I am trying to convert a dictionary to json string without space and new line. I tried to use JSONSerialization.jsonObject but I still can see spaces and new lines. Is there any way to have a string result looks something like this
"data": "{\"requests\":[{\"image\":{\"source\":{\"imageUri\":\"https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png\"}},\"features\":[{\"type\":\"LOGO_DETECTION\",\"maxResults\":1}]}]}"
My conversion
var features = [[String: String]]()
for detection in detections {
features.append(["type": imageDetection[detection]!])
}
let content = ["content": base64Image]
let request = ["image": content, "features": features] as [String : Any]
let requests = ["requests": [request]]
let jsonData = try! JSONSerialization.data(withJSONObject: requests, options: .prettyPrinted)
let decoded = try! JSONSerialization.jsonObject(with: jsonData, options: [])
print(decoded)
Result
{
requests = (
{
features = (
{
type = "LABEL_DETECTION";
},
{
type = "WEB_DETECTION";
},
{
type = "TEXT_DETECTION";
}
);
image = {
content = "iVBO
...........
You are decoding the serialized JSON into an object. When an object is printed into the console, you will see the indentation, and the use of equals symbols and parentheses.
Remove the .prettyPrinted option and use the data to initialize a string with .utf8 encoding.
let jsonData = try! JSONSerialization.data(withJSONObject: requests, options: [])
let decoded = String(data: jsonData!, encoding: .utf8)!
Related
I'm trying to encode an integer that starts with a 0 into JSON using swift 4.
I'm using a pretty standard JSONSerialization library, but for some reason, after converting the string to data using utf8, I cannot serialize it.
let code = "012345" // example code
let body = "{\"code\": " + code + "}"
let stringData = body.data(using: .utf8)!
let jsonArray = try? JSONSerialization.jsonObject(with: stringData, options : .allowFragments) [returns nil]
let data: Data? = try? JSONSerialization.data(withJSONObject: jsonArray as Any, options: .prettyPrinted)
Currently, the code breaks on the second to last line (starting with let jsonArray) and returns nil. Note that if I were to change code to "112345", there would be no error. Any help is appreciated, thanks!
Instead of manually creating string, use Dictionary and JSONSerialization to create data as below,
let code = "012345"
let body: [String: Any] = ["code": code]
do {
let stringData = try JSONSerialization.data(withJSONObject: body, options: .sortedKeys)
print(String.init(data: stringData, encoding: .utf8)!)
} catch {
print(error)
}
Output
{"code":"012345"}
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?
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)
Additionally, you can just cast to String
let jsonData = try? JSONSerialization.data(withJSONObject: dict, options: .prettyPrinted)
let jsonString = String(data: jsonData!, encoding: .utf8)
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)!)
How do you convert an array to a JSON string in swift?
Basically I have a textfield with a button embedded in it.
When button is pressed, the textfield text is added unto the testArray.
Furthermore, I want to convert this array to a JSON string.
This is what I have tried:
func addButtonPressed() {
if goalsTextField.text == "" {
// Do nothing
} else {
testArray.append(goalsTextField.text)
goalsTableView.reloadData()
saveDatatoDictionary()
}
}
func saveDatatoDictionary() {
data = NSKeyedArchiver.archivedDataWithRootObject(testArray)
newData = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions(), error: nil) as? NSData
string = NSString(data: newData!, encoding: NSUTF8StringEncoding)
println(string)
}
I would also like to return the JSON string using my savetoDictionart() method.
As it stands you're converting it to data, then attempting to convert the data to to an object as JSON (which fails, it's not JSON) and converting that to a string, basically you have a bunch of meaningless transformations.
As long as the array contains only JSON encodable values (string, number, dictionary, array, nil) you can just use NSJSONSerialization to do it.
Instead just do the array->data->string parts:
Swift 3/4
let array = [ "one", "two" ]
func json(from object:Any) -> String? {
guard let data = try? JSONSerialization.data(withJSONObject: object, options: []) else {
return nil
}
return String(data: data, encoding: String.Encoding.utf8)
}
print("\(json(from:array as Any))")
Original Answer
let array = [ "one", "two" ]
let data = NSJSONSerialization.dataWithJSONObject(array, options: nil, error: nil)
let string = NSString(data: data!, encoding: NSUTF8StringEncoding)
although you should probably not use forced unwrapping, it gives you the right starting point.
Swift 3.0 - 4.0 version
do {
//Convert to Data
let jsonData = try JSONSerialization.data(withJSONObject: dictionaryOrArray, options: JSONSerialization.WritingOptions.prettyPrinted)
//Convert back to string. Usually only do this for debugging
if let JSONString = String(data: jsonData, encoding: String.Encoding.utf8) {
print(JSONString)
}
//In production, you usually want to try and cast as the root data structure. Here we are casting as a dictionary. If the root object is an array cast as [Any].
var json = try JSONSerialization.jsonObject(with: jsonData, options: JSONSerialization.ReadingOptions.mutableContainers) as? [String: Any]
} catch {
print(error.description)
}
The JSONSerialization.WritingOptions.prettyPrinted option gives it to the eventual consumer in an easier to read format if they were to print it out in the debugger.
Reference: Apple Documentation
The JSONSerialization.ReadingOptions.mutableContainers option lets you mutate the returned array's and/or dictionaries.
Reference for all ReadingOptions: Apple Documentation
NOTE: Swift 4 has the ability to encode and decode your objects using a new protocol. Here is Apples Documentation, and a quick tutorial for a starting example.
If you're already using SwiftyJSON:
https://github.com/SwiftyJSON/SwiftyJSON
You can do this:
// this works with dictionaries too
let paramsDictionary = [
"title": "foo",
"description": "bar"
]
let paramsArray = [ "one", "two" ]
let paramsJSON = JSON(paramsArray)
let paramsString = paramsJSON.rawString(encoding: NSUTF8StringEncoding, options: nil)
SWIFT 3 UPDATE
let paramsJSON = JSON(paramsArray)
let paramsString = paramsJSON.rawString(String.Encoding.utf8, options: JSONSerialization.WritingOptions.prettyPrinted)!
JSON strings, which are good for transport, don't come up often because you can JSON encode an HTTP body. But one potential use-case for JSON stringify is Multipart Post, which AlamoFire nows supports.
How to convert array to json String in swift 2.3
var yourString : String = ""
do
{
if let postData : NSData = try NSJSONSerialization.dataWithJSONObject(yourArray, options: NSJSONWritingOptions.PrettyPrinted)
{
yourString = NSString(data: postData, encoding: NSUTF8StringEncoding)! as String
}
}
catch
{
print(error)
}
And now you can use yourSting as JSON string..
Swift 5
This generic extension will convert an array of objects to a JSON string from which it can either be:
saved to the App's Documents Directory (iOS/MacOS)
output directly to a file on the Desktop (MacOS)
.
extension JSONEncoder {
static func encode<T: Encodable>(from data: T) {
do {
let jsonEncoder = JSONEncoder()
jsonEncoder.outputFormatting = .prettyPrinted
let json = try jsonEncoder.encode(data)
let jsonString = String(data: json, encoding: .utf8)
// iOS/Mac: Save to the App's documents directory
saveToDocumentDirectory(jsonString)
// Mac: Output to file on the user's Desktop
saveToDesktop(jsonString)
} catch {
print(error.localizedDescription)
}
}
static private func saveToDocumentDirectory(_ jsonString: String?) {
guard let path = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return }
let fileURL = path.appendingPathComponent("Output.json")
do {
try jsonString?.write(to: fileURL, atomically: true, encoding: .utf8)
} catch {
print(error.localizedDescription)
}
}
static private func saveToDesktop(_ jsonString: String?) {
let homeURL = FileManager.default.homeDirectoryForCurrentUser
let desktopURL = homeURL.appendingPathComponent("Desktop")
let fileURL = desktopURL.appendingPathComponent("Output.json")
do {
try jsonString?.write(to: fileURL, atomically: true, encoding: .utf8)
} catch {
print(error.localizedDescription)
}
}
}
Example:
struct Person: Codable {
var name: String
var pets: [Pet]
}
struct Pet: Codable {
var type: String
}
extension Person {
static func sampleData() -> [Person] {
[
Person(name: "Adam", pets: []),
Person(name: "Jane", pets: [
Pet(type: "Cat")
]),
Person(name: "Robert", pets: [
Pet(type: "Cat"),
Pet(type: "Rabbit")
])
]
}
}
Usage:
JSONEncoder.encode(from: Person.sampleData())
Output:
This will create the following correctly formatted Output.json file:
[
{
"name" : "Adam",
"pets" : [
]
},
{
"name" : "Jane",
"pets" : [
{
"type" : "Cat"
}
]
},
{
"name" : "Robert",
"pets" : [
{
"type" : "Cat"
},
{
"type" : "Rabbit"
}
]
}
]
SWIFT 2.0
var tempJson : NSString = ""
do {
let arrJson = try NSJSONSerialization.dataWithJSONObject(arrInvitationList, options: NSJSONWritingOptions.PrettyPrinted)
let string = NSString(data: arrJson, encoding: NSUTF8StringEncoding)
tempJson = string! as NSString
}catch let error as NSError{
print(error.description)
}
NOTE:- use tempJson variable when you want to use.
extension Array where Element: Encodable {
func asArrayDictionary() throws -> [[String: Any]] {
var data: [[String: Any]] = []
for element in self {
data.append(try element.asDictionary())
}
return data
}
}
extension Encodable {
func asDictionary() throws -> [String: Any] {
let data = try JSONEncoder().encode(self)
guard let dictionary = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String: Any] else {
throw NSError()
}
return dictionary
}
}
If you're using Codable protocols in your models these extensions might be helpful for getting dictionary representation (Swift 4)
Hint: To convert an NSArray containing JSON compatible objects to an NSData object containing a JSON document, use the appropriate method of NSJSONSerialization. JSONObjectWithData is not it.
Hint 2: You rarely want that data as a string; only for debugging purposes.
For Swift 4.2, that code still works fine
var mnemonic: [String] = ["abandon", "amount", "liar", "buyer"]
var myJsonString = ""
do {
let data = try JSONSerialization.data(withJSONObject:mnemonic, options: .prettyPrinted)
myJsonString = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as! String
} catch {
print(error.localizedDescription)
}
return myJsonString
Swift 5
Make sure your object confirm Codable.
Swift's default variable types like Int, String, Double and ..., all are Codable that means we can convert theme to Data and vice versa.
For example, let's convert array of Int to String Base64
let array = [1, 2, 3]
let data = try? JSONEncoder().encode(array)
nsManagedObject.array = data?.base64EncodedString()
Make sure your NSManaged variable type is String in core data schema editor and custom class if your using custom class for core data objects.
let's convert back base64 string to array:
var getArray: [Int] {
guard let array = array else { return [] }
guard let data = Data(base64Encoded: array) else { return [] }
guard let val = try? JSONDecoder().decode([Int].self, from: data) else { return [] }
return val
}
Do not convert your own object to Base64 and store as String in CoreData and vice versa because we have something that named Relation in CoreData (databases).
For Swift 3.0 you have to use this:
var postString = ""
do {
let data = try JSONSerialization.data(withJSONObject: self.arrayNParcel, options: .prettyPrinted)
let string1:String = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as! String
postString = "arrayData=\(string1)&user_id=\(userId)&markupSrcReport=\(markup)"
} catch {
print(error.localizedDescription)
}
request.httpBody = postString.data(using: .utf8)
100% working TESTED
You can try this.
func convertToJSONString(value: AnyObject) -> String? {
if JSONSerialization.isValidJSONObject(value) {
do{
let data = try JSONSerialization.data(withJSONObject: value, options: [])
if let string = NSString(data: data, encoding: String.Encoding.utf8.rawValue) {
return string as String
}
}catch{
}
}
return nil
}
I'm trying to parse Json Data from an API :
{
"title": "Mr. Robot",
"first_aired": "2015-06-24",
"network": "USA Network",
"channels": [
{
"id": 12,
"name": "USA",
"short_name": "usa",
"channel_type": "television"
}
],
The Code I'm use is:
var TVArray : [TVInfo] = []
var task : NSURLSessionTask?
func getJSON (urlString: String) {
let url = NSURL(string: urlString)!
let session = NSURLSession.sharedSession()
task = session.dataTaskWithURL(url) {(data, response, error) in
dispatch_async(dispatch_get_main_queue()) {
if (error == nil) {
self.updateJSON(data)
}
else {
}
}
}
task!.resume()
}
func updateJSON (data: NSData!) {
let JSONData = (try! NSJSONSerialization.JSONObjectWithData(data, options: []))
TVArray.removeAll(keepCapacity: true)
if let jsonArray = JSONData {
for j in jsonArray {
let title = jsonResult["title"] as! String
let firstAired = jsonResult["first_aired"] as! String
let network = jsonResult["network"] as! String
let channelName = JsonResult["channels"][0]["name"] as! String
let TV = TVInfo(title: title, firstAired: firstAired, network: network, channelName: channelName)
TVArray.append(TV)
}
}
collectionview.reloadData()
}
}
When I use the above code I get an error 'Initializer for conditional binding must have Optional type, not 'AnyObject'' in front of the line 'if let jsonArray = JsonData'. I've tried some methods I've seen on StackOverflow like the method in the link :
[Parsing JSON in swift 2.0
but it didn't work for me. I'm still a bit new to Swift, I really don't want to use SwiftyJSON. Is this the best way to parse this JSON data or is there a better way of doing it?
Since you've used NSJSONSerialization with try! (note the !, meaning it was forced) the value of JSONData is not an optional: you don't have to unwrap it with if let jsonArray = JSONData.
If you still want an optional value, use try? instead.
Otherwise you could also use try inside a do catch block to handle possible errors.
The type of JSONData is unknown, it needs to be known to be an Array for the following for loop.
use:
let JSONData = try! NSJSONSerialization.JSONObjectWithData(data!, options:[]) as! NSArray
You do not need:
if let jsonArray = JSONData {
because you have already crashed if JSONData is nil from the preceding try!
You are better with:
do {
let jsonArray = try NSJSONSerialization.JSONObjectWithData(data!, options:[]) as! NSArray
for j in jsonArray {
// ...
}
} catch {
// handle error
}
Because you have no control over the JSON you receive and crashing because of a server change is not a good idea.
Also really put some time into naming variables, JSONData is not data, it is an array obtained by parsing a JSON string.
Here is a string looks like a json.
let text2 = " [{ \"insertion_date\" :\""+"2015-07-31 11:21:04 +0000"+"\",\"mood\": \""+"Happy"+"\",\"temperature\": \""+"22"+"\"},{ \"insertion_date\" :\""+"2015-07-31 11:21:04 +0000"+"\",\"mood\": \""+"Sad"+"\",\"temperature\": \""+"22"+"\"}]"
I can access the whole string like this.
var data = text2.dataUsingEncoding(NSASCIIStringEncoding, allowLossyConversion: false)
var localError: NSError?
var json3: AnyObject! = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: &localError)
println(json3)
But now I want to access individual element of this string, like - I want to access the second "mood" key, which has the value "Sad".
How can I access it?
You could use something like this:
var jsonArr: NSArray! = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: &localError) as! NSArray
for dict in jsonArr {
print(dict.objectForKey("mood"))
}
Which will print each of the moods.
Swift's native JSON parsing is a pain due to all the optional unwrapping:
if let days = json3 as? NSArray {
if let secondDay = days[1] as? NSDictionary {
let mood = secondDay["mood"] as! String
print(mood)
}
}
You can use other framework like SwiftyJson for an easier time.
You can also use Swift's native types instead of NSArray and NSDictionary, and cast the result of NSJSONSerialization as an array of dictionaries ([[String:AnyObject]]):
if let json3 = NSJSONSerialization.JSONObjectWithData(data!, options: nil, error: &localError) as? [[String:AnyObject]] {
for dict in json3 {
if let mood = dict["mood"] as? String {
println(mood)
}
}
}
Note also that you don't need to give specific options to NSJSONSerialization, you can pass nil in this case.
If you're absolutely certain that your values will always be of type String, you can also cast the result directly (and avoid later casts when accessing values):
if let json3 = NSJSONSerialization.JSONObjectWithData(data!, options: nil, error: &localError) as? [[String:String]] {
for dict in json3 {
if let mood = dict["mood"] {
println(mood)
}
}
}