(Objective-C) MIME Content-Disposition Header Field

Explains the Content-Disposition header field and the properties used for setting or updating.

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#import <CkoMime.h>

// The Content-Disposition header field provides a suggestion to the receiver for how the content is to be processed.
// The standard dispositions are "inline" and "attachment".  

// A disposition of "attachment" indicates the content is something to be saved to a file and not processed (such as rendering for viewing inline).
// A disposition of "inline" indicates the content should be processed (displayed) inline with the other parts of the MIME message.

// For example, an email client could handle a JPG image based on the disposition.  If the disposition is "attachment",
// the email client (such as Thunderbird, GMail, or Outlook) might simply list the JPG image as one of the email's attachments,
// but won't display the JPG image.  If the disposition is "inline", the email client might display the JPG image, but not list
// it as an attachment.

// The Content-Disposition header field can also include a "filename" attribute.  This is the suggested default filename if the content
// is to be saved to a file.

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

// The Content-Disposition header field can be set or modified in two ways.
// 1) By setting the Disposition and Filename properties.

// 2) By setting the entire contents of the Content-Disposition header with the SetHeaderField method.
//    Setting the Content-Disposition header automatically updates the Disposition and Filename properties.

// For example:
mime.Disposition = @"attachment";
mime.Filename = @"ghost.jpg";

// The Content-Disposition header field contains this:
//     Content-Disposition: attachment; filename="ghost.jpg"
NSLog(@"%@",[mime GetEntireHead]);
NSLog(@"%@",@"-");

// If we set the entire header field..
[mime SetHeaderField: @"Content-Disposition" value: @"attachment; filename=\"zombie.jpg\""];
// The Content-Disposition header field now contains this:
//     Content-Disposition: attachment; filename="zombie.jpg"
NSLog(@"%@",[mime GetEntireHead]);
NSLog(@"%@",@"-");

// Notice how the Filename property has been updated
NSLog(@"%@%@",@"Filename property: ",mime.Filename);
NSLog(@"%@",@"-");

// To change a particular attribute value, set the property.
mime.Filename = @"skeleton.jpg";
NSLog(@"%@",[mime GetEntireHead]);
NSLog(@"%@",@"-");

// To remove the filename from the Content-Disposition header,
// set the property to an empty string.
mime.Filename = @"";
NSLog(@"%@",[mime GetEntireHead]);
NSLog(@"%@",@"-");