Help editing the imageTracing.jsx Script

Question

Hello, I am looking for guidance on how to properly edit the imageTracing.jsx script in Illustrator CC. At the moment it only defaults to using a basic black and white trace, I need the trace to use one of my presets, expand the trace and save it. I need to run thousands of frames of bitmap animation through a batch trace process essentially. I've tried to batch it through Bridge, but it just throws up and error (59 I believe) and I've set up an action to try and batch that way but it never completes the batch by expanding the trace.
I've tried editing the script myself, but if I change the preset numeral it appears to break the save and close functionality of the script. Not quite sure what I am doing wrong. I've also tried adding a line for expanding the trace but I may be using the wrong syntax  --- tracing.expandTracing(); ---
Below is the default script as shipped with Illustrator, no changes made.
// Main Code [Execution of script begins here]
// uncomment to suppress Illustrator warning dialogs
// app.userInteractionLevel = UserInteractionLevel.DONTDISPLAYALERTS;
// Collectable files
var COLLECTABLE_EXTENSIONS = ["bmp", "gif", "giff", "jpeg", "jpg", "pct", "pic", "psd", "png", "tif", "tiff"];
var destFolder, sourceFolder;
// Select the source folder
sourceFolder = Folder.selectDialog( 'Select the SOURCE folder...', '~' );
//sourceFolder = new Folder("C:/Users/<Username>/Desktop/1");
if(sourceFolder != null)
    // Select the destination folder
    destFolder = Folder.selectDialog( 'Select the DESTINATION folder...', '~' );       
    //destFolder = new Folder("C:/Users/<Username>/Desktop/2");
if(sourceFolder != null && destFolder != null)
        //getting the list of the files from the input folder
        var fileList = sourceFolder.getFiles();
        var errorList;
        var tracingPresets = app.tracingPresetsList;
        for (var i=0; i<fileList.length; ++i)
            if (fileList[i] instanceof File)
                 try
                        var fileExt = String(fileList[i]).split (".").pop();
                        if(isTraceable(fileExt) != true)
                            continue;
                        // Trace the files by placing them in the document.
                        // Add a document in the app
                        var doc = app.documents.add();
                        // Add a placed item
                        var p = doc.placedItems.add();
                        p.file = new File(fileList[i]);
                        // Trace the placed item
                        var t = p.trace();
                        t.tracing.tracingOptions.loadFromPreset(tracingPresets[3]);
                        app.redraw();
                        var destFileName = fileList[i].name.substring(0, fileList[i].name.length - fileExt.length-1) + "_" +fileExt;
                        var outfile = new File(destFolder+"/"+destFileName);
                        doc.saveAs(outfile);
                        doc.close();
                catch (err)
                        errorStr = ("Error while tracing "+ fileList[i].name  +".\n" + (err.number & 0xFFFF) + ", " + err.description);
                        // alert(errorStr);
                        errorList += fileList[i].name + " ";
       fileList = null;
       alert("Batch process complete.");
else
       alert("Batch process aborted.");
sourceFolder = null;
destFolder = null;
function isTraceable(ext)
     var result = false;
     for (var i=0; i<COLLECTABLE_EXTENSIONS.length; ++i)
          if(ext == COLLECTABLE_EXTENSIONS[i])
            result = true;
            break;
    return result;
And this is the amended version with my change to lines 57 and 58.
// Main Code [Execution of script begins here]
// uncomment to suppress Illustrator warning dialogs
// app.userInteractionLevel = UserInteractionLevel.DONTDISPLAYALERTS;
// Collectable files
var COLLECTABLE_EXTENSIONS = ["bmp", "gif", "giff", "jpeg", "jpg", "pct", "pic", "psd", "png", "tif", "tiff"];
var destFolder, sourceFolder;
// Select the source folder
sourceFolder = Folder.selectDialog( 'Select the SOURCE folder...', '~' );
//sourceFolder = new Folder("C:/Users/<Username>/Desktop/1");
if(sourceFolder != null)
    // Select the destination folder
    destFolder = Folder.selectDialog( 'Select the DESTINATION folder...', '~' );       
    //destFolder = new Folder("C:/Users/<Username>/Desktop/2");
if(sourceFolder != null && destFolder != null)
        //getting the list of the files from the input folder
        var fileList = sourceFolder.getFiles();
        var errorList;
        var tracingPresets = app.tracingPresetsList;
        for (var i=0; i<fileList.length; ++i)
            if (fileList[i] instanceof File)
                 try
                        var fileExt = String(fileList[i]).split (".").pop();
                        if(isTraceable(fileExt) != true)
                            continue;
                        // Trace the files by placing them in the document.
                        // Add a document in the app
                        var doc = app.documents.add();
                        // Add a placed item
                        var p = doc.placedItems.add();
                        p.file = new File(fileList[i]);
                        // Trace the placed item
                        var t = p.trace();
                        t.tracing.tracingOptions.loadFromPreset(tracingPresets[1]);
  tracing.expandTracing();
  app.redraw();
                        var destFileName = fileList[i].name.substring(0, fileList[i].name.length - fileExt.length-1) + "_" +fileExt;
                        var outfile = new File(destFolder+"/"+destFileName);
                        doc.saveAs(outfile);
                        doc.close();
                catch (err)
                        errorStr = ("Error while tracing "+ fileList[i].name  +".\n" + (err.number & 0xFFFF) + ", " + err.description);
                        // alert(errorStr);
                        errorList += fileList[i].name + " ";
       fileList = null;
       alert("Batch process complete.");
else
       alert("Batch process aborted.");
sourceFolder = null;
destFolder = null;
function isTraceable(ext)
     var result = false;
     for (var i=0; i<COLLECTABLE_EXTENSIONS.length; ++i)
          if(ext == COLLECTABLE_EXTENSIONS[i])
            result = true;
            break;
    return result;
Thanks in advance for your help, as you can imagine, manually tracing thousands of images for a client job will be a nightmare if I can't sort out a batch.

Answer 1

hello,
after line 32 :
var tracingPresets = app.tracingPresetsList;
do an alert :
alert( app.tracingPresetsList );
it'll show you the name of the differents presets
then line 57, call the good preset :
t.tracing.tracingOptions.loadFromPreset('here the name of your preset');
for expanding :
change line 58 like that :
t.tracing.expandTracing();
you forget (t.) at the beginning
best wishes for the new year