Wait for data with Indy10

Question

I have a TCP "Server", that is sending data every 20 seconds. I am trying to receive this data and display the result. Currently, the data is displayed 3 times instead of once. It then waits another 20 seconds, and again displays the data 3 times.

with Client do
begin

    Connect;

    while True do
    begin
        try
        if IOHandler.CheckForDataOnSource(1000) then
        begin
            WriteLn('Bytes available: ' IntToStr(IOHandler.InputBuffer.Size));
            IOHandler.ReadBytes(buffer, IOHandler.InputBuffer.Size);
        end;
        except
            on e : exception do
                writeln(e.message);
        end;

        if(buffer <> nil) then
        begin
            SetString(msg, PAnsiChar(@buffer[0], length(buffer));
            buffer := nil;
            IOHandler.InputBuffer.Clear;
        end;

        write(msg);
    end;
end;

Answer 1

I fixed the problem I was having, by moving the write(msg) into the if statement checking if the buffer is not nil.

with Client do
begin

    Connect;

    while True do
    begin
        try
            if IOHandler.CheckForDataOnSource(1000) then
            begin
                WriteLn('Bytes available: ' IntToStr(IOHandler.InputBuffer.Size));
                IOHandler.ReadBytes(buffer, IOHandler.InputBuffer.Size);
            end;
        except
            on e : exception do
                writeln(e.message);
        end;

        if(buffer <> nil) then
        begin
            SetString(msg, PAnsiChar(@buffer[0], length(buffer));
            buffer := nil;
            IOHandler.InputBuffer.Clear;
            write(msg); {only write out the message when the buffer is not nil}
        end;
    end;
end;