Node.js
Add, Remove, Update MIME Header Fields

Demonstrates how to add, remove, or update the content of MIME header fields.
Chilkat Node.js Downloads

Node.js
NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    var mime = new chilkat.Mime();

    //  The contents of this MIME file are shown below, 
    //  and is also available at https://www.chilkatsoft.com/sampleMime.txt
    success = mime.LoadMimeFile("qa_data/mime/sampleMime.txt");
    if (success == false) {
        console.log(mime.LastErrorText);
        return;
    }

    //  The MIME used in this example has the following nested structure
    //  
    //  multipart/alternative
    //      text/plain
    //      multipart/related
    //          text/html
    //          image/jpeg
    //  

    //  Adding a top-level MIME header is easy.
    mime.AddHeaderField("hello-world","Hello World!");
    //  If a header field of the same name already exists, the AddHeaderField
    //  method adds a duplicate.
    mime.AddHeaderField("Subject","This is the 2nd Subject header.");
    console.log(mime.GetEntireHead());
    console.log("-");

    //  The top-level header now looks like this:
    //  
    //  	Subject: Test email.
    //  	Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
    //  	MIME-Version: 1.0
    //  	hello-world: Hello World!
    //  	Subject: This is the 2nd Subject header.
    //  

    //  The RemoveHeaderField method can remove the 1st occurrance, or all occurrences.
    var bAllOccurrences = true;
    //  Remove all occurrences of the Subject header;
    mime.RemoveHeaderField("Subject",bAllOccurrences);
    console.log(mime.GetEntireHead());
    console.log("-");

    //  After removing all Subject header fields, the top-level header now looks like this:
    //  
    //  Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
    //  MIME-Version: 1.0
    //  hello-world: Hello World!
    //  

    //  The content of a header field can be updated by calling SetHeaderField.
    //  If the header field does not already exist, it is added.  Otherwise it is updated.
    //  Note: The order of header fields SHOULD never matter.
    mime.SetHeaderField("hello-world","Goodbye World.");
    console.log(mime.GetEntireHead());
    console.log("-");

    //  Now we have:
    //  
    //  	Content-Type: multipart/alternative; boundary="------------DB171738719FB06D67DEBAA0"
    //  	MIME-Version: 1.0
    //  	hello-world: Goodbye World.
    //  

    //  To add/update/delete header fields in sub-parts, navigate to
    //  the sub-part and do the same..

    var mpRelated = new chilkat.Mime();
    mime.PartAt(1,mpRelated);

    var pJpg = new chilkat.Mime();
    mpRelated.PartAt(1,pJpg);

    //  Add a header to the image/jpeg sub-header.
    pJpg.SetHeaderField("CustomHeader","This is the custom header value.");

    //  View the entire MIME..
    console.log(mime.GetMime());

    //  --------------------------------------------------------------
    //  --------------------------------------------------------------
    //  The MIME sample file loaded at the beginning of this example
    //  contains the following MIME:

    //  Subject: Test email.
    //  Content-Type: multipart/alternative;
    //  	boundary="------------DB171738719FB06D67DEBAA0"
    //  MIME-Version: 1.0
    //  
    //  --------------DB171738719FB06D67DEBAA0
    //  Content-Type: text/plain; charset="utf-8"; format=flowed
    //  Content-Transfer-Encoding: 7bit
    //  
    //  This is a test.
    //  
    //  --------------DB171738719FB06D67DEBAA0
    //  Content-Type: multipart/related;
    //  	boundary="------------A940F1230E6F0105F03DB2CB"
    //  
    //  --------------A940F1230E6F0105F03DB2CB
    //  Content-Type: text/html; charset="utf-8"
    //  Content-Transfer-Encoding: 8bit
    //  
    //  <html><head>
    //  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    //    </head>
    //    <body bgcolor="#FFFFFF" text="#000000">
    //      <p>This is a test.&nbsp; <img src="cid:part1.E16AE3B4.1505C436@chilkatsoft.com" height="20" width="20"></p>
    //    </body>
    //  </html>
    //  
    //  --------------A940F1230E6F0105F03DB2CB
    //  Content-Type: image/jpeg; name="starfish20.jpg"
    //  Content-Transfer-Encoding: base64
    //  Content-ID: <part1.E16AE3B4.1505C436@chilkatsoft.com>
    //  Content-Disposition: inline; filename="starfish20.jpg"
    //  
    //  /9j/4AAQSkZJRgABAQEASABIAAD//gAmRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hvcD8g
    //  NC4w/9sAQwAQCwwODAoQDg0OEhEQExgoGhgWFhgxIyUdKDozPTw5Mzg3QEhcTkBEV0U3OFBtUVdf
    //  YmdoZz5NcXlwZHhcZWdj/9sAQwEREhIYFRgvGhovY0I4QmNjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj
    //  Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj/8IAEQgAFAAUAwERAAIRAQMRAf/EABcAAAMBAAAA
    //  AAAAAAAAAAAAAAIDBAX/xAAYAQADAQEAAAAAAAAAAAAAAAABAgMEAP/aAAwDAQACEAMQAAAB2kZY
    //  NNEijWKddfTmLgALWH//xAAbEAACAgMBAAAAAAAAAAAAAAABAgMRAAQSE//aAAgBAQABBQL0XqN+
    //  pM2aqJGMiqFFCyg7z//EABwRAAICAgMAAAAAAAAAAAAAAAERAAIQIQMSUf/aAAgBAwEBPwHqU5aq
    //  Axx+y1tMQl4elj//xAAcEQEAAQUBAQAAAAAAAAAAAAABEQACEBIhA1H/2gAIAQIBAT8B3Bhqy7Zc
    //  enyiwmGgDhiOzj//xAAdEAABAwUBAAAAAAAAAAAAAAABAAIREBIhIkFR/9oACAEBAAY/ArZyn+Cg
    //  xtxWuJaoCnqDuin/xAAcEAABBAMBAAAAAAAAAAAAAAABABEhYRAxQVH/2gAIAQEAAT8hkEwPUUR9
    //  DYfE4nxtRpIkBTsayuALIiuY/9oADAMBAAIAAwAAABDWPTsf/8QAGhEAAwADAQAAAAAAAAAAAAAA
    //  AAEREDFBIf/aAAgBAwEBPxC0DVPcWm+Ce4OesrkE6bjH/8QAGBEBAQEBAQAAAAAAAAAAAAAAAREA
    //  QRD/2gAIAQIBAT8QahMiOc8YgSrnTY3ELclHXn//xAAcEAEBAAIDAQEAAAAAAAAAAAABEQAhMUFx
    //  EFH/2gAIAQEAAT8Qn3igmSZSj+c4N4zapMy9IjFV98wncN2iuLFsCEbDGxQkI6RO/n//2Q==
    //  
    //  --------------A940F1230E6F0105F03DB2CB--
    //  
    //  --------------DB171738719FB06D67DEBAA0--
    //  

}

chilkatExample();