(Node.js) Iterate MIME Parts of an Email

Demonstrates how to iterate over the MIME sub-parts of an email, and retrieve the content of each MIME sub-part body.

Note: This example requires some new features added to Chilkat v9.5.0.95.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    // See the following Chilkat post to Quickly Understand Email MIME

    var email = new chilkat.Email();

    var success = email.LoadEml("qa_data/eml/sample.eml");
    if (success == false) {
        console.log("Failed to load .eml");
        return;
    }

    var sbContentType = new chilkat.StringBuilder();
    var caseSensitive = false;

    // Get the total number of non-multipart MIME sub-parts.
    // (This is a simple way of iterating over all the MIME leaf parts regardless of the MIME tree structure)
    var inlineOnly = false;
    var excludeAttachments = false;
    var searchSpec = "*/*";

    var numParts = email.GetNumPartsOfType(searchSpec,inlineOnly,excludeAttachments);
    var i = 0;
    while (i < numParts) {
        // What is the Content-Type of this MIME part?
        sbContentType.Append(email.GetNthContentType(i,searchSpec,inlineOnly,excludeAttachments));
        if (sbContentType.StartsWith("text/",caseSensitive) == true) {
            // Get the text body of this MIME part.
            var textBody = email.GetNthTextPartOfType(i,searchSpec,inlineOnly,excludeAttachments);
            console.log("Got text body for " + sbContentType.GetAsString());
        }
        else {
            if (sbContentType.ContentsEqual("message/rfc822",caseSensitive) == true) {
                // If the Content-Type is message/rfc822, then the MIME body for this part contains a full embedded MIME messages.
                // Your application could load it into a Chilkat email object and recursively process...
                var attachedEmail = new chilkat.Email();
                var bdMime = new chilkat.BinData();
                email.GetNthBinaryPartOfTypeBd(i,searchSpec,inlineOnly,excludeAttachments,bdMime);
                attachedEmail.SetFromMimeBd(bdMime);
                // Now your app can recursively process the attachedEmail...
            }
            else {
                // Get the bytes of this MIME body part.
                var bd = new chilkat.BinData();
                email.GetNthBinaryPartOfTypeBd(i,searchSpec,inlineOnly,excludeAttachments,bd);
                console.log("Got binary body for " + sbContentType.GetAsString() + " numBytes = " + bd.NumBytes);
            }

        }

        sbContentType.Clear();
        i = i+1;
    }


}

chilkatExample();