Encoding string arguments for URLs

Question

I created a method to build URLs for me.

- (NSString *)urlFor:(NSString *)path arguments:(NSDictionary *)args
{
    NSString *format = @\"http://api.example.com/         


        

Answer 1

IIRC, slashes should be interpreted properly when they're in the query part of a URL. Did you test to see if it still works without encoded slashses? Otherwise, do something like:

if ([args isKindOfClass:[NSDictionary class]]) {
        for (NSString *key in [args allKeys]) {
            NSString *value = [(NSString*)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)[args objectForKey:key], NULL, CFSTR("/?&:=#"), kCFStringEncodingUTF8) autorelease];
            [url appendString:[NSString stringWithFormat:@"&%@=%@", key, value]];
            [value release];
        }
}

return url;

Note the value of the 4th argument to CFURLCreateStringByAddingPercentEscapes.

Answer 2

I'd recommend our KSFileUtilities set of classes. Your example would then be:

- (NSString *)urlFor:(NSString *)path arguments:(NSDictionary *)args
{
    NSMutableDictionary *parameters = [NSMutableDictionary dictionaryWithDictionary:args];
    [parameters setObject:@"2.0.1" forKey:@"version"];

    NSURL *result = [NSURL ks_URLWithScheme:@"http"
                                       host:@"api.example.com"
                                       path:path
                            queryParameters:parameters;

    return [result absoluteString];
}

Answer 3

You should consider using Google Toolbox for Mac's GTMNSString+URLArguments; it's designed for exactly this purpose.