code: function convertAllObjectIdsToString(form) {
    form._id = form._id ? form._id.toString() : form._id;
    form.pages = _.map(form.pages, function(page) {
      page._id = page._id ? page._id.toString() : page._id;
  
      page.fields = _.map(page.fields, function(field) {
        field._id = field._id ? field._id.toString() : field._id;
        return field;
      });
  
      return page;
    });
    return form;
  }
docs: Handy Function To convert All ObjectIds to strings.