Unicode 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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Unicode C

#include <C_CkEmailW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkEmailW email;

    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.

    email = CkEmailW_Create();
    CkEmailW_putSubject(email,L"Convert inline images");

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

    wprintf(L"NumRelatedItems before = %d\n",CkEmailW_getNumRelatedItems(email));

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

    success = CkEmailW_ConvertInlineImages(email);
    if (success == FALSE) {
        wprintf(L"%s\n",CkEmailW_lastErrorText(email));
        CkEmailW_Dispose(email);
        return true;
    }

    wprintf(L"NumRelatedItems after = %d\n",CkEmailW_getNumRelatedItems(email));


    CkEmailW_Dispose(email);

    }