JavaScript

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.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

JavaScript

var success = false;

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

var email = new CkEmail();
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("qa_data/attachments/data.bin","application/octet-stream");
if (success == false) {
    console.log(email.LastErrorText);
    return true;
}

console.log("NumAttachments = " + email.NumAttachments);

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