swift: diction list to json

Question

How i can convert diction list to json ?

struct User: Codable {
    var id = ""
    var deviceName = ""
}

    var userList:[Any] = []
    for user in users {
        var b : [String: Any] = [:]
        b["name"] = user.deviceName
        b["id"] = user.id
        //        b["uuid"] = user.uuid.uuidString
        userList.append(b)
        
    }
    print(JSONSerialization.isValidJSONObject(userList))
    
    do {
        let jsonData = try JSONSerialization.data(withJSONObject: userList, options: .prettyPrinted)
        return .ok(.json(jsonData))
    } catch {
        return .ok(.htmlBody("Error"))
    }

terminating with uncaught exception of type NSException *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Invalid type in JSON write (__NSConcreteUUID)' terminating with uncaught exception of type NSException

Or better, use `Codable` and encode users directly using `JSONEncoder`. — Sulthan, Jul 16 '21 at 19:25

Mojtaba Hosseini · Accepted Answer · 2021-07-16T20:51:41.997

1

You can use the Codable to easily encode and decode your object and JSONs:

do {
    let jsonEncoder = JSONEncoder()
    let jsonData = try jsonEncoder.encode(users)
    ,,,
} catch {
    print(error)
    return .ok(.htmlBody("\(error.localizedDescription)"))
}

Some side notes:

Always try print out the real error instead of throwing a simple string.
Catch means there where an error. So you may consider returning a badRequest or something instead of ok.

It seems like you need to pass a JSON. So you can convert the jsonData to a jsonObject like:

    let jsonObject = try JSONSerialization.jsonObject(with: jsonData, options: [])
    print(JSONSerialization.isValidJSONObject(jsonObject)) // <- to verify
    return .ok(.json(jsonObject))

edited Jul 16 '21 at 20:51

answered Jul 16 '21 at 20:15

Mojtaba Hosseini

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thanks for your answer, but, `print(JSONSerialization.isValidJSONObject(jsonData))` is FALSE – Wang Liang Jul 16 '21 at 20:17
in the `.json` fucntion, there is `JSONSerialization.isValidJSONObject` – Wang Liang Jul 16 '21 at 20:18
`let jsonData = try jsonEncoder.encode(users)` return empty data – Wang Liang Jul 16 '21 at 20:23
Are you sure `users` is not empty before passing it to the decoder? I've tested the code and it works. please get rid of all side effects and test again. – Mojtaba Hosseini Jul 16 '21 at 20:27
if possible, could you check https://stackoverflow.com/questions/68414125/with-swifter-json-response ? – Wang Liang Jul 16 '21 at 20:42
i used `swifter` library, and, i found in the library: there is ` case .json(let object): guard JSONSerialization.isValidJSONObject(object) else { throw SerializationError.invalidObject } let data = try JSONSerialization.data(withJSONObject: object) return (data.count, { try $0.write(data) })` So, i need pass `guard JSONSerialization.isValidJSONObject(object)` – Wang Liang Jul 16 '21 at 20:43
You need to pass a JSON, not jsonData – Mojtaba Hosseini Jul 16 '21 at 20:49
So, How I can get `JSON` ? – Wang Liang Jul 16 '21 at 20:51
Please don't add extra questions to an existing question, just ask another question. – Abizern Jul 16 '21 at 23:28
@Abizern, Yes, I will sovle – Wang Liang Jul 17 '21 at 00:46

swift: diction list to json

1 Answers1