct.

Here's your struct:

var id: String  // Yep, this is fine
var name: String  // Fine
var country: String  // Fine
var type: String  // Fine
var overallrecsit: String  // What's this? I'm expecting 'situation'...
var dlastupd: String  // What's this? `timestamp`, maybe?
var doverallrecsit: String  // No idea

How can you expect to decode some JSON into a struct that doesn't match it?

0