C++

Get a Header Attribute of an Attached Message

Demonstrates the Chilkat Email.GetAttachedMessageAttr method, which returns a header-field attribute value for the Nth attached (embedded) email. The first argument is the zero-based attached-message index, the second is the header field name, and the third is the attribute name. This example attaches an email and reads the filename attribute of its Content-Disposition header.

Background: MIME header fields can carry named attributes (parameters) after the main value — for example Content-Disposition: attachment; filename="report.eml", where filename is an attribute. Rather than parsing the raw header yourself, this method extracts a single named attribute from a chosen header of a specific embedded message, which is convenient when a message forwards other emails as nested message/rfc822 parts.

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C++

#include <CkEmail.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the GetAttachedMessageAttr method, which returns a header-field attribute
    //  value for the Nth attached (embedded) email.  The first argument is the zero-based
    //  attached-message index, the second is the header field name, and the third is the attribute name.

    //  Build an inner email to attach.
    CkEmail innerEmail;
    innerEmail.put_Subject("Embedded message");
    innerEmail.put_From("alice@example.com");
    innerEmail.AddTo("Bob","bob@example.com");

    //  Attach it to an outer email as a message/rfc822 part.
    CkEmail email;
    email.put_Subject("Has an attached message");
    success = email.AttachEmail(innerEmail);
    if (success == false) {
        std::cout << email.lastErrorText() << "\r\n";
        return true;
    }

    //  Get the "filename" attribute of the "Content-Disposition" header of the first
    //  attached message (index 0).
    const char *fname = email.getAttachedMessageAttr(0,"Content-Disposition","filename");
    std::cout << "Attached message filename attribute: " << fname << "\r\n";
    }