Photoshop script to replace a Smart Object within a PSD using "Place Embedded" with specified image and saves result as a JPG. Preserves transformations.

replace_smartobject_psd_placeembedded.jsx

// Photoshop script to replace a Smart Object within a PSD using "Place Embedded" with specified image and saves result as a JPG. Preserves transformations.
// 2025. Use at your own risk

// Can be run in an automated fashion on Mac via AppleScript:
// osascript -e "tell application \"Adobe Photoshop 2025\" to activate do javascript of file \"replace_smartobject_psd_placeembedded.jsx\""

#target photoshop

var mockupFilePath = "~/mockup.psd";
var designFilePath = "~/design.png";
var exportFilePath = "~/export.jpg";

var jpegOptions = new JPEGSaveOptions();
jpegOptions.quality = 9;
jpegOptions.embedColorProfile = true;
jpegOptions.matte = MatteType.NONE;

app.open(new File(mockupFilePath));

var myDocument = app.activeDocument;
var theName = myDocument.name.match(/(.*)\.[^\.]+$/)[1];
var thePath = myDocument.path;

var smartObject = findSmartObject(app.activeDocument);
var theLayer = smartObject;
myDocument.activeLayer = theLayer;

if (theLayer.kind != "LayerKind.SMARTOBJECT") {
  alert("selected layer is not a smart object");
} else {
  theLayer = editSmartObjectAndPlaceEmbedded(designFilePath, theLayer);
  myDocument.saveAs(new File(exportFilePath), jpegOptions, true);
  app.activeDocument.close(SaveOptions.DONOTSAVECHANGES);
}

function findSmartObject(doc) {
  try {
    // Find all smart objects in the document
    var smartObjects = findSmartObjects(doc);

    if (smartObjects.length === 0) {
      alert("No smart objects found in the document.");
      return;
    }

    // If multiple smart objects exist, let user choose which one to replace
    var targetSmartObject;
    if (smartObjects.length === 1) {
      targetSmartObject = smartObjects[0];
    } else {
      // For multiple smart objects, select the first one
      // You can modify this logic to let user choose specific smart object
      targetSmartObject = smartObjects[0];
      alert("Multiple smart objects found. Using the first one.");
    }

    return targetSmartObject;
  } catch (error) {
    throw new Error("Failed to replace smart object content: " + error.message);
  }
}

function findSmartObjects(doc) {
  var smartObjects = [];

  try {
    // Search through all layers recursively
    function searchLayers(layers) {
      for (var i = 0; i < layers.length; i++) {
        var layer = layers[i];

        // Check if layer is a smart object
        if (layer.kind === LayerKind.SMARTOBJECT) {
          smartObjects.push(layer);
        }

        // If layer is a group, search its layers
        if (layer.typename === "LayerSet") {
          searchLayers(layer.layers);
        }
      }
    }

    searchLayers(doc.layers);
  } catch (error) {
    throw new Error("Error searching for smart objects: " + error.message);
  }

  return smartObjects;
}

function editSmartObjectAndPlaceEmbedded(newFile, smartObjectLayer) {
  try {
    // Store reference to the main document
    var mainDocument = app.activeDocument;

    // Edit the smart object contents using ActionDescriptor
    editSmartObjectContents(smartObjectLayer);

    // Now we're inside the smart object document
    var smartObjectDoc = app.activeDocument;

    // Clear existing content (optional - you can modify this based on your needs)
    // smartObjectDoc.layers[0].delete();

    // Place the new file as embedded
    placeEmbedded(newFile);

    // Save changes to the smart object
    smartObjectDoc.save();

    // Close the smart object document and return to main document
    smartObjectDoc.close(SaveOptions.SAVECHANGES);

    // Return to the main document
    app.activeDocument = mainDocument;

    return smartObjectLayer;
  } catch (error) {
    alert("Error editing smart object: " + error.message);
    // Try to return to main document if there was an error
    try {
      app.activeDocument = mainDocument;
    } catch (e) {
      // If we can't return to main document, try to close any open smart object
      if (app.documents.length > 1) {
        app.activeDocument.close(SaveOptions.DONOTSAVECHANGES);
      }
    }
    throw error;
  }
}

function placeEmbedded(filePath) {
  var actDesc = new ActionDescriptor();
  actDesc.putPath(charIDToTypeID("null"), new File(filePath));
  actDesc.putEnumerated(
    charIDToTypeID("FTcs"),
    charIDToTypeID("QCSt"),
    charIDToTypeID("Qcsa")
  );
  executeAction(charIDToTypeID("Plc "), actDesc, DialogModes.NO);
}

function editSmartObjectContents(smartObjectLayer) {
  try {
    // Make the smart object layer active
    app.activeDocument.activeLayer = smartObjectLayer;

    // Use ActionDescriptor to edit smart object contents
    var desc = new ActionDescriptor();
    var ref = new ActionReference();
    ref.putEnumerated(
      charIDToTypeID("Lyr "),
      charIDToTypeID("Ordn"),
      charIDToTypeID("Trgt")
    );
    desc.putReference(charIDToTypeID("null"), ref);
    desc.putEnumerated(
      charIDToTypeID("Usng"),
      charIDToTypeID("Plc "),
      charIDToTypeID("Plc ")
    );
    executeAction(
      stringIDToTypeID("placedLayerEditContents"),
      desc,
      DialogModes.NO
    );
  } catch (error) {
    throw new Error("Failed to edit smart object contents: " + error.message);
  }
}