Categorizing Facebook Likes into an NSMutableDictionary

categorizeLikes.m

/*
This method takes a NSDictionary of likes returned by facebook and returns an NSMutableDictionary of NSArrays, where
each key in the dictionary corresponds with a "category"

 For example: 
    { 
        "company": [{} , {} , {} ], 
        "song": [ {} , {} ] 
    } 
 
 */
- (void) categorizeLikes:(NSDictionary *)likesData {
    NSArray *allLikes = (NSArray *)[likesData objectForKey:@"data"];
    
    NSMutableDictionary *sortedLikes = [NSMutableDictionary dictionary];
    NSMutableArray *tempArray = [NSMutableArray arrayWithArray:allLikes];
    
    for (likes in tempArray) {        
        NSString *catKey = [likes objectForKey:@"category"];
        
        //If the dictionary already has this category defined, then there is a NSMutableArray inside it
        //and we can just push this object into that array
        if ([sortedLikes objectForKey:catKey] != nil) {
            [[sortedLikes objectForKey:catKey] addObject:likes];
        }
        
        //Otherwise, if the dictionary does not have this category defined,
        //we must create a NSMutableArray and add it to this category with that object inside it.
        else {
            NSMutableArray *catArray = [NSMutableArray arrayWithObject:likes];
            [sortedLikes setObject:catArray forKey:catKey];
        }
        
    }
    
    self.likes = sortedLikes;
}