Node.js

Get the Content-ID of a Related Item

See more Email Object Examples

Demonstrates the Chilkat Email.GetRelatedContentID method, which returns the Content-ID of a related item (typically an image or style sheet embedded within an HTML email). The index is zero-based. This example loads an image from a file into a BinData object, adds it as a related item with AddRelatedBd (capturing the generated Content-ID and referencing it from the HTML), then reads that Content-ID back.

Background: The Content-ID is the anchor that ties an inline resource to the HTML that displays it: the body references cid: plus the ID, and the matching related part carries that same Content-ID. Because an image is binary, it is loaded into a BinData object (here from a file) and added with AddRelatedBd. Reading the Content-ID back lets a program verify or rewrite those links — for example when relocating embedded images or converting a message for display outside a mail client.

Chilkat Node.js Downloads

Download Chilkat for Node.js

Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

    //  Demonstrates the GetRelatedContentID method, which returns the Content-ID of a related
    //  item.  Related items are typically images and style sheets embedded within HTML emails.
    //  The index is zero-based.

    var email = new chilkat.Email();
    email.Subject = "GetRelatedContentID example";

    //  Load the image data from a file into a BinData object.
    var bdImage = new chilkat.BinData();
    success = bdImage.LoadFile("qa_data/images/logo.png");
    if (success == false) {
        console.log(bdImage.LastErrorText);
        return true;
    }

    //  Add the image as a related item from the BinData; capture its generated Content-ID.
    var cid = email.AddRelatedBd("logo.png",bdImage);
    if (email.LastMethodSuccess == false) {
        console.log(email.LastErrorText);
        return true;
    }

    //  Reference the related item in the HTML body by its Content-ID.
    var sbHtml = new chilkat.StringBuilder();
    sbHtml.Append("<html><body><img src=\"cid:PLACEHOLDER_CID\"/></body></html>");
    var numReplaced = sbHtml.Replace("PLACEHOLDER_CID",cid);
    email.SetHtmlBody(sbHtml.GetAsString());

    //  Read the Content-ID of the first related item (index 0).
    var cid0 = email.GetRelatedContentID(0);
    console.log("Related item 0 Content-ID: " + cid0);

    //  Note: The path "qa_data/images/logo.png" is a relative local filesystem path,
    //  relative to the current working directory of the running application.

}

chilkatExample();