Does Scraper (Rust) have any limitations in terms of website complexity?

scraper is a Rust crate (library) for parsing HTML using the html5ever parsing engine, which is based on the HTML parsing algorithm implemented in the Servo browser engine. It provides a way to select and manipulate HTML elements using CSS selectors. As with any web scraping tool, scraper does have its limitations when it comes to the complexity of websites it can handle effectively. Here are some of the limitations and challenges you might encounter when using scraper for complex websites:

1. Dynamic Content: Websites that heavily rely on JavaScript to load and display content dynamically can pose a challenge for scraper. Since scraper only parses static HTML content, it cannot execute JavaScript. This means any content or changes to the DOM made through JavaScript after the initial page load will not be accessible.

2. Complex JavaScript Logic: Some websites use complex JavaScript to manipulate content, handle user interactions, or implement security measures. scraper cannot interpret or execute this JavaScript, which means it is unable to interact with such websites in the same way a browser or a headless browser automation tool like Puppeteer or Selenium can.

3. Session Handling: Websites that require session handling, cookies, or headers to maintain state between page requests can be more challenging to scrape. While scraper itself doesn't handle these directly, you can manage sessions and cookies using Rust's HTTP client libraries like reqwest, and then pass the resulting HTML to scraper.

4. Rate Limiting and Bot Detection: Many websites implement measures to detect and block automated scraping. These include rate limiting, CAPTCHAs, and more sophisticated bot detection algorithms. scraper does not have built-in capabilities to bypass such measures, and attempting to scrape such websites without proper handling could lead to your IP being blocked.

5. Complex CSS Selectors: While scraper does support a range of CSS selectors, certain pseudo-classes and pseudo-elements that are available in modern browsers may not be supported. This could limit the granularity with which you can select elements on a page.

6. Error Handling: Robust error handling is crucial for dealing with network issues, malformed HTML, and changes in website structure. scraper provides some tools for this, but it's up to the developer to handle these cases appropriately, which can be more complex for dynamic or frequently changing websites.

7. Performance: Parsing large or complex HTML documents and running many CSS selectors can be resource-intensive. scraper is generally fast due to the performance characteristics of Rust and the efficiency of html5ever, but performance may still be a consideration for very large-scale scraping tasks.

8. Documentation and Community Support: While scraper has documentation, it might not be as extensive as some other scraping libraries in more widely-used languages like Python's BeautifulSoup or Scrapy. The community around Rust web scraping is growing, but it may not be as large or as active as in other languages, which can impact the support available for complex scraping tasks.

Despite these limitations, scraper can be a powerful tool for scraping tasks where the content is served as static HTML. For more complex scraping needs involving dynamic content, you might need to pair scraper with a headless browser or use alternative solutions that can execute JavaScript and handle complex interactions with web pages.