(Node.js) The MIME Content-Type Header Field

Explains the ContentType property and the Content-Type header field including the various attributes that may be included.

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() {

    // Every part in a MIME messsage should include a Content-Type header field.
    // The Content-Type indicates the type of content contained in the MIME part.
    // For example: text/plain, image/jpeg, application/pdf, application/json, multipart/mixed, etc.

    // Multipart content types are those where the MIME part's body is composed of N inner MIME messages,
    // separated by a boundary string.
    // This is how MIME gets a nested, tree-like structure.  The most common multipart MIME types
    // are (for email related MIME) multipart/mixed, multipart/alternative, and multipart/related,
    // and for HTTP related MIME, it is multipart/form-data.

    var success;
    var mime = new chilkat.Mime();

    // The Content-Type header field can be set or modified in two ways.
    // 1) By setting the ContentType, Micalg, Name, Charset, Boundary, or Protocol properties.
    //    Setting the ContentType property sets the primary value (such as "text/plain") of the header field.
    //    Each of the other properties listed above will replace or add a particular attribute value.

    // 2) By setting the entire contents of the ContentType header with the SetHeaderField method.
    //    This updates each of the Content-Type related properties.

    // For example:
    mime.ContentType = "text/plain";
    mime.Charset = "utf-8";

    // The Content-Type header field contains this:
    //     Content-Type: text/plain; charset=utf-8
    console.log(mime.GetEntireHead());
    console.log("-");

    mime.SetHeaderField("Content-Type","image/jpeg; name=\"kitty.jpg\"");
    // The Content-Type header field now contains this:
    //     Content-Type: image/jpeg; name="kitty.jpg"
    console.log(mime.GetEntireHead());
    console.log("-");

    // Notice how the properties have been updated:
    console.log("ContentType property: " + mime.ContentType);
    console.log("Charset property: " + mime.Charset);
    console.log("Name property: " + mime.Name);
    console.log("-");

    // To change a particular attribute value, set the property.
    mime.Name = "doggy.jpg";
    console.log(mime.GetEntireHead());
    console.log("-");

    // To remove an attribute value from the Content-Type header,
    // set the property to an empty string.
    mime.Name = "";
    console.log(mime.GetEntireHead());
    console.log("-");

}

chilkatExample();