ObjC URL Query String builder

NSURLComponents+URLQueryEncoding.h

//
//  NSURLComponents+URLQueryEncoding.h
//
//  Created by Willa Drengwitz on 3/8/16.
//  Copyright © 2016 Willa Drengwitz. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface NSURLComponents (URLQueryEncoding)

// TODO: Turn into a computer property to enable 2way street
- (void) queryDictionary:(nullable NSDictionary *)parameters;

@end

NSURLComponents+URLQueryEncoding.m

//
//  NSURLComponents+URLQueryEncoding.h
//
//  Created by Willa Drengwitz on 3/8/16.
//  Copyright © 2016 Willa Drengwitz. All rights reserved.
//

#import "NSURLComponents+URLQueryEncoding.h"

static NSString *__nonnull urlEncode(NSString *__nonnull string) {
    return [string stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
}

// TODO: Upgrade to support NSURLQueryItem(iOS 8.0)
static NSString *__nonnull queryStringFrom(NSDictionary *__nullable parameters) {
    if (parameters == nil) {
        return @"";
    }

    NSMutableArray *pairs = [[NSMutableArray alloc] initWithCapacity:[parameters count]];

    [parameters enumerateKeysAndObjectsUsingBlock:^(NSString *key, id obj, BOOL *stop) {
        NSString *pair = [NSString stringWithFormat:@"%@=%@", urlEncode(key), urlEncode([obj stringValue])];
        [pairs addObject:pair];
    }];

    return [pairs componentsJoinedByString:@"&"];
}

@implementation NSURLComponents (URLQueryEncoding)

- (void) queryDictionary:(nullable NSDictionary *)parameters {
    self.query = queryStringFrom(parameters);
}

@end