A little category to get an NSDictionary from an NSString containing a plist

I really like the plist format. Being able to transform a plist file into a NSDictionary with one line of code really appeals to the lazy guy in me. So when our backend developer asked me what my preferred format for server responses would be, I told him to send his responses in plist format. That’s when I came across a little problem: When accessing the response body of the request, all I got was a NSString. The string contained the plist, but it was still a string and not the usual XML structure that you normally get when you open a plist file.

I found a way to parse a NSString into a NSDictionary on StackOverflow (thanks to Peter N Lewis for his answer).

So I decided to write a little category to extend NSDictionary so that it can initialize a NSDictionary with a plist NSString:

@interface NSDictionary (DictionaryWithString)
   + (NSDictionary *)dictionaryWithString:(NSString *)string;
@end

#import "NSDictionary+DictionaryWithString.h"

@implementation NSDictionary (DictionaryWithString)

+ (NSDictionary *)dictionaryWithString:(NSString *)string {
   NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
   NSString *error;
   NSPropertyListFormat format;
   NSDictionary *dict = [NSPropertyListSerialization 
      propertyListFromData:data 
      mutabilityOption:NSPropertyListImmutable 
      format:&format 
      errorDescription:&error];
   if(!dict){
      NSLog(@"ERROR: could not parse NSString: %@",error);
      [error release];
   }
   return dict;
}

@end

Feel free to use it in your own projects.