(Objective-C) Parse MIME Header Fields

Demonstrates how to parse MIME header fields, including Content-Type, Content-Disposition, and Content-Transfer-Encoding.

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 <NSString.h>

// This example requires 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 http://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 = 0;
part2 = [mime GetPart: [NSNumber numberWithInt: 1]];

// -------------------------------
// Content-Disposition
// -------------------------------
// In this example, the Content-Disposition header field
// contains this value:
// attachment; filename="starfish.gif"

// To get the "filename", call GetHeaderFieldAttribute
// Header field names and attribute names are case insensitive.
NSString *filename = [part2 GetHeaderFieldAttribute: @"Content-Disposition" attrName: @"filename"];
NSLog(@"%@%@",@"Filename: ",filename);

// Because the "filename" is so often accessed, it is also available
// by accessing the "Filename" property:
NSLog(@"%@%@",@"Filename: ",part2.Filename);

// The disposition (without attributes) which in this case 
// is the string "attachment" is accessed via the Disposition property:
NSLog(@"%@%@",@"Disposition: ",part2.Disposition);

// To get the full value of the Content-Disposition header field,
// call GetHeaderField.
NSLog(@"%@%@",@"Content-Disposition: ",[part2 GetHeaderField: @"Content-Disposition"]);

// -------------------------------
// Content-Type
// -------------------------------
// In this example, the Content-Type header field
// contains this value:
// image/gif; name="starfish.gif"

// To get the "name", call GetHeaderFieldAttribute
NSString *name = [part2 GetHeaderFieldAttribute: @"Content-Type" attrName: @"name"];
NSLog(@"%@%@",@"Content-Type name: ",name);

// Because the "name" is so often accessed, it is also available
// by accessing the "Name" property:
NSLog(@"%@%@",@"Content-Type name: ",part2.Name);

// The content-type without attributes is available in the
// ContentType property:
NSLog(@"%@%@",@"Content-Type: ",part2.ContentType);

// To get the full value of the Content-Type header field,
// call GetHeaderField.
NSLog(@"%@%@",@"Content-Type: ",[part2 GetHeaderField: @"Content-Type"]);

// -------------------------------
// Content-Transfer-Encoding
// -------------------------------

// The Encoding property contains the value of the
// Content-Transfer-Encoding property. 
// Calling GetHeaderField("Content-Transfer-Encoding") is
// equivalent to accessing the Encoding property:
NSLog(@"%@%@",@"Content-Transfer-Encoding: ",part2.Encoding);
NSLog(@"%@%@",@"Content-Transfer-Encoding: ",[part2 GetHeaderField: @"Content-Transfer-Encoding"]);

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