vsemozhetbyt ( Vse Mozhet Byt )

puppeteer can transfer two types of data between Node.js and browser context: serializable data (i.e. data that is supported by JSON.stringify()/JSON.parse()) and JavaScript object ids (including DOM elements) — JSHandle and ElementHandle. Later ones have a bit more complicated API (see JSHandle and ElementHandle methods or methods that mention them).

page.evaluate() can only transfer serializable data, and instead of un-serializable data, it returns undefined or empty objects. DOM elements are non-serializable as they contain circular references and methods.

So if you just need some text or element attributes, try to do most of the processing in the browser context and return just serializable data.

const result = await page.evaluate(() => Array.from(
  document.querySelectorAll('.u-vr4x'),
  element => element.innerText
);
console.log(result);

ballfam

comment created time in 2 days

issue commentnodejs/help

Need help converting code to callback function or async/await

For starters, I can suggest these two ways, with a callback or async/await. If you need some more explanation, please ask)

With a callback.

// module.js

function getChanID(chanType, callback) {
  db.getConnection((err, con) => {
    con.query(`SELECT * FROM channels WHERE type = '${chanType}'`, (err, rows) => {
      if (err) throw err;

      const chanID = rows[0].id;
      con.release();
      callback(chanID);
    });
  });
}

module.exports = {
  getChanID,
};

// main.js

const { getChanID } = require('./module.js');

const chanType = 'foo';

getChanID(chanType, processChanID);

function processChanID(chanID) {
  console.log(chanID);
  // Other code using chanID.
}

With async/await.

// module.js

function getChanID(chanType) {
  return new Promise((resolve, reject) => {
    db.getConnection((err, con) => {
      con.query(`SELECT * FROM channels WHERE type = '${chanType}'`, (err, rows) => {
        if (err) {
          reject(err);
        } else {
          const chanID = rows[0].id;
          con.release();
          resolve(chanID);
        }
      });
    });
  });
}

module.exports = {
  getChanID,
};

// main.js

const { getChanID } = require('./module.js');

(async function main() {
  try {
    const chanType = 'foo';

    const chanID = await getChanID(chanType);

    console.log(chanID);
    // Other code using chanID.
  } catch (err) {
    console.error(err);
  }
})();

Syntthetix

comment created time in 3 days

issue closednodejs/node-v8

Last versions lack some binaries

Last full build: https://nodejs.org/download/v8-canary/v15.0.0-v8-canary202006192e28363093/

Deficient builds: https://nodejs.org/download/v8-canary/v15.0.0-v8-canary202006254d76a1d646/ https://nodejs.org/download/v8-canary/v15.0.0-v8-canary2020062643c97a74f2/

closed time in 4 days

vsemozhetbyt

issue commentnodejs/node-v8

Last versions lack some binaries

Closing for now as we have no binaries at all for the last 10 days.

vsemozhetbyt

comment created time in 4 days

issue commentrauschma/impatient-js

Chapter: Single objects

25.6.9.4 A polyfill for Object.fromEntries()