URLByModifyingParameters

gistfile1.txt

#import <Foundation/Foundation.h>

NSString *decodeStringFromURLFormat(NSString *string)
{
    NSString *result = [string stringByReplacingOccurrencesOfString:@"+" withString:@" "];
    result = [result stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    return result;
}

NSString *encodeStringToURLFormat(NSString *string)
{
    NSString *result = [string stringByReplacingOccurrencesOfString:@" " withString:@"+"];
    result = [result stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    return result;
}


NSDictionary *dictionaryFromQuery(NSString *query)
{
    NSMutableDictionary *queryDict = nil;
    NSArray *urlComponents = [query componentsSeparatedByString:@"&"];
    
    for (NSString *keyValuePair in urlComponents)
    {
        NSRange equalsSignRange = [keyValuePair rangeOfString:@"="];
        if (equalsSignRange.location != NSNotFound)
        {
            NSString *key = [keyValuePair substringToIndex:equalsSignRange.location];
            NSString *value = decodeStringFromURLFormat([keyValuePair substringFromIndex:equalsSignRange.location + equalsSignRange.length]);
            
            NSMutableArray *valuesArray = [queryDict objectForKey:key];
            if(!valuesArray)
            {
                valuesArray = [NSMutableArray new];
                if (!queryDict)
                {
                    queryDict = [NSMutableDictionary new];
                }
                queryDict[key] = valuesArray;
            }
            [valuesArray addObject:value];
        }
    }
    return [queryDict copy];
}

NSString *stringFromQueryDictionary(NSDictionary *dict)
{
    NSMutableString *string = [NSMutableString new];
    for (NSString *key in dict.allKeys)
    {
        id value = dict[key];
        if ([value isKindOfClass:[NSArray class]])
        {
            for (NSString *itVal in value)
            {
                NSString *valString = encodeStringToURLFormat(itVal);
                if (!string.length)
                    [string appendFormat:@"%@=%@", key, valString];
                else
                    [string appendFormat:@"&%@=%@", key, valString];
            }
        }
        else
        {
            NSString *valString = encodeStringToURLFormat(value);
            if (!string.length)
                [string appendFormat:@"%@=%@", key, valString];
            else
                [string appendFormat:@"&%@=%@", key, valString];
        }
    }
    return [string copy];
}

NSURL *URLByModifyingParameters(NSURL *url, void (^block)(NSMutableDictionary *parameters))
{
    NSString *query = url.query;
    
    if (!block || !query)
    {
        return url;
    }

    NSURL *changedUrl = url;
    NSMutableDictionary *queryDict = [[NSMutableDictionary alloc] initWithDictionary:dictionaryFromQuery(query)];
    if (queryDict.allKeys.count > 0)
    {
        block(queryDict);
        NSString *changedQuery = stringFromQueryDictionary(queryDict);
        
        NSString *urlWithoutQuery = [url.absoluteString substringToIndex:url.absoluteString.length - query.length];
        changedUrl = [NSURL URLWithString:[NSString stringWithFormat:@"%@%@", urlWithoutQuery, changedQuery]];
    }
    
    return changedUrl;
}

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        NSURL *url = [NSURL URLWithString:@"https://market.yandex.ru/catalog/54954/list?hid=237420&glfilter=7893318%3A152709%2C152970%2C152858&local-offers-first=0&deliveryincluded=0&onstock=1"];
        NSURL *urlModified = URLByModifyingParameters(url, ^(NSMutableDictionary *parameters) {
            for (NSString *key in parameters.allKeys)
            {
                parameters[key] = @"1234";
            }
        });
        NSLog(@"%@\n%@", url, urlModified);
    }
    return 0;
}