CODEWITHSUNDEEP
javascriptnode.jsexpressasync-awaitnode-promisify
Gattaccio7
Gattaccio7

Reputation: 97

Promisify Express response.render method

I need to create a render method to build html blocks into a string. It seems to work but I used the notorious "new Promise" and I wanted to know if what I've done is either correct or not:

async render(req, res) {
  const locals = await this.execute(req); // DB operation, retrieve context
  return new Promise((resolve, reject) => {
    try {
      return res.render('my-view', { ...locals, layout: null }, (err, html) => { 
        if (err) {
          return reject(err);
        }
        return resolve(html);
      });
    } catch (err) {
      return reject(err);
    }
  });
}

Thank you!

Upvotes: 0

Views: 168

Answers (1)

Bergi
Bergi

Reputation: 665155

The new Promise constructor implicitly catches (synchronous) exceptions from the executor callback, so that try/catch is not needed. Also, the return value is ignored. You'd write just

async render(req, res) {
  const locals = await this.execute(req); // DB operation, retrieve context
  return new Promise((resolve, reject) => {
    res.render('my-view', { ...locals, layout: null }, (err, html) => { 
      if (err) reject(err);
      else resolve(html);
    });
  });
}

Upvotes: 1

Related Questions