Is there a way to build a custom log file in JSL ?

[#1]

All, 
    I am building an application and would like to enable the users to be able to preview a log file that is custom built along with the script. I am of the opinion that this method, will help both me and the users in the future with troubleshooting. 

   I think, one way to write it is by building a list and writing the list out as a text file. But I am open to suggestions and wondering if there is a better, cleaner and more efficient way to do this. 

[#2 · Accepted solution]

I would just use the Save Text File function to append to a rolling log file. Se example below.

// some variables to show
x = 5;
y = 10;
z = 25;

// path to the log
logFilePath = "$TEMP/MyJmpAddin2.log";

// initialize the log in case it doesnt exist
If( !File Exists( logFilePath ), Save Text File( logFilePath, "" ) );

// function to write to the log file (with a new line character at the end)
writeToLog = Function( {str},
	Save Text File( 
		logFilePath, 
		Format( Today(), "m/d/y h:m:s" ) || " - " || str || "\!N",
		Mode( "append" )
	)
);

writeToLog( "showing x in JMP log" );
show( x );

writeToLog( "showing y in JMP log" );
show( y );

writeToLog( "showing z in JMP log" );
show( z );

// for demonstration purposes, open the log file as plain text
Open( logFilePath, "plain text" );

Here's the resulting log file:

01/31/2018 1:56:23 PM - showing x in JMP log
01/31/2018 1:56:23 PM - showing y in JMP log
01/31/2018 1:56:23 PM - showing z in JMP log

[#3]

I do something similar, here is my strategy for most projects:

1. All scripts have the same log format, this means it is easy to aggregate them.
2. For some add-ins logs are automatically uploaded to a central location. JMP 14 has a great method to aggregate all of these.
3. I use a csv format that also stores other info, like:
   1. Script/Add-In Name and Version
   2. OS/JMP version
   3. Function name
4. For add-ins, I load the 'writeToLog' function to a namespace for that add-in.  At the top of each script I define that namespace, so in any file within that add-in I can write log messages using ns:log("message", function="foo")