Photoshop script to replace a smart object within a PSD with selected image(s) and save result as a JPG. (Transformations to the smart object will be applied to new images).

replace_smartobject_image.js

// Replace SmartObject’s Content and Save as JPG
// 2017, use it at your own risk
// Via @Circle B: https://graphicdesign.stackexchange.com/questions/92796/replacing-a-smart-object-in-bulk-with-photoshops-variable-data-or-scripts/93359
// JPG code from here: https://forums.adobe.com/thread/737789

#target photoshop
if (app.documents.length > 0) {
    var myDocument = app.activeDocument;
    var theName = myDocument.name.match(/(.*)\.[^\.]+$/)[1];
    var thePath = myDocument.path;
    var theLayer = myDocument.activeLayer;
    // JPG Options;
    jpgSaveOptions = new JPEGSaveOptions();  
    jpgSaveOptions.embedColorProfile = true;  
    jpgSaveOptions.formatOptions = FormatOptions.STANDARDBASELINE;  
    jpgSaveOptions.matte = MatteType.NONE;  
    jpgSaveOptions.quality = 8;   
    // Check if layer is SmartObject;
    if (theLayer.kind != "LayerKind.SMARTOBJECT") {
        alert("selected layer is not a smart object")
    } else {
        // Select Files;
        if ($.os.search(/windows/i) != -1) {
            var theFiles = File.openDialog("please select files", "*.psd;*.tif;*.jpg", true)
        } else {
            var theFiles = File.openDialog("please select files", getFiles, true)
        };
        if (theFiles) {
            for (var m = 0; m < theFiles.length; m++) {
                // Replace SmartObject
                theLayer = replaceContents(theFiles[m], theLayer);
                var theNewName = theFiles[m].name.match(/(.*)\.[^\.]+$/)[1];
                // Save JPG. If you have need of saving different artboards into separate files,
                // see https://gist.github.com/laryn/0a1f6bf0dab5b713395a835f9bfa805c#gistcomment-3996733
                myDocument.saveAs((new File(thePath + "/" + theName + "_" + theNewName + ".jpg")), jpgSaveOptions, true,Extension.LOWERCASE);
            }
        }
    }
};
// Get PSDs, TIFs and JPGs from files
function getFiles(theFile) {
    if (theFile.name.match(/\.(psd|tif|jpg)$/i) != null || theFile.constructor.name == "Folder") {
        return true
    };
};
// Replace SmartObject Contents
function replaceContents(newFile, theSO) {
    app.activeDocument.activeLayer = theSO;
    // =======================================================
    var idplacedLayerReplaceContents = stringIDToTypeID("placedLayerReplaceContents");
    var desc3 = new ActionDescriptor();
    var idnull = charIDToTypeID("null");
    desc3.putPath(idnull, new File(newFile));
    var idPgNm = charIDToTypeID("PgNm");
    desc3.putInteger(idPgNm, 1);
    executeAction(idplacedLayerReplaceContents, desc3, DialogModes.NO);
    return app.activeDocument.activeLayer
};

To replace a smart object within a PSD with selected image(s) and save the result as a JPG using a Photoshop script, you can refer to the detailed instructions provided in the article on BulkMockup. The article covers the use of scripts to automate the process and includes steps for replacing smart objects in bulk. The script mentioned in the article applies transformations to the smart objects and ensures that the changes are saved as JPG files.

@shohidur333
My new versions actually does this, I've implemented 2 version now. One which edit the link itself, the other will edit the content inside the smartobject. The latter is slower however to the workflow need. But it's still a fraction of doing this all manually .

It's nice you have such expanded tutorials and writing. But it's a commercial product. $15 per month. Kinda steep price if you can get ir for free here