Thursday, 17 July 2014

iOS Design Patterns 1/2

iOS Design Patterns – you’ve probably heard the term, but do you know what it means? While most developers probably agree that design patterns are very important, there aren’t many articles on the subject and we developers sometimes don’t pay too much attention to design patterns while writing code.



Tuesday, 1 April 2014

how to check file is updated or not without using modified time

how to check file is updated or not without using modified time  in cocoa for mac-osx objective-c

How to get checkSum of a file........




#import "NSData+MD5.h"

@interface NSData(MD5)
 - (NSString *)MD5;


@end



#import <CommonCrypto/CommonDigest.h>
 @implementation NSData(MD5)

- (NSString*)MD5
{
  // Create byte array of unsigned chars
  unsigned char md5Buffer[CC_MD5_DIGEST_LENGTH];

// Create 16 byte MD5 hash value, store in buffer
  CC_MD5(self.bytes, self.length, md5Buffer);
    
// Convert unsigned char buffer to NSString of hex values
  NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
  for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) 
[output appendFormat:@"%02x",md5Buffer[i]];

  return output;
}


@end




Call from Own class: 

+(NSString *)getCheckSum:(NSString *)filePath{
     NSData *nsData = [NSData dataWithContentsOfFile:filePath];
     if (nsData){
         return [nsData MD5];
     }
    else{
         return nil;
     }
}