URL encoding GET requests

[jasperblues]

Thankfully RESTful style parameter passing is popular now, but every now and then we need to hit a legacy service, where we append traditional query parameters to a GET request.

This is actually fairly complicated.

• There are no special helper tools provided in the standard Cococa APIs . .
• . . except for one fairly low level method, that unfortunately doesn't handle the slash '/' character properly.

It would be nice if we could create a request something like this:

STHTTPRequest *request = [STHTTPRequest requestWithURL:_endpointUrl 
    appendedWithQueryParameters:@{
        @"q" : city,
        @"format" : @"json",
        @"num_of_days" : [NSString stringWithFormat:@"%i", _daysToRetrieve],
        @"key"         : _apiKey
    }];
];

The code that I currently use for encoding URLs looks like this:

Utility class:

+ (NSURL *)URL:(NSURL *)url appendedWithQueryParameters:(NSDictionary *)parameters
{
    NSMutableString *urlString = [[NSMutableString alloc] initWithString:[url absoluteString]];

    for (id key in parameters) {
        NSString *keyString = [key description];
        NSString *valueString = [[parameters objectForKey:key] description];

        if ([urlString rangeOfString:@"?"].location == NSNotFound) {
            [urlString appendFormat:@"?%@=%@", [self URLEscapeString:keyString], [self URLEscapeString:valueString]];
        }
        else {
            [urlString appendFormat:@"&%@=%@", [self URLEscapeString:keyString], [self URLEscapeString:valueString]];
        }
    }
    return [NSURL URLWithString:urlString];
}

//Fall all the way down to foundation, as it handles '/' character properly
+ (NSString *)URLEscapeString:(NSString *)rawString
{
    CFStringRef originalStringRef = (__bridge_retained CFStringRef) rawString;
    NSString *encoded =
        (__bridge_transfer NSString *) CFURLCreateStringByAddingPercentEscapes(NULL, originalStringRef, NULL, NULL, kCFStringEncodingUTF8);
    CFRelease(originalStringRef);
    return encoded;
}

[jasperblues]

Alternatively we could use: [request addQueryParameterWithName:value]

I love that this library is simple and not bloated, however I think this would be a useful addition. If you like I could send a pull request.

[gavinwilliams]

+1

[nst]

Thank you for the proposal, I'll review it in the upcoming days.

[nst]

Sorry for the delay, I've been quite busy lately, I haven't forgotten you proposal.

[nst]

I eventually chose to use a GETDictionary property.

I hope you'll find it useful.