Question

const express = require('express');
const fs = require('fs');
const readLine = require('readline')
const app = express();
const port = 3000;

app.get('/', (req, res, next) => {

  let aylinResponseArray = [];
  let sendLine = readLine.createInterface({
    input: fs.createReadStream('my-file.txt'),
  });

sendLine.on('line', (line) => {
//multiple async API calls made here, I push response on my API's done callback.
}).on('close', function() {
console.log('finished');
  });
  res.end();
});

当我进入端点并运行它时，我先完成了一切。显然，我没有正确使用异步/等待原则，很高兴收到您的经验。

我尝试了不同的方法，发现了一种与我要寻找的方法接近的方法：

const { once } = require('events');
const { createReadStream } = require('fs');
const { createInterface } = require('readline');

(async function processLineByLine() {
  try {
    const rl = createInterface({
      input: createReadStream('big-file.txt'),
      crlfDelay: Infinity
    });

    rl.on('line', (line) => {
      // Process the line.
    });

    await once(rl, 'close');

    console.log('File processed.');
  } catch (err) {
    console.error(err);
  }
})();

但是我收到来自节点的转码错误，指出该once is not a function。

我只是将以上内容作为试用版提供，如果您对以上代码有更简单的解决方案，请告诉我

带有异步API调用的节点readline，如何知道何时关闭（）

0 个答案: