How do I get the value's of name & url from a nsdictionary object?

Question

So i'm using touch JSON which worked out pretty well for me. I was able to take an array, put it in a dictionary, serialize it via touchJSON and send it out via http.

now on the return end, i received the data, and put it into a dictionary (i'm using trends.json from twitter as an example JSON).

now if i try to get the value for trends from the dictionary object, i get this http://cl.ly/fe270fe7f05a0ea8d478

If I try to get the value for name or URL, I get nothing which is frustrating. That is the data I will need. You can tell it is in a dictionary format because it is formatted and it is reading properly sort of for trends. I'm pretty sure I'm missing something, so please let me know which direction to follow.

---

Here is the code:

// this is all touch JSON magic. responseString has the full contents of trends.json

 NSString *response = [request responseString];
 NSLog(@"response value is:%@",response);

 NSString *jsonString = response;
 NSData *jsonData = [jsonString dataUsingEncoding:NSUTF32BigEndianStringEncoding];
 NSError *error = nil;
 NSDictionary *dictionary = [[CJSONDeserializer deserializer] deserializeAsDictionary:jsonData error:&error];
//end of touchJSON.  It is in a dictionary now.


 NSLog(@"dictionary:%@, error %@", dictionary, error); //http://cl.ly/adb6c6a974c3e70fb51c

 NSString *twitterTrends = (NSString *) [dictionary objectForKey:@"trends"];
 NSLog(@"ANSWER:%@",twitterTrends); //http://cl.ly/fe270fe7f05a0ea8d478

Answer 1

You've only got as far as extracting the array of dictionaries. (The response has a dictionary inside an array inside a dictionary.)

You need to extract each dictionary from the array, then lookup the name and url entries in that dictionary.

Something like this should print the first entry:

NSArray *twitterTrends = [dictionary objectForKey:@"trends"];
NSDictionary *entry1 = [twitterTrends objectAtIndex:0];
NSLog(@"entry1: %@, %@", [entry1 objectForKey:@"name"], [entry1 objectForKey:@"url"]);

(Code has not been tested so may not compile straight off!)

Answer 2

When you use print an object using a formatstring %@ you will infact get the output of the description message send to the object. For a NSDictionary this output looks very similar to unparsed JSON, but it is not a string, it's an object graph of NSDictionaries, NSArrays, NSStrings, NSNumbers and NSDates.

So want you have in twitterTrends an NSArray of NSDictionaries. To get the parts just enumerate the Array.

for (NSDictionary* trend in twitterTrends) {
    NSString* url = [trend objectForKey:@"url"];
    NSString* name = [trend objectForKey:@"name"];
}

Or you may access a trend by its index:

[[twitterTrends objectAtIndex:5] objectForKey:@"url"];