/I/want/title/?address=google.com&address=www.dawn.com/events/

I have multiple query param in a URL and I want to fetch the title from each and show them as a list inside an HTML page. My question is how can I store the parsed response outside this map so I can somehow make a list and send back a response.

const parseTitle = (body) => {
  let match = body.match(/<title>(.*?)<\/title>/);
  if (!match || typeof match[1] !== "string") "Title Not FOund";
  return match[1];
};

app.get("/I/want/title/", (req, res) => {
  const query = url.parse(req.url, true).query;
  if (!query.address) {
    res.status(400).send("Missing url query parameter");
  }
  const list = typeof query.address === "string" ? [query.address] : query.address;
  list.map((address) => {
    axios
      .get(address)
      .then((res) => res.data)
      .then((body) => {
        console.log(`${address} -- ${parseTitle(body)}`);
      })
      .catch((error) => {
        console.error(`${address} --  NO RESPONSE`);
      });
  });

  res.send();
});

CodePudding user response：

I expanded upon @Leon Braun answer :

const express = require('express');
const url = require('url');
const axios = require('axios');
const app = express();

const parseTitle = (body) => {
  let match = body.match(/<title>(.*?)<\/title>/);
  if (!match || typeof match[1] !== "string") "Title Not FOund";
  return match[1];
};

app.get("/I/want/title/", (req, res) => {
  const results = [];
  const query = url.parse(req.url, true).query;
  if (!query.address) {
    res.status(400).send("Missing url query parameter");
  }
  const list = typeof query.address === "string" ? [query.address] : query.address;
  list.map((address) => {
    results.push(axios.get(address).then((res) => {
      return `${address} -- ${parseTitle(res.data)}`
    }));
  });

  let response = '';
  Promise.all(results).then((resolved) => {
    resolved.forEach((s) => {
      response = response   s;
    })
    res.send(response);
  })
});

app.listen(3000);

You use then to return the data you want and wait for all promises with Promise.all, and you only send the response when you have your data

CodePudding user response：

Just define a array above your list.mapstatement and push the results into it.

const results = [];
// Inside your list.map()
results.push('A title');

Edit: @LK77 mentioned that you have to await the axios request. I would suggest that you read about async/await syntax first. Always remember, every function that returns a promise will be executed async. That means, if you need the data, you have to wait for it.