The Funny Thing About Old Code…

The funny thing about old code, and most new code, is that there's usually room for improvement. Shortly after posting NSString appendToFile:usingEncoding:, I realized I could've kill two birds with one stone by adding a category method on NSData and then calling that method from the NSString category method. That way I'd get the functionality on both classes without repeating logic.

Without further ado:

#import <Foundation/Foundation.h>

@interface NSData(MCFileAppend)
- (BOOL)appendToFile:(NSString *)path;
@end
@implementation NSData(MCFileAppend)
- (BOOL)appendToFile:(NSString *)path
{
    NSFileHandle *fh = [NSFileHandle fileHandleForWritingAtPath:path]; 
    if (fh == nil)
        return [self writeToFile:path atomically:YES];
    
    [fh truncateFileAtOffset:[fh seekToEndOfFile]];

    [fh writeData:self];
    [fh closeFile];
    return YES;
}
@end
#pragma mark -
@interface NSString(MCFileAppend)
- (BOOL)appendToFile:(NSString *)path usingEncoding:(NSStringEncoding)encoding;
@end
@implementation NSString(MCFileAppend)
- (BOOL)appendToFile:(NSString *)path usingEncoding:(NSStringEncoding)encoding
{
    NSData *encoded = [self dataUsingEncoding:encoding];
    return [encoded appendToFile:path];
}
@end

Posted in: iPhone SDK,Objective-C,Sample Code