How to parse nested JSON objects?

Question

I get the JSON format like this:

stream( { posts: [{CHANNEL: {ios: "(format=m3u8-aapl).m3u8"} }]})

What I want to get is an array for the "ios". This is my code:

id jsonObjects = [NSJSONSerialization JSONObjectWithData:
                  jsonSource options:NSJSONReadingMutableContainers error:nil];
for (NSDictionary *dataDict in jsonObjects) {
    NSArray *ios_data = [[[dataDict objectForKey:@"posts"] objectForKey:@"CHANNEL"] objectForKey:@"ios"];
    NSLog(@"%@",ios_data);
    dict = [NSDictionary dictionaryWithObjectsAndKeys:ios_data, ios,nil];

}

but it return in NULL, what the problem of it?

Answer 1

Your "JSON":

stream( { posts: [{CHANNEL: {ios: "(format=m3u8-aapl).m3u8"} }]})

Is not JSON. You can try running it through a validator like http://jsonlint.com/ to test it out.

Also, you should create an NSError reference to pass in instead of nil so NSJSONSerialization can vend you an error object. This will help in your debugging.

---

Here is an example of what your data would look like if it were valid JSON:

{
    "stream": [
        {
            "posts": [
                {
                    "CHANNEL": {
                        "ios": "(format=m3u8-aapl).m3u8"
                    }
                }
            ]
        }
    ]
}

(I spaced it out to be more legible, but the spacing is unnecessary for parsing.)

Answer 2

Once you have your array holding 'posts' you can drill down like this:

NSArray *fileData = [myDic1 valueForKeyPath:@"posts.CHANNEL"];

and then access like this:

for (int i=0; i < [clientFileData count]; i++) {
NSDictionary *myDictionary = [fileData objectAtIndex:i];
]

Also, unless I am wrong, your JSON file seems incorrectly formatted.

Answer 3

Get your response like:

NSDictionary *dictionaryData = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];

Correct JSOn should be like this

{
   "posts":[
      {
         "CHANNEL":{
            "ios":"(format=m3u8-aapl).m3u8"
         }
      }
   ]
}

Get the correct format of JSON and then try to parse it. And one thing you were doing wrong is POST is an array.