Need help in automating batch placing of images on spreads

Question

My workflow is :
I have jpeg files (mostly 100+).
They are the size of 2 pages (e.g. 1 spread per jpeg file)
I need to place them on either even or odd page (aligned Top-Left).
Currently I’m doing this work manually.
Need help to automate this.
Thanks and regards.

Answer 1

As I mentioned earlier I have very little experience with JavaScript.
I also copied the ImageCatalog script to a new file and read it atleast five times, and tried to wrap my head around the flow of execution.
The comments were really helpful in the process.
I proritized what i want to achive with my script and started deleting unwanted code. I also tested it frequently.
Here is my script as it stands right now.
function Init(){
        var myFilteredFiles;
        //Make certain that user interaction (display of dialogs, etc.) is turned on.
        app.scriptPreferences.userInteractionLevel = UserInteractionLevels.interactWithAll;
        myExtensions = [".jpg", ".jpeg"]
        //Display the folder browser.
        var myFolder = Folder.selectDialog("Select the folder containing the images", "");
        //Get the path to the folder containing the files you want to place.
        if(myFolder != null){
                    if(File.fs == "Macintosh"){
                        myFilteredFiles = myMacOSFileFilter(myFolder);
                    else{
                        myFilteredFiles = myWinOSFileFilter(myFolder);
                    if(myFilteredFiles.length != 0){
                            myPlaceImages(myFilteredFiles);
                            alert("Done!");
// call the initial function
Init();
//Windows version of the file filter.
function myWinOSFileFilter(myFolder){
          var myFiles = new Array;
          var myFilteredFiles = new Array;
          for(myExtensionCounter = 0; myExtensionCounter < myExtensions.length; myExtensionCounter++){
                    myExtension = myExtensions[myExtensionCounter];
        myFiles = myFolder.getFiles("*"+ myExtension);
                    if(myFiles.length != 0){
                              for(var myFileCounter = 0; myFileCounter < myFiles.length; myFileCounter++){
                                        myFilteredFiles.push(myFiles[myFileCounter]);
          return myFilteredFiles;
function myMacOSFileFilter(myFolder){
          var myFilteredFiles = myFolder.getFiles(myFileFilter);
          return myFilteredFiles;
//Mac OS version of file filter
//Have to provide a separate version because not all Mac OS users use file extensions
//and/or file extensions are sometimes hidden by the Finder.
function myFileFilter(myFile){
          var myFileType = myFile.type;
          switch (myFileType){
                    case "JPEG":
        return true;
                              break;
                    default:
                    for(var myCounter = 0; myCounter<myExtensions.length; myCounter++){
                              var myExtension = myExtensions[myCounter];
                              if(myFile.name.indexOf(myExtension)>-1){
                                        return true;
                                        break;
          return false;
function myPlaceImages(myFiles){
        var myDocument = app.documents.item(0);
        var myDocumentPreferences = myDocument.documentPreferences;        
        var myNumberOfFiles = myFiles.length;
        alert(myNumberOfFiles);
        var myNumberOfPages = (myNumberOfFiles * 2) + 1;
        myDocumentPreferences.pagesPerDocument = myNumberOfPages;       
        var myPage = myDocument.pages.item(0);
        var myPages = myDocument.pages;
        for (myCounter = myDocument.pages.length-1; myCounter >= 0; myCounter--){ 
            if(myCounter%2 == 1){
                 myPage = myPages.item(myCounter);
                var myLiveWidth = myDocumentPreferences.pageWidth
                var myLiveHeight = myDocumentPreferences.pageHeight
                myY1 = 0
                myY2 = myLiveHeight
                myX1 = 0
                myX2 = myLiveWidth * 2
                myRectangle = myPage.rectangles.add(myDocument.layers.item(-1), undefined, undefined, {geometricBounds:[myY1, myX1, myY2, myX2], strokeWeight:0, strokeColor:myDocument.swatches.item("None")}); 
        for (myCounter = 0; myCounter < myNumberOfFiles; myCounter++){ 
            myFile = myFiles[myCounter]; 
            //alert(myFile);           
            myRectangle = myDocument.rectangles.item(myCounter);
            myRectangle.place(File(myFile));
                    for (var myCounter = myDocument.rectangles.length-1; myCounter >= 0;myCounter--){ 
                              if (myDocument.rectangles.item(myCounter).contentType == ContentType.unassigned){
                                        myDocument.rectangles.item(myCounter).remove();
                              else{
                                        //As soon as you encounter a rectangle with content, exit the loop.
                                        break;