Question 1

How to handle JavaScript-rendered sites with Crawler?

Accepted Answer

Crawler fetches JavaScript files but doesn't execute them. You'll need to implement a custom parser or integrate with a headless browser library like Hound or Wallaby to process dynamic content effectively.

Question 2

Crawler vs Floki for web scraping in Elixir?

Accepted Answer

Crawler is a full crawling library with concurrency, rate limiting, and pipeline building, while Floki is a lightweight HTML parser. Use Crawler for orchestrated scraping tasks and Floki for parsing HTML within or outside Crawler.

Question 3

How to set up rate limiting to avoid getting banned?

Accepted Answer

Configure the :interval option in milliseconds to add delays between requests. For example, set it to 1000 for one request per second, and use :retries for failed attempts, as detailed in the configurations table.

Question 4

Can Crawler automatically rotate proxies or handle CAPTCHAs?

Accepted Answer

No, Crawler lacks built-in support for proxy rotation or CAPTCHA solving. You must implement custom logic in a modifier or retrier module, which can add significant complexity.

Question 5

What's the best way to store crawled data for later analysis?

Accepted Answer

Crawler offers multiple storage methods: use Crawler.Store for in-memory access, save to disk with the :save_to option, or create a custom store module to integrate with databases like PostgreSQL or Redis.

Question 6

How to pause and resume a crawl without losing data?

Accepted Answer

Use Crawler.pause/1 and Crawler.resume/1 with the crawler options, but ensure :timeout is set to :infinity or a high value to prevent parser timeouts, as cautioned in the README's pause/resume section.

Crawler

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