AssetProcessor

  void OnPreprocessAsset()
    {
        metaData = assetImporter.userData;
        filename = Path.GetFileNameWithoutExtension(assetPath);
        fileWithExt = Path.GetFileName(assetPath);
        assetsFolder = Application.dataPath;
        projectFolder = Directory.GetParent(assetsFolder);
        importFilePath = assetImporter.assetPath;
        fileCurrentTimestamp = WithoutMS(File.GetLastWriteTime(importFilePath));
        if (!EditorApplication.isPlaying)
        {
            if (assetPath.Contains(".xd"))
            {
                if (!metaData.Contains("alreadyImported: true"))
                {
                    if (EditorUtility.DisplayDialog("Parse Adobe Xd file to Unity?",
                        "Do you want to convert " + fileWithExt + " to Unity scenes?",
                        "Convert", "Add file to project as is"))
                    {
                        CoreImporter();
                    }

                }
                else if (metaData.Contains("alreadyImported: true"))
                {
                    string dateOf = "dateOfModification: ";
                    int from = metaData.IndexOf(dateOf) + dateOf.Length;
                    if (metaData.LastIndexOf("~;") > 0) fileLastTimeStamp = WithoutMS(DateTime.Parse(metaData.Substring(from, metaData.LastIndexOf("~;") - from)));
                    if (metaData.Contains("reimport: true;"))
                    {
                        ReimportAsset();
                        Selection.activeObject = AssetDatabase.LoadAssetAtPath<UnityEngine.Object>(assetPath);
                    }
                    else if (fileCurrentTimestamp > fileLastTimeStamp && !metaData.Contains("reimport: true;"))
                    {
                        if (EditorUtility.DisplayDialog("Reload imported file?",
                           "File " + fileWithExt + " has changed. Do you want to reload? All changes made in Unity will be lost.",
                           "Reload", "Keep current version"))
                        {
                            ReimportAsset();
                            Selection.activeObject = AssetDatabase.LoadAssetAtPath<UnityEngine.Object>(assetPath);
                        }
                    }
                }
            }

        }
        else
            Debug.LogWarning("Can't import Xd files in playmode");
    }

    public void ReimportAsset()
    {
        if (Directory.Exists(projectFolder + "/~Temp-" + filename)) Directory.Delete(projectFolder + "/~Temp-" + filename, true);
        if (Directory.Exists("Assets/Resources/[AdobeXd]-" + filename)) Directory.Delete("Assets/Resources/[AdobeXd]-" + filename, true);
        CoreImporter();
    }