DataFlex

Add a Related File to an HTML Email

Demonstrates the Chilkat Email.AddRelatedFile method, which adds the contents of a local file as a related MIME resource and returns the generated Content-ID. The returned value is the bare Content-ID — no angle brackets and no cid: prefix — so if it returns CID-123@example, the HTML reference is cid:CID-123@example. Because the Content-ID is generated by the call, this example adds the image first, then builds the HTML body in a StringBuilder — using a placeholder in the <img> tag that is replaced with the returned Content-ID — and passes the result to SetHtmlBody.

Background: To embed an image so it displays inside an HTML email (rather than being downloaded from a web server), you add it as a "related" part and reference it from the HTML with a cid: URL that matches the part's Content-ID. Since Chilkat assigns that ID when you add the file, the natural order is: add the related file, capture the returned ID, then build the <img src="cid:..."> reference from it. A StringBuilder makes assembling and updating the HTML convenient.

Chilkat DataFlex Downloads

Download Chilkat for DataFlex

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoEmail
    String sCid
    Handle hoSbHtml
    Boolean iSuccess
    Integer iNumReplaced
    String sTemp1
    Integer iTemp1
    Boolean bTemp1

    //  Demonstrates the AddRelatedFile method, which adds a local file as a related MIME
    //  resource (such as an image displayed by an HTML body) and returns the generated
    //  Content-ID.  The HTML references the item using cid:<Content-ID>.

    Get Create (RefClass(cComChilkatEmail)) To hoEmail
    If (Not(IsComObjectCreated(hoEmail))) Begin
        Send CreateComObject of hoEmail
    End
    Set ComSubject Of hoEmail To "Email with a related image"

    //  Add the image file as a related item first.  The return value is the bare Content-ID
    //  (no angle brackets and no "cid:" prefix).
    Get ComAddRelatedFile Of hoEmail "qa_data/images/logo.png" To sCid
    Get ComLastMethodSuccess Of hoEmail To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoEmail To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Build the HTML body in a StringBuilder, using a placeholder where the image's
    //  Content-ID will go.
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbHtml
    If (Not(IsComObjectCreated(hoSbHtml))) Begin
        Send CreateComObject of hoSbHtml
    End
    Get ComAppend Of hoSbHtml '<html><body><img src="cid:PLACEHOLDER_CID"/></body></html>' To iSuccess

    //  Replace the placeholder with the actual Content-ID returned by AddRelatedFile.
    Get ComReplace Of hoSbHtml "PLACEHOLDER_CID" sCid To iNumReplaced

    //  Set the HTML body from the StringBuilder result.
    Get ComGetAsString Of hoSbHtml To sTemp1
    Send ComSetHtmlBody To hoEmail sTemp1

    Showln "Related Content-ID = " sCid
    Get ComNumRelatedItems Of hoEmail To iTemp1
    Showln "NumRelatedItems = " iTemp1

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


End_Procedure