How to create this JSON Object in Swift - ios

Question

I have this JSON file which I want to create and send to a server. I am new to using JSON so please can someone guide me how can I create this Object ?
{
"today_steps": 5663,
"activities": [{
"activity_name": "Walking",
"start_datetime": "2016-07-03 10:03AM",
"activity_duration": 2768000,
"steps": 1362,
"average_heart": 96,
"calories": 109
}, {
"activity_name": "Running",
"start_datetime": "2016-07-03 02:45PM",
"activity_duration": 1768000,
"steps": 2013,
"average_heart": 112,
"calories": 271
}],
"workout": []
}

Answer 1

Try code
Swift 2
let activities = [["activity_name":"Walking",
"start_datetime":"2016-07-03 10:03AM",
"activity_duration":2768000,
"steps":1362,
"average_heart":96,
"calories":109],
["activity_name":"Running",
"start_datetime":"2016-07-03 02:45PM",
"activity_duration":1768000,
"steps":2013,
"average_heart":112,
"calories":271]]
let dictionary = ["today_steps":5663,
"activities":activities,
"workout":[]
]
print(dictionary)
do {
let jsonData = try NSJSONSerialization.dataWithJSONObject(dictionary, options: NSJSONWritingOptions.PrettyPrinted)
// here "jsonData" is the dictionary encoded in JSON data
} catch let error as NSError {
print(error)
}
Swift3
change convert dictionary to Json by
let jsonData = try JSONSerialization.data(withJSONObject: dictionary, options: .prettyPrinted)

Answer 2

You don't always need to create an object to send it to server. You can also create a request with the required headers and you can send it as a string.
Take a look at this library and its documentation.
https://github.com/Alamofire/Alamofire
You can also send NSDictionary and this library will convert that to a JSON object.
An example from their github.
let parameters = [
"foo": [1,2,3],
"bar": [
"baz": "qux"
] ]
Alamofire.request(.POST, "https://httpbin.org/post", parameters: parameters, encoding: .JSON)
// HTTP body: {"foo": [1, 2, 3], "bar": {"baz": "qux"}}

Answer 3

Try use this
let json = [
"today_steps": 5663,
"activities": [[
"activity_name": "Walking",
"start_datetime": "2016-07-03 10:03AM",
"activity_duration": 2768000,
"steps": 1362,
"average_heart": 96,
"calories": 109
], [
"activity_name": "Running",
"start_datetime": "2016-07-03 02:45PM",
"activity_duration": 1768000,
"steps": 2013,
"average_heart": 112,
"calories": 271
]],
"workout": []
]

Answer 4

You can go ahead and use the NSJSONSerialization class to convert the data to an object that can be later be parsed.
A method like the following can always be used.
// Given raw JSON, return a usable Foundation object
private func convertDataWithCompletionHandler(data: NSData, completionHandlerForConvertData: (result: AnyObject!, error: NSError?) -> Void) {
var parsedResult: AnyObject!
do {
parsedResult = try NSJSONSerialization.JSONObjectWithData(data, options: .AllowFragments)
} catch {
let userInfo = [NSLocalizedDescriptionKey : "Could not parse the data as JSON: '\(data)'"]
completionHandlerForConvertData(result: nil, error: NSError(domain: "convertDataWithCompletionHandler", code: 1, userInfo: userInfo))
}
completionHandlerForConvertData(result: parsedResult, error: nil)
}
Pass the JSON result given by the api call to this method.