How to convert nsstring to nsdictionary? - objective-c

Question

I have gone through following question.
Convert NSString to NSDictionary
It is something different then my question.
My question is as follows.
NSString *x=#"<Category_Id>5</Category_Id><Category_Name>Motos</Category_Name><Category_Picture>http://192.168.32.20/idealer/admin/Picture/icon_bike2009819541578.png</Category_Picture>";
Now I want to convert this into a dictionary, something like this,
dictionary key = Category_Id | value = 5
dictionary key = Category_Name | value = ???
dictionary key = Category_Picture | value = ???
I don't know how to perform this.

Answer 1

Not the fastest implementation, but this would do the trick (and doesn’t require any third party libraries):
#interface NSDictionary (DictionaryFromXML)
+ (NSDictionary *)dictionaryFromXML:(NSString *)xml;
#end
#implementation NSDictionary (DictionaryFromXML)
+ (NSDictionary *)dictionaryFromXML:(NSString *)xml
{
// We need to wrap the input in a root element
NSString *x = [NSString stringWithFormat:#"<x>%#</x>", xml];
NSXMLDocument *doc = [[[NSXMLDocument alloc] initWithXMLString:x
options:0
error:NULL]
autorelease];
if (!doc)
return nil;
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for (NSXMLElement *el in [[doc rootElement] children])
[dict setObject:[el stringValue] forKey:[el name]];
return dict;
}
#end

Answer 2

If it's XML then you can use an NSXMLParser. If it's not then you can write your own parser.

Answer 3

You could do it with a regular expression... Something like <([^>]+)>([^<]+)</\1> would grab the key into capture 1 and the value into capture 2. Iterate over the matches and build the dictionary.
This uses RegexKitLite:
NSString * x = #"<Category_Id>5</Category_Id><Category_Name>Motos</Category_Name><Category_Picture>http://192.168.32.20/idealer/admin/Picture/icon_bike2009819541578.png</Category_Picture>";
NSString * regex = #"<([^>]+)>([^<]+)</\\1>";
NSArray * cap = [x arrayOfCaptureComponentsMatchedByRegex:regex];
NSMutableDictionary * d = [NSMutableDictionary dictionary];
for (NSArray * captures in cap) {
if ([captures count] < 3) { continue; }
NSString * key = [captures objectAtIndex:1];
NSString * value = [captures objectAtIndex:2];
[d setObject:value forKey:key];
}
NSLog(#"%#", d);