PNGExport.jsx

// v1.2
// Set Resolution here
var width = 1920;

// Enter export prefix if you dont want to be prompted
var exportName = "";

// Default Prompt Value
var defaultExportPrefix = "Export";

// Function to set the export to PNG
function exportFileToPNG(dest, artBoardIndex, scaleTo)
{
    var exportOptions = new ExportOptionsPNG24(); // or ExportOptionsPNG8
    var type = ExportType.PNG24; // or ExportType.PNG8
    var file = new File(dest + ".png");

    exportOptions.artBoardClipping = true;
    exportOptions.antiAliasing = true;
    exportOptions.transparency = true;
    exportOptions.verticalScale = scaleTo;
    exportOptions.horizontalScale = scaleTo;
    exportOptions.qualitySetting = 72;
    exportOptions.saveMultipleArtboards = false;
    exportOptions.artboardRange = "" + artBoardIndex;
    app.activeDocument.exportFile( file, type, exportOptions );
}

// Main Function
function execute()
{

    if (app.documents.length == 0)
    {
        alert('No document open', 'Error');
        return;
    }

    
    if (app.activeDocument.selection.length == 0)
    {
        alert('Nothing selected', 'Error');
        return;
    }


    // determine destination
    var docRef = app.activeDocument;
    var destFolder = docRef.path;
    if(destFolder == ""){
        destFolder = Folder.selectDialog('Select the folder to export to:');
    }

    if (exportName == "") {
        exportName = prompt("Please enter target file name prefix", defaultExportPrefix);
    };

    // Loop through the selection and export selected
    for (var i=0; i< app.activeDocument.selection.length; i++)
    {
        
        // Set selected stuff for easy naming
        var selectedStuff = app.activeDocument.selection[i];

        // Remember original position
        var oldPosition = selectedStuff.position;

        // snap position to pixels
        selectedStuff.position = [ Math.round(selectedStuff.position[0]), Math.round(selectedStuff.position[1]) ];

        // create temporary artboad for exporting        
        try
        {
            var rect = selectedStuff.visibleBounds;
            docRef.artboards.add(rect);
            var scaleTo = width / (rect[2] - rect[0]) * 100;
        }
        catch(e)
        {
            alert(e);
            alert('Could not create Artboard as step of export.', 'Failure');

            //Restore old position
            selectedStuff.position = oldPosition
            return;
        }

        if(destFolder)
        {
            try
            {
                exportFileToPNG(destFolder + "/" + exportName + "_" + docRef.name + "_" +  i, docRef.artboards.length, scaleTo);
            }
            catch(e) {}
        }

        //Restore position
        selectedStuff.position = oldPosition

        // delete temp-artboard
        docRef.artboards.remove(docRef.artboards.length - 1);
    }
}

execute();