Unable to return a variable from a queued function about puppeteer-cluster HOT 4 CLOSED

@thomasdondorf thank you clearing up my misunderstanding. Apologies if it's a basic question, but I'm still not sure how one would go about returning pageTitle. Plain old, calling of pageTitle as a variable outside of the function didn't work.

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This is a misunderstanding regarding the Promise of the cluster.queue function. The Promise of the queue function resolves as soon as the job is queued, not when the job is finished.

This will change in Version 1. queue will not return a Promise anymore and there will be another function called execute which queues the data and waits until the job is finished.

For more discussion see #10

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All good :)

Right now you cannot return data from within the function, but instead you can collect it via an array in the outer scope like this:

const pageTitles = [];
const extractTitle = async ({ page, data: url }) => {
	await page.goto(url);
	const pageTitle = await page.evaluate(() => document.title);
	pageTitles.push(pageTitle);
};

// queue your pages

await cluster.idle(); // wait for the jobs to be finished

// pageTitles should now be filled with your page titles

Alternatively you could also use callbacks to collect your data (or create promises and use their resolve as callback).

Does that clear things up?

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@thomasdondorf yes this certainly helps to clear things up! Thank you for helping me out with this!

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