dataflowkitvsmechanize
Dataflow kit ("DFK") is a Web Scraping framework for Gophers. It extracts data from web pages, following the specified CSS Selectors. You can use it in many ways for data mining, data processing or archiving.
Web-scraping pipeline consists of 3 general components:
- Downloading an HTML web-page. (Fetch Service)
- Parsing an HTML page and retrieving data we're interested in (Parse Service)
- Encoding parsed data to CSV, MS Excel, JSON, JSON Lines or XML format.
For fetching dataflowkit has several types of page fetchers:
- Base fetcher uses standard golang http client to fetch pages as is. It works faster than Chrome fetcher. But Base fetcher cannot render dynamic javascript driven web pages.
- Chrome fetcher is intended for rendering dynamic javascript based content. It sends requests to Chrome running in headless mode.
For parsing dataflowkit extracts data from downloaded web page following the rules listed in configuration JSON file. Extracted data is returned in CSV, MS Excel, JSON or XML format.
Some dataflowkit features:
- Scraping of JavaScript generated pages;
- Data extraction from paginated websites;
- Processing infinite scrolled pages.
- Sсraping of websites behind login form;
- Cookies and sessions handling;
- Following links and detailed pages processing;
- Managing delays between requests per domain;
- Following robots.txt directives;
- Saving intermediate data in Diskv or Mongodb. Storage interface is flexible enough to add more storage types easily;
- Encode results to CSV, MS Excel, JSON(Lines), XML formats;
- Dataflow kit is fast. It takes about 4-6 seconds to fetch and then parse 50 pages.
- Dataflow kit is suitable to process quite large volumes of data. Our tests show the time needed to parse appr. 4 millions of pages is about 7 hours.
Mechanize is a Ruby library for automating interaction with websites. It automatically stores and sends cookies, follows redirects, and can submit forms — making it behave like a web browser without needing an actual browser engine.
Key features include:
- Automatic cookie management Stores cookies received from servers and sends them back on subsequent requests, maintaining session state across multiple pages.
- Form handling Can find, fill in, and submit HTML forms programmatically. Supports text inputs, selects, checkboxes, radio buttons, and file uploads.
- Link following Navigate through pages by clicking links using their text content, CSS selectors, or href patterns.
- History and back/forward Maintains a browsing history, allowing you to go back and forward through visited pages.
- HTTP authentication Supports basic and digest HTTP authentication.
- Proxy support Can route requests through HTTP proxies.
- Redirect handling Automatically follows HTTP redirects (configurable).
Mechanize is one of the oldest and most established web interaction libraries in Ruby. It is best suited for scraping traditional server-rendered websites with forms and multi-page workflows. For JavaScript-heavy sites, a browser automation tool like Selenium or Playwright is recommended instead.