ios - Storing fetched json dictionaries in array resulting in nil -

i have database of files attributes such url, title, , timestamp. when load view controller, i'm fetching file data , loading tableview. because there multiple files each 3 attributes, i'm trying save data in array, go through each object in array , extract json data. of now, request , response successful, array remains nil. approach wrong?

 let task = session.datataskwithrequest(request, completionhandler: {data, response, error -> void in          guard let data = data, response = response else         {             print("no data or response!")             return         }          let strdata = nsstring(data: data, encoding: nsutf8stringencoding)         print("body: \(strdata)", terminator: "")          {             self.fetchedarray = try nsjsonserialization.jsonobjectwithdata(data, options: .mutableleaves) as? nsarray               print("fetched array count %i \(self.fetchedarray!.count)")               if let jsonarray: nsarray = self.fetchedarray{                   var = 0; i<jsonarray.count; ++i {                       let dictresult = jsonarray.objectatindex(i) as! nsdictionary                      let recording = recordings()                     recording.trackurl = dictresult["url"] as? string                     recording.tracktimestamp = dictresult["timestamp"] as? string                     recording.trackauthor = dictresult["author"] as? string                     recording.tracktitle = dictresult["title"] as? string                     self.recordings?.addobject(recording)                      }             }             else             {                 // no error thrown, not nsdictionary                 let jsonstr = nsstring(data: data, encoding: nsutf8stringencoding)                 print("no error thrown not parse json: '\(jsonstr)'")             }         }         catch let parseerror {             // log error thrown `jsonobjectwithdata`             print(parseerror)             let jsonstr = nsstring(data: data, encoding: nsutf8stringencoding)             print("error thrown. not parse json: '\(jsonstr)'")         }     })      task.resume() 

as executing second last else statement print("no error thrown not parse json: '\(jsonstr)'") , printing out data.

log of data before serialization:

response: <nshttpurlresponse: 0x7c349990> { url: http://127.0.0.1:5000/auth/serve_current_user_files } { status code: 200, headers { "content-length" = 239; "content-type" = "application/json"; date = "sat, 03 oct 2015 02:53:00 gmt"; server = "werkzeug/0.10.4 python/2.7.10"; "set-cookie" = "session=eyjfznjlc2gionrydwusil9pzci6eyigyii6ik16rxhargs0tldvm1luqmxnrejrwlrnefpqz3pzmkl3t1drne5ezzvprek9in0sinvzzxjfawqioiixin0.cpduja.mm56vpuzpiokczvorw7x2ysz960; httponly; path=/"; } }body: optional({   "recordings": [   {   "author": 1,    "timestamp": "sun, 27 sep 2015 17:44:54 gmt",    "title": "test1.m4a",    "url": "/users/allahesharghi/desktop/omid/pythonprojects/sound/sound/uploads/omid1/test1.m4a" } ] 

your json is:

{     "recordings": [         {             "author": 1,             "timestamp": "sun, 27 sep 2015 17:44:54 gmt",             "title": "test1.m4a",             "url": "/users/allahesharghi/desktop/omid/pythonprojects/sound/sound/uploads/omid1/test1.m4a"         }     ] } 

so, root object isn't array, dictionary array of dictionaries key recordings. means when say

self.fetchedarray = try nsjsonserialization.jsonobjectwithdata(data, options: .mutableleaves) as? nsarray 

self.fetchedarray nil because downcast nsarray fail, because nsdictionary can't downcast nsarray.

you need access root dictionary , access array recordings key -

do {        somedictionary = try nsjsonserialization.jsonobjectwithdata(data, options: .mutableleaves) as? nsdictionary        self.fetchedarray = somedictionary!["results"] as? nsarray             print("fetched array count %i \(self.fetchedarray!.count)") ...