DataFlex

Add an iCalendar Meeting Invitation to an Email

Demonstrates the Chilkat Email.AddiCalendarAlternativeBody method, which adds or replaces an iCalendar body as a text/calendar alternative. The first argument is the iCalendar content and the second is the iCalendar method (such as REQUEST, REPLY, or CANCEL). If an iCalendar alternative already exists it is replaced, so repeated calls leave at most one. This example attaches a simple meeting request.

Background: When you receive a calendar invite that your mail client shows with Accept/Decline buttons, it arrives as an iCalendar (.ics) body carried in the message as a text/calendar alternative. The METHOD — REQUEST to invite, CANCEL to withdraw, REPLY to respond — tells the recipient's client how to treat it. Delivering it as an alternative means clients that understand calendars show the invite UI, while others fall back to the plain-text or HTML body.

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Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoEmail
    String sIcal
    Boolean iSuccess
    Integer iTemp1

    //  Demonstrates the AddiCalendarAlternativeBody method, which adds (or replaces) an
    //  iCalendar body as a text/calendar alternative.  The first argument is the iCalendar content and the second
    //  is the iCalendar method (such as REQUEST, REPLY, or CANCEL).

    Get Create (RefClass(cComChilkatEmail)) To hoEmail
    If (Not(IsComObjectCreated(hoEmail))) Begin
        Send CreateComObject of hoEmail
    End
    Set ComSubject Of hoEmail To "Meeting invitation"
    Send ComSetTextBody To hoEmail "You are invited to the Project Sync meeting." "text/plain"

    //  The iCalendar (VCALENDAR) content.  In practice this is generated iCalendar text.
    Move "BEGIN:VCALENDAR" + (character(13)) + (character(10)) + "VERSION:2.0" + (character(13)) + (character(10)) + "METHOD:REQUEST" + (character(13)) + (character(10)) + "BEGIN:VEVENT" + (character(13)) + (character(10)) + "SUMMARY:Project Sync" + (character(13)) + (character(10)) + "DTSTART:20260720T160000Z" + (character(13)) + (character(10)) + "DTEND:20260720T163000Z" + (character(13)) + (character(10)) + "END:VEVENT" + (character(13)) + (character(10)) + "END:VCALENDAR" + (character(13)) + (character(10)) To sIcal

    //  Add the iCalendar as a text/calendar alternative using the REQUEST method.
    Get ComAddiCalendarAlternativeBody Of hoEmail sIcal "REQUEST" To iSuccess

    Get ComNumAlternatives Of hoEmail To iTemp1
    Showln "NumAlternatives = " iTemp1


End_Procedure