How to convert UTF8String to JSON based NSDictionary? - ios

Question

I am getting one of my web-service response in JSON. Here is the UTF8String base responseString:
"{\"ApplicationId\":1,\"CurrentPosition\":0,\"EndOfFile\":false,\"Media\":{\"Active\":true,\"Description\":\"This video demonstrates a quick overview of Bentley LEARN Server.\",\"LocationId\":1,\"MP4URL\":\"http:\\/\\/cdnllnw.bentley.com\\/s\\/LearnVideo\\/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a\",\"MediaId\":5003235,\"MediaURL\":\"http:\\/\\/cdnllnw.bentley.com\\/s\\/LearnVideo\\/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a\",\"StreamServer\":null,\"Title\":\"Welcome\",\"TransferStatus\":0,\"filesize\":9094429},\"MediaDuration\":0,\"SkippedCurrentPosition\":0,\"UserBP\":8011512,\"ViewedTime\":0}"
After formatting it looks like:
{
"ApplicationId":1,
"CurrentPosition":0,
"EndOfFile":false,
"Media":
{
"Active":true,
"Description":"This video demonstrates a quick overview of Bentley LEARN Server.",
"LocationId":1,
"MP4URL":"http:\/\/cdnllnw.bentley.com\/s\/LearnVideo\/Welcome.mp4?s=1380035311&e=1380078511&h=d8de8ade046266fb7324be90a575f978",
"MediaId":5003235,
"MediaURL":"http:\/\/cdnllnw.bentley.com\/s\/LearnVideo\/Welcome.mp4?s=1380035311&e=1380078511&h=d8de8ade046266fb7324be90a575f978",
"StreamServer":null,
"Title":"Welcome",
"TransferStatus":0,
"filesize":9094429
},
"MediaDuration":0,
"SkippedCurrentPosition":0,
"UserBP":8011512,
"ViewedTime":0
}
How can I convert this string into JSON object or NSDictionary object so that I can access all key-values easily.
I have tried this:
NSString *responseString = [NSString stringWithUTF8String:response.c_str()];
NSDictionary *JSONdict =
[NSJSONSerialization JSONObjectWithData: [responseString dataUsingEncoding:NSUTF8StringEncoding]
options: NSJSONReadingMutableContainers
error: &error];
But it says JSONdict is nil and error description is:
Error Domain=NSCocoaErrorDomain Code=3840 "The operation couldn’t be completed. (Cocoa error 3840.)" (JSON text did not start with array or object and option to allow fragments not set.) UserInfo=0xd8bbd30 {NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}
Please help

Answer 1

Adding NSJSONReadingAllowFragments as option should help according to error:
NSString* jsonString = #"{\"ApplicationId\":1,\"CurrentPosition\":0,\"EndOfFile\":false,\"Media\":{\"Active\":true,\"Description\":\"This video demonstrates a quick overview of Bentley LEARN Server.\",\"LocationId\":1,\"MP4URL\":\"http:\\/\\/cdnllnw.bentley.com\\/s\\/LearnVideo\\/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a\",\"MediaId\":5003235,\"MediaURL\":\"http:\\/\\/cdnllnw.bentley.com\\/s\\/LearnVideo\\/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a\",\"StreamServer\":null,\"Title\":\"Welcome\",\"TransferStatus\":0,\"filesize\":9094429},\"MediaDuration\":0,\"SkippedCurrentPosition\":0,\"UserBP\":8011512,\"ViewedTime\":0}";
NSError* error = nil;
NSDictionary *JSONdict =
[NSJSONSerialization JSONObjectWithData: [responseString dataUsingEncoding:NSUTF8StringEncoding]
options: NSJSONReadingMutableContainers | NSJSONReadingAllowFragments
error: &error];
But that means the NSString you pasted in your question contains extra characters which are not following JSON format. If you add more code from where you take this value (file, web) - I can help more to make it valid. Until then treat this answer as workaround :)
The properly formatted string should be:
{\"ApplicationId\":1,\"CurrentPosition\":0,\"EndOfFile\":false,\"Media\":{\"Active\":true,\"Description\":\"This video demonstrates a quick overview of Bentley LEARN Server.\",\"LocationId\":1,\"MP4URL\":\"http:\\/\\/cdnllnw.bentley.com\\/s\\/LearnVideo\\/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a\",\"MediaId\":5003235,\"MediaURL\":\"http:\\/\\/cdnllnw.bentley.com\\/s\\/LearnVideo\\/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a\",\"StreamServer\":null,\"Title\":\"Welcome\",\"TransferStatus\":0,\"filesize\":9094429},\"MediaDuration\":0,\"SkippedCurrentPosition\":0,\"UserBP\":8011512,\"ViewedTime\":0}
Without " at the beggining and at the end. Maybe that's the reason.
If you are loading this from web - make sure you don't have any JS included or extra headers and confirm that your web service responds with JSON format in headers.

Answer 2

I've try your NSString with the next piece of code (it's a starting point) to output the dictionary from "Media";
NSString *string = #"{\"ApplicationId\":1,\"CurrentPosition\":0,\"EndOfFile\":false,\"Media\":{\"Active\":true,\"Description\":\"This video demonstrates a quick overview of Bentley LEARN Server.\",\"LocationId\":1,\"MP4URL\":\"http:\\/\\/cdnllnw.bentley.com\\/s\\/LearnVideo\\/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a\",\"MediaId\":5003235,\"MediaURL\":\"http:\\/\\/cdnllnw.bentley.com\\/s\\/LearnVideo\\/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a\",\"StreamServer\":null,\"Title\":\"Welcome\",\"TransferStatus\":0,\"filesize\":9094429},\"MediaDuration\":0,\"SkippedCurrentPosition\":0,\"UserBP\":8011512,\"ViewedTime\":0}";
NSString *newString = [string stringByReplacingOccurrencesOfString:#"\\" withString:#""];
NSDictionary *dictionary = [NSJSONSerialization JSONObjectWithData:[newString dataUsingEncoding:NSUTF8StringEncoding] options:NSJSONReadingMutableLeaves error:nil];
NSLog(#"%#", [dictionary valueForKey:#"Media"]);
And the result is:
{
Active = 1;
Description = "This video demonstrates a quick overview of Bentley LEARN Server.";
LocationId = 1;
MP4URL = "http://cdnllnw.bentley.com/s/LearnVideo/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a";
MediaId = 5003235;
MediaURL = "http://cdnllnw.bentley.com/s/LearnVideo/Welcome.mp4?s=1380034262&e=1380077462&h=c2641922fd862ffe5c5a05e94786359a";
StreamServer = "<null>";
Title = Welcome;
TransferStatus = 0;
filesize = 9094429;
}
Hope it will be useful for you.