How to create JSON from a dictionary in Swift 4? - json

Question

Edit: I have read the other answers on SO for the same issue , however Im unable to get the desired output. I have tried many variations as suggested in other questions but its not working.
I have a JSON snipped which needs to be added as the body when I open a websocket.
sender: "system1#example.com",
recipients:"system2#example.com",
data: {
text: "Test Message"
},
So using Swift I did the following,
var messageDictionary : [String: Any] = [
"sender": "system1#example.com",
"recipients":"system2#example.com",
"data": [
"text": "Test Message"
],
]
do {
let jsonData = try JSONSerialization.data(withJSONObject: messageDictionary, options: .prettyPrinted)
let jsonString = String(data: jsonData, encoding: String.Encoding.ascii)
socket.write(string: jsonString!)
print(jsonString)
} catch {
print(error.localizedDescription)
}
When I print the jsonString, I get
Optional("{\n \"sender\" : \"system1#example.com\",\n \"data\" : {\n
\"text\" : \"Test Message\"\n },\n \"recipients\" :
\"system2#example.com\"\n}")
as the console output. I expected the above snippet to be formatted as JSON.
How to get the output as normal JSON without the /n and additional spaces?
Im using Swift 4 and Xcode 9.1
Edit 2:
let jsonData = try JSONSerialization.data(withJSONObject: messageDictionary, options: [])
let decoded = try JSONSerialization.jsonObject(with: jsonData, options: [])
I tried doing the above and I get the following as the output:
{
data = {
text = Test Message;
};
recipients = "system1#example.com";
sender = "system2#example.com";
}
However the websocket expects this:
{ "sender":"system1#example.com","recipients":
["system2#example.com"],"data":{"text":"Test Message"}}
Even with a slight variation like misplacing of double quotes the websocket server doesnt accept the input. How to exactly format the JSOn this way so that the websocket can accept it?

Answer 1

After trying out various ways, the below way is what worked for me for getting the exact format required by the backend.
var messageDictionary = [
"sender":"system1#example.com",
"recipients":[
"system2#example.com"
],
"data":[
"text" : data
]
] as [String : Any]
let jsonData = try! JSONSerialization.data(withJSONObject: messageDictionary)
let jsonString = NSString(data: jsonData, encoding: String.Encoding.utf8.rawValue)

Answer 2

Additionally, you can just cast to String
let jsonData = try? JSONSerialization.data(withJSONObject: dict, options: .prettyPrinted)
let jsonString = String(data: jsonData!, encoding: .utf8)

Answer 3

Now JSONEncoder can do the work easily.
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
let data = try encoder.encode(yourDictionary)
print(String(data: data, encoding: .utf8)!)