Classic ASP

Add a Custom Header to a Related Item

Demonstrates the Chilkat Email.AddRelatedHeader method, which adds a custom MIME header field to an existing related item identified by its zero-based index. This example first adds a related style sheet (which becomes index 0) and captures its generated Content-ID, builds an HTML body that references the style sheet by that cid:, then attaches an extra header field to the related item and prints the resulting MIME.

Background: Like attachments, each related item (an inline image, style sheet, etc.) is a MIME part with its own small header block describing that part — Content-Type, Content-ID, Content-Location, and so on. AddRelatedHeader lets you insert additional fields into that per-part block, which is occasionally required for interoperability with clients that look for specific custom headers on embedded resources.

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Classic ASP

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
'  Demonstrates the AddRelatedHeader method, which adds a custom MIME header field to an
'  existing related item, identified by its zero-based index.

set email = Server.CreateObject("Chilkat.Email")
email.Subject = "Related item with a custom header"

'  Add a related item first (a style sheet); capture its generated Content-ID.  It becomes
'  related-item index 0.
cid = email.AddRelatedString("styles.css","body { color: black; }","utf-8")
If (email.LastMethodSuccess = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( email.LastErrorText) & "</pre>"
    Response.End
End If

'  Build the HTML body, referencing the related style sheet by its Content-ID.  A
'  placeholder is used and then replaced with the actual Content-ID.
set sbHtml = Server.CreateObject("Chilkat.StringBuilder")
success = sbHtml.Append("<html><head><link rel=""stylesheet"" href=""cid:PLACEHOLDER_CID""/></head><body>Styled content.</body></html>")
numReplaced = sbHtml.Replace("PLACEHOLDER_CID",cid)
email.SetHtmlBody sbHtml.GetAsString()

'  Add a custom header field to the first related item (index 0).
email.AddRelatedHeader 0,"X-Custom-Related-Header","some value"

'  The custom header now appears in the related item's MIME part.
Response.Write "<pre>" & Server.HTMLEncode( email.GetMime()) & "</pre>"

%>
</body>
</html>