@interface URLParser : NSObject

@property (nonatomic, retain) NSArray *variables;
@property (nonatomic, retain) NSArray *keys;

- (id)initWithURLString:(NSString *)url;
- (NSString *)valueForVariable:(NSString *)varName;

@end

@implementation URLParser

- (id) initWithURLString:(NSString *)url{
    self = [super init];
    if (self != nil) {
        NSString *string = url;
        NSScanner *scanner = [NSScanner scannerWithString:string];
        [scanner setCharactersToBeSkipped:
            [NSCharacterSet characterSetWithCharactersInString:@"&?"]];

        NSString *tempString;
        NSMutableArray *keys = [NSMutableArray new];
        NSMutableArray *vars = [NSMutableArray new];

        //ignore the beginning of the string and skip to the vars
        [scanner scanUpToString:@"?" intoString:nil];

        while ([scanner scanUpToString:@"&" intoString:&tempString]) {
            [vars addObject:[tempString copy]];
            
            [keys addObject:
                [[tempString componentsSeparatedByString:@"="]
                    objectAtIndex:0]];
        }
        self.variables = vars;
        self.keys = keys;
    }
    return self;
}

- (NSString *)valueForVariable:(NSString *)varName {
    for (NSString *var in self.variables) {
        if ([var length] > [varName length]+1 &&
            [[var substringWithRange:NSMakeRange(0, [varName length]+1)]
                isEqualToString:[varName stringByAppendingString:@"="]])
        {
            NSString *varValue =
                [var substringFromIndex:[varName length]+1];

            return varValue;
        }
    }
    return nil;
}

- (void) dealloc{
    self.variables = nil;
    self.keys = nil;
}

@end