Fidessa QUERY_MORE

SesssionExtensions_AutoQueryMore.cs

/// <summary>
///     Automatically requests more rows from a QUERY_IMAGE
/// </summary>
/// <param name="session">Fidessa session</param>
/// <param name="queryName">Query name</param>
/// <param name="userName">User name</param>
/// <param name="count">
///     <para>when specified, continue to request rows while the # of rows returns are less than count</para>
///     <para>when null, QUERY_MORE will be sent when MORE = 1</para>
/// </param>
public static void AutoQueryMore(this Session session, string queryName, string userName, long? count)
{
    long responseCount = 0;

    void OnReceivedData(object sender, SessionDataEventArgs e)
    {
        var data = e?.Data;
        if (null == data || !data.ContainsKey("MESSAGE_TYPE") || data.String("MESSAGE_TYPE") != "QUERY_IMAGE")
            return;

        if (data.ContainsKey("ROW"))
            responseCount += data.SdsList("ROW").Count;

        if (!data.ContainsKey("MORE"))
            return;

        var more = data.I32("MORE") ?? -1;
        switch (more)
        {
            case 0:
                // IMAGE has completed - unsubscribe
                session.ReceivedData -= OnReceivedData;
                break;
            case 1:
                if (count.HasValue && responseCount >= count.Value)
                    break;

                // ask for more
                session.Send(
                    new Sds
                    {
                        {"MESSAGE_TYPE", "QUERY_MORE"},
                        {"QUERY_NAME", queryName},
                        {"USER_NAME", userName}
                    });
                break;
        }
    }

    session.ReceivedData += OnReceivedData;
}