Ruby
Send HTML Email with External CSS as Related Item

Demonstrates how to compose an HTML email with an external CSS file included as a related item and referenced by CID (Content-ID).
Chilkat Ruby Downloads

Download Chilkat for Ruby
Ruby
require 'chilkat'

success = false

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

# The mailman object is used for sending and receiving email.
mailman = Chilkat::CkMailMan.new()

# Use your SMTP server hostname.  This example uses office365, but it could be any SMTP server..
mailman.put_SmtpHost("outlook.office365.com")
mailman.put_SmtpPort(587)
mailman.put_StartTLS(true)

# Set the SMTP login/password
mailman.put_SmtpUsername("OFFICE365-SMTP-LOGIN")
mailman.put_SmtpPassword("OFFICE365-SMTP-PASSWORD")

# Create a new email object
email = Chilkat::CkEmail.new()
email.put_Subject("HTML Email with embedded CSS")
email.put_From("Chilkat Support <my-office365-user@mydomain.com>")
email.AddTo("Chilkat Support","support@chilkatsoft.com")

sbCss = Chilkat::CkStringBuilder.new()
bCrlf = true
sbCss.AppendLine("body {",bCrlf)
sbCss.AppendLine("    background-color: powderblue;",bCrlf)
sbCss.AppendLine("}",bCrlf)
sbCss.AppendLine("h1 {",bCrlf)
sbCss.AppendLine("    color: blue;",bCrlf)
sbCss.AppendLine("}",bCrlf)
sbCss.AppendLine("p {",bCrlf)
sbCss.AppendLine("    color: red;",bCrlf)
sbCss.AppendLine("}",bCrlf)

# It's possible to add a CSS file directly by calling AddRelatedFile.
# This example will add the CSS from a string.
filenameInHtml = "styles.css"
contentIdCss = email.addRelatedString(filenameInHtml,sbCss.getAsString(),"utf-8")
if (email.get_LastMethodSuccess() != true)
    print email.lastErrorText() + "\n";
    exit
end

# The src attribute for the image tag is set to the contentIdCss:
sbHtml = Chilkat::CkStringBuilder.new()
sbHtml.AppendLine("<!DOCTYPE html>",bCrlf)
sbHtml.AppendLine("<html>",bCrlf)
sbHtml.AppendLine("<head>",bCrlf)
sbHtml.AppendLine("  <link rel=\"stylesheet\" href=\"cid:CONTENT_ID_CSS\">",bCrlf)
sbHtml.AppendLine("</head>",bCrlf)
sbHtml.AppendLine("<body>",bCrlf)
sbHtml.AppendLine("",bCrlf)
sbHtml.AppendLine("<h1>This is a heading</h1>",bCrlf)
sbHtml.AppendLine("<p>This is a paragraph.</p>",bCrlf)
sbHtml.AppendLine("",bCrlf)
sbHtml.AppendLine("</body>",bCrlf)
sbHtml.AppendLine("</html>",bCrlf)

numReplacements = sbHtml.Replace("CONTENT_ID_CSS",contentIdCss)

email.SetHtmlBody(sbHtml.getAsString())

success = mailman.SendEmail(email)
if (success != true)
    print mailman.lastErrorText() + "\n";
else
    print "Mail Sent!" + "\n";
end