(Objective-C) Parse MIME to get Binary Data (such as GIF, JPG, or any binary file)

Demonstrates how to parse a MIME to get binary data. This example extracts the image data for a GIF image to an in-memory byte array, and also to a file.

This example uses a MIME test file located at http://www.chilkatsoft.com/testData/sampleMime2.txt. It contains the following MIME:

Content-Type: multipart/mixed;
 boundary="------------080707010302060306060800";

This is a multi-part message in MIME format.

--------------080707010302060306060800
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

This is the plain-text body.
--------------080707010302060306060800
Content-Disposition: attachment; filename="starfish.gif";
Content-Transfer-Encoding: base64
Content-Type: image/gif; name="starfish.gif";

R0lGODlhIAAgAPcAAP///+/v7/f39+/n5/fv7//39/fn597OzufW1tbGxs69vffe3u/W1salpZQQ
EIQYEJwQCJQYCJwYCM6clL2Ee5wpGIwhEK0YANatpdalnHMYCKUhCJQYAKUYAM6Ec5QhCJwhCPfW
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--------------080707010302060306060800--

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoMime.h>
#import <CkoFileAccess.h>

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

CkoMime *mime = [[CkoMime alloc] init];

// Load the sampleMime2.txt file into the MIME object.
// (This file is available at https://www.chilkatsoft.com/testData/sampleMime2.txt )

BOOL success = [mime LoadMimeFile: @"sampleMime2.txt"];
if (success == NO) {
    NSLog(@"%@",mime.LastErrorText);
    return;
}

// The GIF image is the 2nd sub-part located directly under the
// top-level MIME node.  Indexing begins at 0, therefore the 2nd
// sub-part is at index 1.
CkoMime *part2 = [mime GetPart: [NSNumber numberWithInt: 1]];

NSData binaryData;

// The GetBodyBinary method returns the binary bytes
// of the part's body, automatically decoded from whatever
// content-transfer-encoding might be used (such as base64).
binaryData = [part2 GetBodyBinary];

// We now have the binary bytes of the GIF image in binaryData.
// Save it to a file.
CkoFileAccess *fac = [[CkoFileAccess alloc] init];
success = [fac WriteEntireFile: @"out1.gif" fileData: binaryData];
if (success != YES) {
    NSLog(@"%@",fac.LastErrorText);
    return;
}

// An easier way to save the body content to a file,
// assuming your application does not need to access
// the binary data in-memory, is to call SaveBody
success = [part2 SaveBody: @"out2.gif"];
if (success == NO) {
    NSLog(@"%@",part2.LastErrorText);
    return;
}

NSLog(@"%@",@"Finished.");