Add a Related Item from a BinData Object

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Demonstrates the Chilkat Email.AddRelatedBd method, which adds a related item (such as an inline image) using the contents of a BinData object, and returns the generated Content-ID. This example loads an image into a BinData, adds it, captures the Content-ID, and references it from the HTML body.

Background: This is the binary, Content-ID-based way to embed an inline resource — the right choice for images, whose bytes belong in a BinData rather than a string. Because Chilkat generates the Content-ID, the usual pattern is: add the item first, capture the returned ID, then build the matching <img src="cid:..."> reference from it (done here with a StringBuilder).

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    success := false

    //  Demonstrates the AddRelatedBd method, which adds a related item (such as an inline image)
    //  using the contents of a BinData object, and returns the generated Content-ID.

    email := chilkat.NewEmail()
    email.SetSubject("Related image from BinData")

    //  Load the image data from a file into a BinData object.
    bdImage := chilkat.NewBinData()
    success = bdImage.LoadFile("qa_data/images/logo.png")
    if success == false {
        fmt.Println(bdImage.LastErrorText())
        email.DisposeEmail()
        bdImage.DisposeBinData()
        return
    }

    //  Add the image as a related item; capture its generated Content-ID.
    cid := email.AddRelatedBd("logo.png",bdImage)
    if email.LastMethodSuccess() == false {
        fmt.Println(email.LastErrorText())
        email.DisposeEmail()
        bdImage.DisposeBinData()
        return
    }

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

    fmt.Println("NumRelatedItems = ", email.NumRelatedItems())

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

    email.DisposeEmail()
    bdImage.DisposeBinData()
    sbHtml.DisposeStringBuilder()