Spidey ====== Spidey provides a bare-bones framework for crawling and scraping web sites. Its goal is to keep boilerplate scraping logic out of your code. Example ------- This example _spider_ crawls an eBay page, follows links to category pages, continues to auction detail pages, and finally records a few scraped item details as a _result_. class EbayPetSuppliesSpider < Spidey::AbstractSpider handle "http://pet-supplies.shop.ebay.com", :process_home def process_home(page, default_data = {}) page.search("#AllCats a[role=menuitem]").each do |a| handle resolve_url(a.attr('href'), page), :process_category, category: a.text.strip end end def process_category(page, default_data = {}) page.search("#ResultSetItems table.li td.dtl a").each do |a| handle resolve_url(a.attr('href'), page), :process_auction, default_data.merge(title: a.text.strip) end end def process_auction(page, default_data = {}) image_el = page.search('div.vi-ipic1 img').first price_el = page.search('span[itemprop=price]').first record default_data.merge( image_url: (image_el.attr('src') if image_el), price: price_el.text.strip ) end end spider = EbayPetSuppliesSpider.new verbose: true spider.crawl max_urls: 100 spider.results # => [{category: "Aquarium & Fish", title: "5 Gal. Fish Tank"... Implement a _spider_ class extending `Spidey::AbstractSpider` for each target site. The class can declare starting URLs by calling `handle` at the class level. Spidey invokes each of the methods specified in those calls, passing in the resulting `page` (a [Mechanize](http://mechanize.rubyforge.org/) [Page](http://mechanize.rubyforge.org/Mechanize/Page.html) object) and, optionally, some scraped data. The methods can do whatever processing of the page is necessary, calling `handle` with additional URLs to crawl and/or `record` with scraped results. Storage Strategies ---------- By default, the lists of URLs being crawled, results scraped, and errors encountered are stored as simple arrays in the spider (i.e., in memory): spider.urls # => ["http://www.ebay.com", "http://www.ebay.com/...", ...] spider.results # => [{auction_title: "...", sale_price: "..."}, ...] spider.errors # => [{url: "...", handler: :process_home, error: FooException}, ...] Add the [spidey-mongo](https://github.com/joeyAghion/spidey-mongo) gem and include `Spidey::Strategies::Mongo` in your spider to instead use MongoDB to persist these data. [See the docs](https://github.com/joeyAghion/spidey-mongo) for more information. Or, you can implement your own strategy by overriding the appropriate methods from `AbstractSpider`. Contributing ------------ Spidey is very much a work in progress. Pull requests welcome. To Do ----- * Spidey works well for crawling public web pages, but since little effort is undertaken to preserve the crawler's state across requests, it works less well when particular cookies or sequences of form submissions are required. [Mechanize](http://mechanize.rubyforge.org/) supports this quite well, though, so Spidey could grow in that direction. Copyright --------- Copyright (c) 2012 Joey Aghion, Art.sy Inc. See [LICENSE.txt](LICENSE.txt) for further details.