Spaces:
Running
Running
| # Tutorial: Clicking Buttons to Load More Content with Crawl4AI | |
| ## Introduction | |
| When scraping dynamic websites, it’s common to encounter “Load More” or “Next” buttons that must be clicked to reveal new content. Crawl4AI provides a straightforward way to handle these situations using JavaScript execution and waiting conditions. In this tutorial, we’ll cover two approaches: | |
| 1. **Step-by-step (Session-based) Approach:** Multiple calls to `arun()` to progressively load more content. | |
| 2. **Single-call Approach:** Execute a more complex JavaScript snippet inside a single `arun()` call to handle all clicks at once before the extraction. | |
| ## Prerequisites | |
| - A working installation of Crawl4AI | |
| - Basic familiarity with Python’s `async`/`await` syntax | |
| ## Step-by-Step Approach | |
| Use a session ID to maintain state across multiple `arun()` calls: | |
| ```python | |
| from crawl4ai import AsyncWebCrawler, CacheMode | |
| js_code = [ | |
| # This JS finds the “Next” button and clicks it | |
| "const nextButton = document.querySelector('button.next'); nextButton && nextButton.click();" | |
| ] | |
| wait_for_condition = "css:.new-content-class" | |
| async with AsyncWebCrawler(headless=True, verbose=True) as crawler: | |
| # 1. Load the initial page | |
| result_initial = await crawler.arun( | |
| url="https://example.com", | |
| cache_mode=CacheMode.BYPASS, | |
| session_id="my_session" | |
| ) | |
| # 2. Click the 'Next' button and wait for new content | |
| result_next = await crawler.arun( | |
| url="https://example.com", | |
| session_id="my_session", | |
| js_code=js_code, | |
| wait_for=wait_for_condition, | |
| js_only=True, | |
| cache_mode=CacheMode.BYPASS | |
| ) | |
| # `result_next` now contains the updated HTML after clicking 'Next' | |
| ``` | |
| **Key Points:** | |
| - **`session_id`**: Keeps the same browser context open. | |
| - **`js_code`**: Executes JavaScript in the context of the already loaded page. | |
| - **`wait_for`**: Ensures the crawler waits until new content is fully loaded. | |
| - **`js_only=True`**: Runs the JS in the current session without reloading the page. | |
| By repeating the `arun()` call multiple times and modifying the `js_code` (e.g., clicking different modules or pages), you can iteratively load all the desired content. | |
| ## Single-call Approach | |
| If the page allows it, you can run a single `arun()` call with a more elaborate JavaScript snippet that: | |
| - Iterates over all the modules or "Next" buttons | |
| - Clicks them one by one | |
| - Waits for content updates between each click | |
| - Once done, returns control to Crawl4AI for extraction. | |
| Example snippet: | |
| ```python | |
| from crawl4ai import AsyncWebCrawler, CacheMode | |
| js_code = [ | |
| # Example JS that clicks multiple modules: | |
| """ | |
| (async () => { | |
| const modules = document.querySelectorAll('.module-item'); | |
| for (let i = 0; i < modules.length; i++) { | |
| modules[i].scrollIntoView(); | |
| modules[i].click(); | |
| // Wait for each module’s content to load, adjust 100ms as needed | |
| await new Promise(r => setTimeout(r, 100)); | |
| } | |
| })(); | |
| """ | |
| ] | |
| async with AsyncWebCrawler(headless=True, verbose=True) as crawler: | |
| result = await crawler.arun( | |
| url="https://example.com", | |
| js_code=js_code, | |
| wait_for="css:.final-loaded-content-class", | |
| cache_mode=CacheMode.BYPASS | |
| ) | |
| # `result` now contains all content after all modules have been clicked in one go. | |
| ``` | |
| **Key Points:** | |
| - All interactions (clicks and waits) happen before the extraction. | |
| - Ideal for pages where all steps can be done in a single pass. | |
| ## Choosing the Right Approach | |
| - **Step-by-Step (Session-based)**: | |
| - Good when you need fine-grained control or must dynamically check conditions before clicking the next page. | |
| - Useful if the page requires multiple conditions checked at runtime. | |
| - **Single-call**: | |
| - Perfect if the sequence of interactions is known in advance. | |
| - Cleaner code if the page’s structure is consistent and predictable. | |
| ## Conclusion | |
| Crawl4AI makes it easy to handle dynamic content: | |
| - Use session IDs and multiple `arun()` calls for stepwise crawling. | |
| - Or pack all actions into one `arun()` call if the interactions are well-defined upfront. | |
| This flexibility ensures you can handle a wide range of dynamic web pages efficiently. | |