gistfile1.txt

  // This function will render the uploaded image in a dynamically generated <img> tag to preview to the user.
  gform.addFilter('gform_file_upload_markup', function (html, file, up, strings) {

    // @TODO - Update this url for dev, staging, production server.
    var myFilePath = 'https://s3-eu-west-2.amazonaws.com/influx-media/uploads/gravity_forms/9-57660a16a91c9efdb7ff52f24ff6f0b4/tmp/';
    
    var formId = up.settings.multipart_params.form_id,
    fieldId = up.settings.multipart_params.field_id;
    
    var fileName = up.settings.multipart_params.gform_unique_id + '_input_' + fieldId +'_'+ file.target_name;

    html = "<span class='gallery-image-preview-thumb gallery-image-preview-thumb--media' style='background-image:url(" + myFilePath + fileName + ")';><div class='gform_delete close-icon close-icon__gallery-image-edit-form' onclick='gformDeleteUploadedFile(" + formId + "," + fieldId + ", this);' alt='" + strings.delete_file + "' title='" + strings.delete_file + "'></div></span>";
    return html;
  });