Question

我的目标是从NG2-webapp中正在运行的本地 ElasticSearch Server 中检索样本数据，然后显示这些结果。

到目前为止，我已使用NPM Elasticsearch Typescript package创建了一个组件test-es-types。

这是.ts代码：

  import { Component, OnInit } from '@angular/core';
  import * as elasticsearch from 'elasticsearch';

  @Component({
    selector: 'app-test-es-types',
    templateUrl: './test-es-types.component.html',
    styleUrls: ['./test-es-types.component.scss']
  })

  export class TestEsTypesComponent implements OnInit {

    constructor() { }

    ngOnInit() {

   // Setting up Elasticsearch Client
   var client = new elasticsearch.Client({
     host: 'http://localhost:9200',
     log: 'trace'
   });

   console.log("Client:", client);

  // Elasticsearch Server Ping
  client.ping({
  // ping usually has a 3000ms timeout
  requestTimeout: 1000
}, function (error) {
  if (error) {
    console.trace('elasticsearch cluster is down!');
  } else {
    console.log('All is well');
  }
});

// first we do a search, and specify a scroll timeout
var allTitles: string[] = [];
console.log("Erzeuge allTitles Array...");
client.search({
  index: 'bank',
  // Set to 30 seconds because we are calling right back
  scroll: '30s',
  searchType: 'query_then_fetch',
  docvalueFields: [''],
  q: 'Avenue'
}, function getMoreUntilDone(error, response) {
  // collect the first name from each response
  console.log("allTitles gefüllt: ", allTitles);
  response.hits.hits.forEach(function (hit) {
    allTitles.push(hit.fields.firstname);
  });

  if (response.hits.total !== allTitles.length) {
    // now we can call scroll over and over
    client.scroll({
      scrollId: response._scroll_id,
      scroll: '30s'
    }, getMoreUntilDone);
  } else {
    console.log('every "test" title', allTitles);
  }
});

}

}

ES-server在localhost：9200上运行，并按预期返回查询的数据（根据控制台）。但是，当尝试将此数据放入数组（allTitles）时，我收到以下控制台错误：

Uncaught TypeError: Cannot read property 'firstname' of undefined

console.log告诉我allTitles是空的（长度为0），所以显然不起作用。好像我还不了解将对象转换为数组的复杂性？

Answer 1

强烈建议不要直接从浏览器环境中使用弹性API。

https://github.com/elastic/elasticsearch-js/issues/905#issuecomment-582932779

Answer 2

一个可能的问题是您没有正确访问响应。尝试像

这样的东西

var data = [5,4,3,2,1];

for(var i = 0; i < data.length;) {
  if(data[i]>data[i+1]) {
      var temp = data[i];
      data[i] = data[i+1];
      data[i+1] = temp;
      i = 0;
  }else{
      i++;
  }
  console.log(data);
}

以下是quickstart guide以获取更多信息。

Angular2 + Elasticsearch：获取未定义的＆＃34;属性＆＃34;从Elasticsearch服务器计算检索到的JSON数据时出错

2 个答案: