(Go) Fetch 1st N Headers of Search Results

Calls Search to get a message set, then downloads the 1st N messages in the message set. There are two equivalent ways of doing it: (1) iterate from 0 to N-1 and download each message individually, or (2) create a new message set that contains the 1st N messages and pass it to FetchHeaders. Both are demonstrated here.

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    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    imap := chilkat.NewImap()

    // Connect to an IMAP server.
    // Use TLS
    imap.SetSsl(true)
    imap.SetPort(993)
    success := imap.Connect("imap.someMailServer.com")
    if success != true {
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        return
    }

    // Login
    success = imap.Login("****","****")
    if success != true {
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        return
    }

    // Select an IMAP mailbox
    success = imap.SelectMailbox("Inbox")
    if success != true {
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        return
    }

    // messageSet is a MessageSet
    // We can choose to fetch UIDs or sequence numbers.
    fetchUids := true
    // Get the message IDs of all the emails in the mailbox
    messageSet := imap.Search("ALL",fetchUids)
    if imap.LastMethodSuccess() == false {
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        return
    }

    numFound := messageSet.Count()
    if numFound == 0 {
        fmt.Println("No messages found.")
        messageSet.DisposeMessageSet()
        imap.DisposeImap()
        return
    }

    // Get the 1st 10 messages in messageSet.
    upperBound := 10
    if numFound < upperBound {
        upperBound = numFound
    }

    i := 0
    bUid := messageSet.HasUids()
    for i < upperBound {

        email := imap.FetchSingleHeader(*messageSet.GetId(i),bUid)
        if imap.LastMethodSuccess() == false {
            fmt.Println(imap.LastErrorText())
            messageSet.DisposeMessageSet()
            imap.DisposeImap()
            return

        }
        else {
            // Do whatever is needed with the email.. 
            // ....

            email.DisposeEmail()
        }

        i = i + 1
    }

    // Alternatively, create a new message set containing the 1st 10 message id's (UID's) 
    // from the search results message set:
    firstTen := chilkat.NewMessageSet()

    for i = 0; i <= upperBound - 1; i++ {
        firstTen.InsertId(*messageSet.GetId(i))
    }

    messageSet.DisposeMessageSet()

    // Download the 1st ten headers:
    // bundle is a EmailBundle
    bundle := imap.FetchHeaders(firstTen)
    if imap.LastMethodSuccess() == false {
        firstTen.DisposeMessageSet()
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        firstTen.DisposeMessageSet()
        return
    }

    // Other examples show how to iterate over the emails contained within the bundle...

    // Disconnect from the IMAP server.
    success = imap.Disconnect()

    firstTen.DisposeMessageSet()
    bundle.DisposeEmailBundle()

    imap.DisposeImap()
    firstTen.DisposeMessageSet()