Bloodhound返回错误消息：无法读取未定义的属性'_id'

Question

我正在尝试使用datalake api配置搜索栏工作，但是一些如何使用bloodhound不能正常工作。我得到的最新错误是“无法读取未定义的属性'_id'”。这是我的代码：

var claritySearch = new Bloodhound({
    queryTokenizer: Bloodhound.tokenizers.whitespace,
    sufficient: 1,
    sorter: function(a, b) {
        },

    datumTokenizer: function(datum) {

  var tokens = [
    trimPRJ(datum._id),
    trimPrjAndZeros(datum._id),
    datum.wbsElement
  ];
  return tokens;
},

prefetch: {
  url: _dataLake.environment+'/CLARITY_SEARCH/projects/items?',
  cacheKey: "claritysearch",
  ttl: 14400000,
     prepare: function(settings){
        settings.beforeSend = function(jqXHR, settings){
            settings.xhrFields = {withCredentials: true};
            };
            settings.url = settings.url.replace();
            return settings;
            },
  transform: function(response) {
    return response.data;
  } 
},
remote: {
    url: _dataLake.environment+'/CLARITY_SEARCH/projects/items?', 
    prepare: function(query, settings) 
        settings.beforeSend = function(jqXHR, settings) {
            settings.xhrFields = { withCredentials: true };
          };
          settings.url = settings.url.replace('%QUERY', query),
    console.dir(settings);
    return settings;
   },
  transform: function(response) {
    return response.data;
    }
   }
  });