Re: Base64 encoding

[Pete French]

> Is there any cocoa class which convert NSString or NSData to
> Base64encoding ?

grossly inefficient, but does the job for me...



- (PFString*)base64Representation
{
        char *base64array =
            "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        PFString *retval = [PFString stringWithString:@""];
        PFAutoreleasePool *pool = [PFAutoreleasePool new];
        int bytesLeft = 0;
        unsigned char *dataPtr = NULL;

        dataPtr = [self bytes];
        bytesLeft = [self length];
        for(;bytesLeft>0;) {
                char to_add[16];
                unsigned int dataWord = 0;
                int i;

                /* make the data word */
                for(i=0;i<3;i++) {
                        dataWord = dataWord << 8;
                        if(bytesLeft > 0)
                                dataWord = dataWord | *dataPtr++;
                        bytesLeft--;
                }

                /* create the array */
                for(i=3;i>=0;i--) {
                        unsigned int thisIndex = dataWord & 0x3f;
                        dataWord = dataWord >> 6;
                        to_add[i] = base64array[thisIndex];
                }

                /* finish it off */
                to_add[4] = '\0';
                switch(bytesLeft) {
                        case -2:
                                to_add[2] = '=';
                        case -1:
                                to_add[3] = '=';
                        case 0:
                                break;
                }

                /* add it */
                [retval appendFormat:@"%s", to_add];
        }

        /* tidy up and release */
        [pool release];
        return retval;
}