Objective-C

Access a Part in a Multipart MIME Entity

Demonstrates the Chilkat Mime.PartAt method, which provides live access to the direct child at a zero-based index. The first argument is the index and the second is a Mime object that will reference the child. Modifying it modifies the child stored in the parent tree.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This is how you reach into a multipart message to inspect or edit an individual part — read a part's Content-Type, extract an attachment's body, or change a part in place. The key point is that the returned Mime is a live reference, not a copy, so edits to it flow back into the parent tree. Loop from 0 to NumParts - 1 to visit every direct child.

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Objective-C

#import <CkoMime.h>

BOOL success = NO;

CkoMime *mime = [[CkoMime alloc] init];
success = [mime LoadMimeFile: @"qa_data/multipart_message.eml"];
if (success == NO) {
    NSLog(@"%@",mime.LastErrorText);
    return;
}

//  PartAt provides LIVE access to a direct child part.  The 1st argument is the zero-based index
//  and the 2nd is a Mime object that will reference the child.  Modifying it modifies the child in
//  the parent tree.
int n = [mime.NumParts intValue];
NSLog(@"%@%d",@"Number of parts: ",n);

CkoMime *part = [[CkoMime alloc] init];
int i;
for (i = 0; i <= n - 1; i++) {
    success = [mime PartAt: [NSNumber numberWithInt: i] subPart: part];
    if (success == NO) {
        NSLog(@"%@",mime.LastErrorText);
        return;
    }

    NSLog(@"%@%d%@%@",@"Part ",i,@" Content-Type: ",part.ContentType);
}