Can't Apply StreamWriter to two Charts

[Taddypole]

When I apply an indicator with StreamWriter to one chart it works, but when I try to apply that same indicator to a second chart, it does not load on the second chart but continues to work on the first chart. I get no error messages and nothing in the Log.

Is it possible for StreamWriter to write to the same file from two different charts?

regards,
taddypole....


================================================== ===========

Variables

private System.IO.StreamWriter sw;

OnStartUp()

sw = new StreamWriter(@"c:\temp\recordedTrades.txt", false);

[sledge]

When I apply an indicator with StreamWriter to one chart it works, but when I try to apply that same indicator to a second chart, it does not load on the second chart but continues to work on the first chart. I get no error messages and nothing in the Log.

Is it possible for StreamWriter to write to the same file from two different charts?

regards,
taddypole....


================================================== ===========

Variables

private System.IO.StreamWriter sw;

OnStartUp()

sw = new StreamWriter(@"c:\temp\recordedTrades.txt", false);

And if you were to use a different file name for the other chart it work?

Also adding a try/catch with Print would return any errors to NT output window.

[Taddypole]

Thanks Sledge,

Yes, using a different file name does work, but I was hoping to be able to have either chart write to the same file. Is that possible?

taddypole....

[koganam]

When I apply an indicator with StreamWriter to one chart it works, but when I try to apply that same indicator to a second chart, it does not load on the second chart but continues to work on the first chart. I get no error messages and nothing in the Log.

Is it possible for StreamWriter to write to the same file from two different charts?

regards,
taddypole....


================================================== ===========

Variables

private System.IO.StreamWriter sw;

OnStartUp()

sw = new StreamWriter(@"c:\temp\recordedTrades.txt", false);

You need to open the file correctly for concurrent access.

ref: http://msdn.microsoft.com/en-us/libr...(v=VS.90).aspx

[NinjaTrader_PatrickH]

Hello Taddypole,

Thank you for your post.

Koganam provides the needed enumeration here to allow multiple scripts to access and write to the same file. If you have any questions on implementing this into your scripts please let me know.

[forrestang]

Hello Taddypole,

Thank you for your post.

Koganam provides the needed enumeration here to allow multiple scripts to access and write to the same file. If you have any questions on implementing this into your scripts please let me know.

Can you post the lines on how this script would need to be modified?

http://www.ninjatrader.com/support/forum/showthread.php?t=3475

        #region Variables
		// This sets the path in which the text file will be created.
		private string path 			= "C:\\Users\\Forrest\\Desktop\\MyTestFile.txt";
		private System.IO.StreamWriter sw;
        #endregion

        protected override void Initialize()
        {
            CalculateOnBarClose	= true;
        }

        protected override void OnBarUpdate()
        {
			try
			{
				if (CurrentBar == 0)
					sw = File.AppendText(path);

				sw.WriteLine(ToDay(Time[0]) + " " + Open[0] + " " + High[0] + " " + Low[0] + " " + Close[0]);
			}
			
			catch (Exception e)
			{
				Log("You cannot write and read from the same file at the same time. Please remove SampleStreamReader.", NinjaTrader.Cbi.LogLevel.Error);
				throw;
			}
		}
        }

		protected override void OnTermination() 
		{
			if (sw != null)
			{
				sw.Dispose();
				sw = null;
			}
		}

[NinjaTrader_PatrickH]

Hello forrestang,

Thank you for your post.

You would need to add the FileStream() to the following lines of code in the OnBarUpdate() Try Catch:

				if (CurrentBar == 0)
				{
					fs = new FileStream(path, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
					sw = File.AppendText(path);

fs would need to be defined as a FileStream in the variables section of the code:

        #region Variables
		...
		// Creates a StreamWriter and a StreamReader object
		private System.IO.StreamWriter sw;
		private FileStream fs;
        #endregion

[Taddypole]

Hello Taddypole,

Thank you for your post.

Koganam provides the needed enumeration here to allow multiple scripts to access and write to the same file. If you have any questions on implementing this into your scripts please let me know.

I've pulled out all the relevant references to the filestream, streamwriters and streamreaders from the indicator that I'm having problems using on more than one chart. They are listed in the StreamWriter Conflict Code.txt attached.

I've tried to address the fileShare enumeration issue that Koganam referred to but no luck. Also, I've attached a print of the output screen of the errors that I get when I try to load the indicator onto a second chart. Those are found in the output.txt attachment.

Just not sure what I'm doing wrong.

Regards,
taddypole...

[NinjaTrader_Bertrand]

taddypole, naturally this being a deeper C# topic there's limited support we could provide here, however running some quick testing with NG and ES 1 min charts the attached seems to work well for me write from two charts to the same file. Append mode needs to be done in Write mode, but feel for your logging that would be sufficient.

[Taddypole]

thank you Bertrand

I verified the your code can write to the same file from two different charts. So that's affirmed.

I then modified the code to read the Ninja Trader Log file. When I do that, I get an error. I've attached a screen shot in VS showing that the error is realted to the log file being in use.

In the FileStream used for logPath, I've enumerated the FileShare to be "Read". Shouldn't that allow me to read the Ninja Trader log file even though it is in use by Ninja Trader?

[koganam]

thank you Bertrand

I verified the your code can write to the same file from two different charts. So that's affirmed.

I then modified the code to read the Ninja Trader Log file. When I do that, I get an error. I've attached a screen shot in VS showing that the error is realted to the log file being in use.

In the FileStream used for logPath, I've enumerated the FileShare to be "Read". Shouldn't that allow me to read the Ninja Trader log file even though it is in use by Ninja Trader?

No. Not if the previous application that opened the file opened it for exclusive access. That is the same reason that you have to make specific access available when you arrange to open your own file, the reason for this thread in the first place.

Just think about it: if we could overrride restricted access by simply opening a filestream in a more permissive mode to access the same restricted file, then no file restrictions can ever be valid.

[Taddypole]

Thanks Koganam

But what I knew is that I can read the file using NotePad... so I thought I should be able to also read it using FileStream. I did more searching on the web and found that someone suggested that FileShare needed to be ReadWrite and not just Read. This doesn't make sense to me but when I tried it, I no longer got the error.

I assume what this means is if Ninja has a ReadWrite FileShare on the log file, then I need to match it with my FileStream.

Just a guess....
regards,
taddypole...

[koganam]

Thanks Koganam

But what I knew is that I can read the file using NotePad... so I thought I should be able to also read it using FileStream. I did more searching on the web and found that someone suggested that FileShare needed to be ReadWrite and not just Read. This doesn't make sense to me but when I tried it, I no longer got the error.

I assume what this means is if Ninja has a ReadWrite FileShare on the log file, then I need to match it with my FileStream.

Just a guess....
regards,
taddypole...

That does surprise me. Logic would seem to imply that a file should be accessible if opened a second time in a more restrictive mode by a new filestream. Apparently not, it seems. The notion that all filestreams accessing the file must use the same mode is one that I did not realize, maybe because the only time I have ever used such multiple access has been with files that I created, so I always used the same mode for all access, even as I did not realize that it was actually required.

What you observed relative to Notepad would make sense too, as Notepad definitely opens files in ReadWrite mode.