Butloads of Categories

NSArray+firstObject.h

//
//  NSArray+firstObject.h
//
//  Created by Pontus Carlsson on 2013-10-02.
//

#import <Foundation/Foundation.h>

@interface NSArray (firstObject)

- (id)firstObject;

@end

NSArray+firstObject.m

//
//  NSArray+firstObject.m
//
//  Created by Pontus Carlsson on 2013-10-02.
//

#import "NSArray+firstObject.h"

@implementation NSArray (firstObject)

- (id)firstObject
{
    id object = nil;
    
    if (self.count > 0) {
        object = [self objectAtIndex:0];
    }
    
    return object;
}

@end

NSString+URLEncoding.h

//
//  NSString+URLEncoding.h
//
//  Created by Pontus Carlsson on 2013-09-25.
//

#import <Foundation/Foundation.h>

@interface NSString (URLEncoding)

- (NSString *)URLEncode;
- (NSString *)URLEncodeWithEncoding:(NSStringEncoding)encoding;

@end

NSString+URLEncoding.m

//
//  NSString+URLEncoding.m
//
//  Created by Pontus Carlsson on 2013-09-25.
//

#import "NSString+URLEncoding.h"

@implementation NSString (URLEncoding)

NSStringEncoding defaultEncoding = NSUTF8StringEncoding;
NSString *escapedCharacters = @"!*'\"();:@&=+$,/?%#[]% ";

- (NSString *)URLEncode
{
    return [self URLEncodeWithEncoding:defaultEncoding];
}

- (NSString *)URLEncodeWithEncoding:(NSStringEncoding)encoding
{
    CFStringRef selfReference = (__bridge CFStringRef)self;
    CFStringRef escapedCharactersReference = (__bridge CFStringRef)escapedCharacters;

    return (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(nil, selfReference, nil, escapedCharactersReference,
                                         CFStringConvertNSStringEncodingToEncoding(encoding)));
}

@end