I have urls of pdf file. ex:
const filesUrl= ["http://example.com/animal.pdf", "https://example.com/fruit.pdf", "http://example.com/stars.pdf"]
I want to download that files and save it to my server folder using puppeteer.
What im doing is:
But i have error: [ERR_INVALID_CALLBACK]: Callback must be a function. Received undefined
If i look at the browser, the looping is not waiting until the page is fully loaded.
this is my code:
const filesUrl = await page.$$eval("li.b_algo h2 a", urls => {
return urls.map(url => url.href)
})
// filesUrl = ["http://example.com/animal.pdf", "https://example.com/fruit.pdf", "http://example.com/stars.pdf"]
for (const fileUrl of filesUrl) {
try {
const filepage = await page.goto(fileUrl)
await fs.writeFile(Math.random() + ".pdf", await filepage.buffer())
} catch (error) {
console.log('errorsadasd:', error);
}
}
await browser.close()
The error is not related to the puppeteer, but to the fs.writeFile, which requires a callback as an argument, which is missing, i.e. undefined, hence the error.
Try adding the callback:
await fs.writeFile(Math.random() + ".pdf", await filepage.buffer(), () => {
console.log('done writing file');
});
Try using writeFile, but wrapped in a promise:
import fs from 'fs';
const fsPromises = fs.promises;
const writeFilePromise = fsPromises.writeFile;
await writeFilePromise(Math.random() + ".pdf", await filepage.buffer());