URL-Encode NSStrings and NSDictionaries.

URLEncode.m

// From Cocoanetics (s/&amp/&)
static NSString *NSStringURLEncode(NSString *string) {
	return [(NSString *)CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)string, NULL, CFSTR("!*'();:@&;=+$,/?%#[]"), kCFStringEncodingUTF8) autorelease];
}

static NSString *NSDictionaryURLEncode(NSDictionary *dict) {
	NSMutableString *ret = [NSMutableString string];
	
	NSArray *allKeys = [dict allKeys];
	for (NSString *key in allKeys) {
		[ret appendString:NSStringURLEncode(key)];
		[ret appendString:@"="];
		[ret appendString:NSStringURLEncode([dict objectForKey:key])];
		[ret appendString:@"&"];
	}
	
	return [ret substringToIndex:[ret length]-1];
}