Rob Basso Rob Basso - 6 months ago 30
JSON Question

Swift JSON parsing

I am working on an iOS weather app and need some help getting some values with JSON. I am trying to pull the value of id in the weather object. I am getting a value of nil when I debug. Could someone please help me with the logic? Here is the JSON request and Swift code.

{
"coord":{
"lon":138.93,
"lat":34.97
},
"weather":[
{
"id":800,
"main":"Clear",
"description":"clear sky",
"icon":"01n"
}
],
"base":"cmc stations",
"main":{
"temp":292.181,
"pressure":1005.21,
"humidity":100,
"temp_min":292.181,
"temp_max":292.181,
"sea_level":1014.59,
"grnd_level":1005.21
},
"wind":{
"speed":3.41,
"deg":78.0005
},
"clouds":{
"all":0
},
"dt":1464801034,
"sys":{
"message":0.003,
"country":"JP",
"sunrise":1464723086,
"sunset":1464774799
},
"id":1851632,
"name":"Shuzenji",
"cod":200
}


Here is my Swift snippet:

let requestURL: NSURL = NSURL(string: "http://api.openweathermap.org/data/2.5/weather?lat=35&lon=139&appid=6361e893fa064b1bfeaca686cd0929cc")!
let urlRequest: NSMutableURLRequest = NSMutableURLRequest(URL: requestURL)
let session = NSURLSession.sharedSession()
let task = session.dataTaskWithRequest(urlRequest) {
(data, response, error) -> Void in

let httpResponse = response as! NSHTTPURLResponse
let statusCode = httpResponse.statusCode

if (statusCode == 200) {
print("JSON Downloaded Sucessfully.")

do{

let json = try NSJSONSerialization.JSONObjectWithData(data!, options:.AllowFragments)

if let today = json["weather"] as? [[String: AnyObject]] {
//this is pulling 4 key value pairs
for weather in today {

let id = weather["id"] as? String


self.trumpDescription.text=id;
print(id)

}

}
}

catch {
print("Error with Json: \(error)")
}

}
}

task.resume()
}

Answer

try this in your code:
let id = weather["id"]?.stringValue

instead of this:
let id = weather["id"] as? String

And see the magic!

Edit for explanation:
As this answer worked for you, let me tell you why it did.
The id is being sent as integer from the server side. When you do weather["id"] it returns object of type AnyObject?. When you do weather["id"] as? String the casting fails thus you were getting nil.