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dataflowkitvscrwlr-crawler

BSD-3-Clause 4 3 641
Feb 09 2017 2024-04-04(a day ago)
298 2 2 MIT
v1.7.2(17 days ago) Apr 18 2022 12 (month)

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.
  • S—Āraping 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.

This library provides kind of a framework and a lot of ready to use, so-called steps, that you can use as building blocks, to build your own crawlers and scrapers with.

Some features: - Crawler Politeness innocent (respecting robots.txt, throttling,...) - Load URLs using - a (PSR-18) HTTP client (default is of course Guzzle) - or a headless browser (chrome) to get source after Javascript execution - Get absolute links from HTML documents link - Get sitemaps from robots.txt and get all URLs from those sitemaps - Crawl (load) all pages of a website spider - Use cookies (or don't) cookie - Use any HTTP methods (GET, POST,...) and send any headers or body - Iterate over paginated list pages repeat - Extract data from: - HTML and also XML (using CSS selectors or XPath queries) - JSON (using dot notation) - CSV (map columns) - Extract schema.org structured data in JSON-LD format from HTML documents - Keep memory usage low by using PHP Generators muscle - Cache HTTP responses during development, so you don't have to load pages again and again after every code change - Get logs about what your crawler is doing (accepts any PSR-3 LoggerInterface)

Example Use


Dataflowkit uses JSON configuration like:
{
  "name": "collection",
  "request": {
      "url": "https://example.com"
  },
  "fields": [
      {
          "name": "Title",
          "selector": ".product-container a",
          "extractor": {
              "types": [
                  "text",
                  "href"
              ],
              "filters": [
                  "trim",
                  "lowerCase"
              ],
              "params": {
                  "includeIfEmpty": false
              }
          }
      },
      {
          "name": "Image",
          "selector": "#product-container img",
          "extractor": {
              "types": [
                  "alt",
                  "src",
                  "width",
                  "height"
              ],
              "filters": [
                  "trim",
                  "upperCase"
              ]
          }
      },
      {
          "name": "Buyinfo",
          "selector": ".buy-info",
          "extractor": {
              "types": [
                  "text"
              ],
              "params": {
                  "includeIfEmpty": false
              }
          }
      }
  ],
  "paginator": {
      "selector": ".next",
      "attr": "href",
      "maxPages": 3
  },
  "format": "json",
  "fetcherType": "chrome",
  "paginateResults": false
}
which is then ingested through CLI command.
<?php
require_once 'vendor/autoload.php';

use Crwlr\Crawler;

$crawler = new Crawler();
$crawler->get('https://example.com', ['User-Agent' => 'webscraping.fyi']);


// more links can be followed:
$crawler->followLinks();

// and current page can be parsed:
$response = $crawler->response();
$title = $crawler->filter('title')->text();
echo $response->getContent();
```

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