Swift

Attach a File with an Explicit Content Type

Demonstrates the Chilkat Email.AddFileAttachment2 method, which attaches a file from the filesystem and lets you explicitly specify its content type rather than having Chilkat infer it from the file extension. This example attaches a binary file as application/octet-stream.

Background: Extension-based type detection is convenient but not always right — a file may have an unusual or missing extension, or you may need a very specific MIME type for the recipient to process it correctly. Specifying the content type explicitly removes the guesswork. application/octet-stream is the generic "arbitrary binary data" type, a safe default that tells the client to treat the attachment as an opaque download rather than trying to render it.

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Swift


func chilkatTest() {
    var success: Bool = false

    //  Demonstrates the AddFileAttachment2 method, which attaches a file and lets you
    //  explicitly specify its content type instead of letting Chilkat infer it.

    let email = CkoEmail()!
    email.subject = "Email with a file attachment"
    email.body = "Please see the attached file."

    //  Attach a file, explicitly specifying the content type.
    success = email.addFileAttachment2(path: "qa_data/attachments/data.bin", contentType: "application/octet-stream")
    if success == false {
        print("\(email.lastErrorText!)")
        return
    }

    print("NumAttachments = \(email.numAttachments.intValue)")

    //  Note: The path "qa_data/attachments/data.bin" is a relative local filesystem path,
    //  relative to the current working directory of the running application.

}