C++

Convert Inline Data-URL Images to Related Parts

Demonstrates the Chilkat Email.ConvertInlineImages method, which converts images embedded inline within HTML (as base64 data URLs) into multipart/related MIME parts referenced from the HTML by cid:. This example sets an HTML body containing a data-URL image and converts it.

Background: HTML can embed an image two ways: as a data: URL (the base64 bytes sit right in the src attribute) or as a related part referenced by cid:. Many email clients don't render data: URLs for security reasons, so converting them to proper multipart/related parts — the traditional email way to embed images — greatly improves how reliably the images display.

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C++

#include <CkEmail.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the ConvertInlineImages method, which converts images embedded inline within
    //  HTML (as base64 data URLs) into multipart/related MIME parts referenced from the HTML by
    //  CID.

    CkEmail email;
    email.put_Subject("Convert inline images");

    //  An HTML body with a base64 data-URL image (a 1x1 PNG).
    email.SetHtmlBody("<html><body><img src=\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg==\"/></body></html>");

    std::cout << "NumRelatedItems before = " << email.get_NumRelatedItems() << "\r\n";

    //  Convert the inline data-URL image(s) to multipart/related parts referenced by CID.

    success = email.ConvertInlineImages();
    if (success == false) {
        std::cout << email.lastErrorText() << "\r\n";
        return true;
    }

    std::cout << "NumRelatedItems after = " << email.get_NumRelatedItems() << "\r\n";
    }