Skipping navigations for certain requests

While crawling a website, you may encounter certain resources you'd like to save, but don't need the full power of a crawler to do so (like images delivered through a CDN).

By combining the Request#skipNavigation option with sendRequest, we can fetch the image from the CDN, and save it to our key-value store without needing to use the full crawler.

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For this example, we are using the PlaywrightCrawler to showcase this, but this is available on all the crawlers we provide.

import { PlaywrightCrawler, KeyValueStore } from 'crawlee';

// Create a key value store for all images we find
const imageStore = await KeyValueStore.open('images');

const crawler = new PlaywrightCrawler({
    async requestHandler({ request, page, sendRequest }) {
        // The request should have the navigation skipped
        if (request.skipNavigation) {
            // Request the image and get its buffer back
            const imageResponse = await sendRequest({ responseType: 'buffer' });

            // Save the image in the key-value store
            await imageStore.setValue(`${request.userData.key}.png`, imageResponse.body);

            // Prevent executing the rest of the code as we do not need it
            return;
        }

        // Get all the image sources in the current page
        const images = await page.$$eval('img', (imgs) => imgs.map((img) => img.src));

        // Add all the urls as requests for the crawler, giving each image a key
        await crawler.addRequests(images.map((url, i) => ({ url, skipNavigation: true, userData: { key: i } })));
    },
});

await crawler.addRequests(['https://crawlee.dev']);

// Run the crawler
await crawler.run();