Objective-C: How to add query parameter to NSURL?

Question

Let\'s say I have an NSURL? Whether or not it already has an empty query string, how do I add one or more parameters to the query of the NSUR

Answer 1

Here's an implementation that passes your specs:

@implementation NSURL (Additions)

- (NSURL *)URLByAppendingQueryString:(NSString *)queryString {
    if (![queryString length]) {
        return self;
    }

    NSString *URLString = [[NSString alloc] initWithFormat:@"%@%@%@", [self absoluteString],
                           [self query] ? @"&" : @"?", queryString];
    NSURL *theURL = [NSURL URLWithString:URLString];
    [URLString release];
    return theURL;
}

@end

And here is an implementation for NSString:

@implementation NSString (Additions)

- (NSURL *)URLByAppendingQueryString:(NSString *)queryString {
    if (![queryString length]) {
        return [NSURL URLWithString:self];
    }

    NSString *URLString = [[NSString alloc] initWithFormat:@"%@%@%@", self,
                           [self rangeOfString:@"?"].length > 0 ? @"&" : @"?", queryString];
    NSURL *theURL = [NSURL URLWithString:URLString];
    [URLString release];
    return theURL;
}

// Or:

- (NSString *)URLStringByAppendingQueryString:(NSString *)queryString {
    if (![queryString length]) {
        return self;
    }
    return [NSString stringWithFormat:@"%@%@%@", self,
            [self rangeOfString:@"?"].length > 0 ? @"&" : @"?", queryString];
}

@end