DataFlex

Fetch a Range of IMAP Messages by Sequence Number

Demonstrates the Chilkat Imap.FetchRange method, which downloads a contiguous run of messages by sequence number. The arguments are headersOnly, the starting sequence number, the count of messages, and the EmailBundle that receives them. This example uses the message count returned by SelectMailbox to fetch the headers of the 10 most recent messages.

Background: IMAP sequence numbers are 1-based positions within the selected mailbox, from 1 (oldest) to the message count (newest), and they shift whenever messages are expunged. That makes FetchRange ideal for "give me the newest N" style paging within a single session, but note that sequence numbers are not stable identifiers across sessions the way UIDs are — use a UID-based approach if you need to remember which messages you have already seen.

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DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoImap
    Integer iNumMessages
    Integer iStartSeqnum
    Variant vBundle
    Handle hoBundle
    Integer n
    String sTemp1

    Move False To iSuccess

    //  Demonstrates the Imap.FetchRange method, which downloads a contiguous run of messages by
    //  sequence number.  The 1st argument is headersOnly, the 2nd is the starting sequence number,
    //  the 3rd is the count of messages, and the 4th is the EmailBundle that receives them.

    Get Create (RefClass(cComChilkatImap)) To hoImap
    If (Not(IsComObjectCreated(hoImap))) Begin
        Send CreateComObject of hoImap
    End

    Set ComSsl Of hoImap To True
    Set ComPort Of hoImap To 993

    Get ComConnect Of hoImap "imap.example.com" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComLogin Of hoImap "user@example.com" "myPassword" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  SelectMailbox returns the number of messages in the mailbox, or -1 on failure.
    Get ComSelectMailbox Of hoImap "Inbox" To iNumMessages
    If (iNumMessages < 0) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Download the 10 most recent messages (headers only).
    Move (iNumMessages - 9) To iStartSeqnum
    If (iStartSeqnum < 1) Begin
        Move 1 To iStartSeqnum
    End

    Get Create (RefClass(cComChilkatEmailBundle)) To hoBundle
    If (Not(IsComObjectCreated(hoBundle))) Begin
        Send CreateComObject of hoBundle
    End
    Get pvComObject of hoBundle to vBundle
    Get ComFetchRange Of hoImap True iStartSeqnum 10 vBundle To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComMessageCount Of hoBundle To n
    Showln "Fetched " n " message headers."

    Get ComDisconnect Of hoImap To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoImap To sTemp1
        Showln sTemp1
        Procedure_Return
    End



End_Procedure