Using ExtendScript to save out multiple resolution images from Photoshop (with unsharp mask)

psextendscriptexample.js

/* 
    The original files are 960x319.
    
    Image sizes to save:
    
    * 800x266 - Retina for 480x320 resolution (400 logical pixel wide panel areas)
    * 740x246 - Desktop and iPad
    * 616x205 - Retina for 320x480 resolution (308 logical pixel wide panel areas)
    * 400x133 - 480x320 resolution
    * 308x102 - 320x480 resolution
    
    The various states (each image) is in a layer comp.
    
    Process:
   
    1. Loop through the image sizes.
    -- 2. Save history state.
    -- 3. Resize to the current image size.
    -- 4. Loop through layers
    ---- 5. Apply unsharp mask
    -- 6. Loop through layer comps
    ---- 7. Save image
    -- 8. Restore the history state to return to the full-sized image.
        
*/

var docRef = app.activeDocument;

var layerComps = docRef.layerComps;
var numLayerComps = layerComps.length;
var layers = docRef.layers;
var numLayers = layers.length;

var imageSizes = [
    ["800px", "266px"],
    ["740px", "246px"],
    ["616px", "205px"],
    ["400px", "133px"],
    ["308px", "102px"]
];

var exportOptionsSaveForWeb = new ExportOptionsSaveForWeb();
exportOptionsSaveForWeb.format = SaveDocumentType.JPEG;
exportOptionsSaveForWeb.includeProfile = true;
exportOptionsSaveForWeb.quality = 70;

parentFolderPath = Folder(app.activeDocument.fullName.parent).fsName;

// 1. Loop through the image sizes.
var numImageSizes = imageSizes.length;
for (var i = 0; i < numImageSizes; i++) {
    var currentImageSize = imageSizes[i];
    var currentImageWidth = currentImageSize[0];
    var currentImageHeight = currentImageSize[1];
    
    // 2. Save the history state.
    var savedState = docRef.activeHistoryState;
    
    // 3. Resize to the current image size.
    docRef.resizeImage(currentImageWidth, currentImageHeight);
    
    // 4. Loop through layers
    for (var j = 0; j < numLayers; j++) {
       var currentLayer = layers[j];
       
       if (currentLayer.name == "Overlay") {
           $.writeln("Not going to unsharp mask the overlay.");
           continue;
       }
       
       //  5. Apply unsharp mask
       currentLayer.visible = true;
       // $.writeln("About to unsharp mask: " + currentLayer.name);
       currentLayer.applyUnSharpMask(50, 1.1, 1);
    }

    // 6. Loop through layer comps
    for (var k = 0; k < numLayerComps; k++) {
        var currentLayerComp = layerComps[k];
        currentLayerComp.apply();
        
        var documentPath = parentFolderPath + "/images/" + docRef.name.substr(0, docRef.name.length - 4) + "-" + currentLayerComp.name + "-" + currentImageWidth + ".jpg";
        var file = new File(documentPath);
        
        // $.writeln("About to save: " + documentPath);
        
        // 7. Save image
        docRef.exportDocument (file, ExportType.SAVEFORWEB, exportOptionsSaveForWeb)
    }
    
    // 8. Restore the history state to return to the full-sized image.
    docRef.activeHistoryState = savedState;
    
}

Have you had any issues with this not creating the folders/files? It runs, I can see it resizing the canvas, but its not saving anything. Any thoughts? - The script gets to step 6, but $.writeln(numLayerComps); returns 0.