JavaScript

Get the Content-Type of Each Alternative Body

Demonstrates the Chilkat Email.GetAlternativeContentType method, which returns the content type of the Nth alternative body. The NumAlternatives property gives the number of alternatives, and indexes are zero-based. This example builds a message with plain-text and HTML alternatives and prints the content type of each.

Background: Each alternative in a multipart/alternative message declares a Content-Type such as text/plain or text/html. Enumerating those types tells you which representations a message actually contains before you fetch a body — letting you decide, for instance, whether an HTML version exists or whether you must fall back to plain text. It is the natural companion to GetAlternativeBody, which fetches the body at the same index.

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

//  Demonstrates the GetAlternativeContentType method, which returns the content type of
//  the Nth alternative body.  The NumAlternatives property gives the number of
//  alternatives; indexes are zero-based.

var email = new CkEmail();

//  Create an email with plain-text and HTML alternatives.
email.SetTextBody("This is the plain-text alternative.","text/plain");
email.AddHtmlAlternativeBody("<html><body>This is the HTML alternative.</body></html>");

var n = email.NumAlternatives;
var i;
for (i = 0; i <= n - 1; i++) {
    console.log("Alternative " + i + " content type: " + email.GetAlternativeContentType(i));
}