Announcing JscRUBYt! – no more win32 problems (?)

Posted by admin

 

Thanks to Paul Nikitochkin a.k.a. pftg, scRUBYt! made a great leap to ensure win32 compatibility. Paul created JscRUBYt! – the JRuby version of scRUBYt! which should be easy to install under win32 even if you are not a level 64 microsoft compiling ninja (in fact, it requires no compiling, fiddling around with C/C++ or doing anything outside (J)Ruby-land (well, except of installing JRuby, of course)).

Please download JscRUBYt! from here and read the installation instructions written up by Paul.

Please let us know if you run into any problems and/or your experience using this package!

 

Scrubyt.logger = Scrubyt::Logger.new
#your extractor begins here

Let the Dogs Out!

Posted by CopperMonkey

 

scRUBYt! has dug its way into the investment business :). No joke – check out this scrummy tutorial created by Doug Bromley to find out more.

A refreshing mix of business and technology is served here: a nice scraper that returns dividend yields summarized all in one place and a useful example for form filling and submitting, page navigation and constrains.

Thnx Doug for the excellent job!

 

require 'rubygems'
require 'scrubyt'

google_data = Scrubyt::Extractor.define do
  #Perform the action(s)
  fetch 'http://www.google.com/ncr'
  fill_textfield 'q', 'ruby'
  submit
  #Construct the wrapper
  link "Ruby Programming Language" do
    url "href", :type => :attribute
  end
  next_page "Next", :limit => 2
end

puts google_data.to_xml

Scraping pricegrabber.com with scRUBYt!

Posted by CopperMonkey

 

 

This is a new series on scraping different (hopefully typical) web pages to show off various scRUBYt! techniques. We will start of with a pricegrabber.com extractor. Check out the big picture to see what will we accomplish today!

 

You will see an example of:

• filling and submitting a textfield
• crawling to the detail pages of the results
• downloading images
• scraping desired data (text, price, user rating)

Goal:

• Go to http://cameras.pricegrabber.com.
• Enter ‘canon EOS 20D’ into the search textfield and submit the form.
• Download the item image from the detail page(s) and additional product information (like the lowest price) from the ‘Product Details’ tab.

Solution:

• Use the navigational commands ‘fetch’, ‘fill_textfield’, ’submit’ to navigate to the list page containing items related to the search term ‘canon EOS 20D’
• Crawl to the detail page by “clicking on” the link Canon EOS 20D Digital SLR Camera Body Only.
• Choose the detail tab ‘Product Details’ by cliking on it.
• Download the product image by providing its location’, ’src’ and finally setting a directory to download the images into using a ‘download’ pattern (note: you do not need to create the given directory, scRUBYt! does it for you! Look for it at the same location as your extractor is stored)
• Scrape the desired data (in this case Description and Lowest Price).
• Extract user rating with a regular expression.

The code:

require 'rubygems'
require 'scrubyt'

pricegrabber_data = Scrubyt:: Extractor.define do

  fetch 'http://cameras.pricegrabber.com'
  fill_textfield 'form_keyword', 'canon EOS 20D'
  submit

  camera 'Canon EOS 20D Digital SLR Camera Body Only', :generalize => false do
    camera_detail do
      detail_tab 'Product Details', :generalize => false do
        detail_detail do
          camera_record :generalize => false do
            image "http://ai.pricegrabber.com/pi/0/37/48/3748716_125.jpg" do
              image_url "src", :type => :attribute do
                download 'camera_images', :type => :download
              end
            end
            name 'EOS 20D Digital SLR Camera Body Only'
            lowestprice '$649.95'
            rating_and_reviews :contains => '(Read 31 Reviews)' do
              rating /(d.dd / d.dd)/
            end
          end
        end
      end
    end
  end
end

puts pricegrabber_data.to_xml

If you’d like to run, it cut’n’paste it from here (otherwise the code will be messed up).

If you are more of a visual type, check out this cart depicting the process.

Troubleshooting

Problem: “This extractor does not work!”

Solution: ‘Lowest Price’ changes quite frequently – check if the actual ‘Lowest Price’ at http://cameras.pricegrabber.com/digital/canon/m/3748716/details/ does match the one stated in the extractor. If not, simply “upgrade” the example with the actual correct data. Hmmm, this should work.

Problem: “The extractor returns data for the first listed item only. Where is the rest of data?”

Solution: The extractor was designed only to give a taste of how to solve similar scraping problems like it was stated in ‘Goals” therefore it is limited to the first item only. If you would like to scrape all the items on the list page simply remove :generalize => false from
“camera ‘Canon EOS 20D Digital SLR Camera Body Only’, :generalize => false do”. However, it will return data from the first list page only, while no crawling to the next pages is defined in the scraper (in our case it would be kind of insane since no next pages exist for this type of camera).

 

Ranking Ruby/Rails Blogs with scRUBYt! Using Alexa and Technorati

Posted by admin

 

As a (positive) side-effect of Ruby’s and RoR’s current popularity, we can witness the mushrooming of Ruby/Rails blogs of different size, shape, color and quality. While this is a great thing in general, it is easy to get overflooded with all this information pouring in from every side – much harder to pick a smaller set which you can monitor in your time devoted for reading Ruby blogs.

Fortunately there are some great Ruby/Rails blog aggregators like http://rubycorner.com/, http://www.planetrubyonrails.org/ – not to be confused with http://www.planetrubyonrails.com/ (here is why) or http://planet.caboo.se/.
The problem is that it’s clumsy to monitor all these aggregators – they contain hundreds of blogs each with a lot of overlapping.

This issue was partially solved by this Ruby on Rails Blog Aggregator Dupe Prevention yahoo pipe. However, there is a fundamental problem with that: You still have several hundreds of blogs – nearly 500 of them, and new ones coming out day by day. If you have time to read all these periodically, all the power to you – however, the rest of us would need a way to pick the top n ones in order to be able to cope with their reading.

I am proposing a solution for this problem, by performing these steps:

1. 1. Collecting all the blog URLs from the above 4 aggreagators
   2. Performing some data cleaning (e.g. http://www.site.com, http://site.com, http://site.com/blog and other variants, with and without trailing slashes are pointing to the same site) and dupe removal
   3. Querying http://www.alexa.com and http://www.technorati.com for the popularity of each of the blogs on the list (this already generated two rankings: “Alexa top 30″ and “Technorati top 30″.

Alexa required some intervention by hand (more on that later).

1. Putting it all together: based on the two top 30 lists, generate a final, all-in-one Ruby/Rails blog top 10!

Let’s see an overview of the process – then I will explain each step in detail!

Let’s begin with scraping http://www.planetrubyonrails.com/. This extractor was the easiest to construct of all the four:

    planet_ror_com_data = Scrubyt::Extractor.define do
      fetch("http://www.planetrubyonrails.com/pages/channels")

      link "http://weblog.jamisbuck.org/"
    end

 

This wasn’t too hard, was it? We have just extracted all the blogs URLs from planetrubyonrails.com! To observe the result, all we need is to run this snippet:

planet_ror_com_data.to_hash.each{|h| puts h[:link]}

The result is:

http://weblog.jamisbuck.org/
http://www.therailsway.com/
http://weblog.rubyonrails.com/
http://blogs.relevancellc.com/
http://www.anarchogeek.com/
http://www.bencurtis.com/
http://slash7.com/
http://blog.lathi.net/
http://convergentarts.com/
http://blog.innerewut.de/
http://codefluency.com/rails-views
http://www.busyashell.com/blog/
http://curthibbs.wordpress.com/
http://blog.bleything.net/
http://www.loudthinking.com/
http://railstips.org/
http://null.in/
http://www.jvoorhis.com/
http://www.puneruby.com/blog
http://sitekreator.com/satishtalim/rubyblog.html
http://www.rubyinside.com/
http://www.chadfowler.com/index.cgi
http://dibya.wordpress.com/
http://rubymerchant.blogspot.com/index.html
http://www.rubyonrailsblog.com/
http://blog.caboo.se/
http://www.ryandaigle.com/
http://vinsol.com/
http://jroller.com/page/obie
http://www.infoq.com/
http://drnicwilliams.com/
http://www.danwebb.net/
http://www.lukeredpath.co.uk/
http://blog.testingrails.com/
http://blog.vixiom.com/
http://robertrevans.com/
http://redhanded.hobix.com/
http://benmyles.com/
http://weblog.techno-weenie.net/
http://www.clarkware.com/cgi/blosxom
http://mir.aculo.us/
http://www.oreillynet.com/ruby/blog/
http://www.robbyonrails.com/
http://blog.grayproductions.net/
http://www.rubyquiz.com/
http://www.codyfauser.com/
http://railsexpress.de/blog/
http://www.softiesonrails.com/
http://blog.ericgoodwin.com/
http://iamrice.org/
http://blog.hasmanythrough.com/
http://david.goodlad.ca/
http://nubyonrails.topfunky.com/
http://onrails.org/
http://www.railtie.net/
http://brainspl.at/
http://podcast.rubyonrails.org/
http://blog.leetsoft.com/
http://errtheblog.com/
http://jystewart.net/process
http://www.pluginaweek.org/
http://mephistoblog.com/
http://encytemedia.com/
http://evil.che.lu/
http://technomancy.us/
http://poocs.net/
http://www.opensoul.org/
http://www.mathewabonyi.com/
http://www.railslivecd.org/
http://blog.methodmissing.com/
http://sporkmonger.com/breakpoint_client
http://typo.onxen.info/
http://blog.inquirylabs.com/
http://rashkovskii.com/
http://www.infused.org/
http://interblah.net/
http://streamlinedframework.com/
http://toolmantim.com/
http://webonrails.wordpress.com/
http://www.sapphiresteel.com/
http://eigenclass.org/hiki.rb
http://www.pjhyett.com/
http://jonathan.tron.name/
http://amazing-development.com/
http://merubyyoujane.com/
http://www.fallenrogue.com/
http://troubleseeker.com/
http://blog.nicksieger.com/
http://blog.methodmissing.com/
http://schf.uc.org/
http://www.brianketelsen.com/
http://www.simplisticcomplexity.com/
http://fluctisonous.com/
http://www.pinupgeek.com/
http://web2withrubyonrails.gauldong.net/
http://www.koziarski.net/
http://www.notsostupid.com/
http://www.shanesbrain.net/
http://blog.evanweaver.com/
http://www.zerosum.org/devblog
http://blog.zenspider.com/
http://townx.org/taxonomy/term/5/0
http://www.fromdelhi.com/
http://myles.eftos.id.au/blog
http://www.jeremyhubert.com/
http://www.jason-palmer.com/
http://seanicus.blogspot.com/
http://ajaxonrails.wordpress.com/
nil
http://www.matthewbass.com/blog
http://rails.co.za/
http://www.shifteleven.com/
http://peepcode.com/
http://blog.wolfman.com/
http://blog.dannyburkes.com/
http://jayfields.blogspot.com/
http://www.freeonrails.com/
http://techcheatsheets.com/tag/ruby%20or%20rails
http://rails-engines.org/rss/news/
http://www.railsenvy.com/
http://www.eribium.org/
http://hobocentral.net/blog
http://maintainable.com/articles
http://railspikes.com/
http://radiantcms.org/
http://hackety.org/
http://adam.blogs.bitscribe.net/
http://www.rubyfleebie.com/
http://www.stephenbartholomew.co.uk/
http://izumi.plan99.net/blog
http://blog.davidchelimsky.net

Looks good so far (although there is a nil value – we will deal with that later).

Let’s move on to http://planet.caboo.se/ which is just slightly harder to scrape:

    planet_caboose_data = Scrubyt::Extractor.define do
      fetch("http://planet.caboo.se/")

      link_row do
        link "al3x/@href"
      end
    end

The situation changed a bit: We need to match the row containing the blog address and feed address first, then scrape the “href” attribute of the blog URL link. Note how is this done – by appending “/@href” to the example string.

The next site is http://rubycorner.com/. The new thing here compared to the first two scrapers is that the blog URLs can be found on different pages – ergo we need to crawl to all of those pages. Fortunately this is no problem for scRUBYt!:

    rubycorner_data = Scrubyt::Extractor.define do
      fetch 'http://rubycorner.com/blogs/lang/en'

      link "Atlantic Dominion Solutions/@href"
      next_page ">"
    end

next_page is a special pattern which instructs scRUBYt! to crawl to next pages (the example “>” is used to identify the next page link).

Last but not least, here is the scraping code for http://www.planetrubyonrails.org/

      fetch "http://www.planetrubyonrails.org/"

      link_container "div[Feeds]" do
        link "a work on process/@href", :generalize => true
      end
    end

The link_container pattern instructs scRUBYt! to get a div containing the text “Feeds”, so that we scrape the links only inside the appropriate div (otherwise we would have some false positives). The :generalize => true option is used to match all the links, not just the first one.

I don’t have too much to say about the data cleaning part – if you are interested, you can download the code used for generating this tutorial and check it out there.

Scraping alexa was great fun – mainly because they don’t want to be scraped! However, if they would like to stop a halfway serious script junkie, they will have to do better than this. Here is the alexa extractor:

  def scrape(site)
    @hidden = open("http://client.alexa.com/common/css/scramble.css").read.scan(/^.(.+) /).flatten unless @hidden
    alexa_data = Scrubyt:: Extractor.define do
        fetch "http://www.alexa.com/data/details/traffic_details?url=#{site}"

        td "td[Traffic Rank for]" do
          span '/span[3]' do
            html :type => :html_subtree
          end
        end
    end
    data = alexa_data.to_hash[0][:html]
    data ? descramble(data) : nil
  end

  def descramble(mess)
    data = mess.gsub!(//,”).split(//)
    data = data.reject{|d| d==”" || (@hidden.include? d.scan(/”(.+?)”/).flatten[0])}
    data.map!{|d| d.sub(/”.+”>/,”) }
    data.join(”)
  end

If the above code does not make too much sense to you, don’t worry – I will explain it in a follow-up post. What really matters is that it is possible (and relatively easy) to scrape alexa with scRUBYt! and Ruby.

Here is the extractor I have used to scrape technorati:

  def scrape(site)
    techno_data = Scrubyt::Extractor.define do
      fetch "http://www.technorati.com/blogs/#{site}?reactions"
      rank "/html/body/div/div/div/div/div/div" do
        rank_number /Rank: (.+)$/
      end
    end
    techno_data.to_hash.reject{|h| h.empty?}[0][:rank_number]
  end

Nothing special here – what you did not see yet in the other extractors is the use of a regular expression pattern (rank_number), which gets the number out of the corresponding element and leaves the trash behind.

The only manual step I had to make in this whole process was to tweak the alexa results a bit – because according to alexa.com, “Alexa’s traffic rankings are for top level domains only (e.g. domain.com). We do not provide separate rankings for subpages within a domain (e.g. www.domain.com/subpage.html) or subdomains (e.g. subdomain.domain.com)“. This in practice meant that I have checked all blogger.com, wordpress.org, jroller.com and similar domains whether they concrete pages are really that high ranked, or just their top-level domain is. This blog also made it to the top 30, but I had to throw it away because about half of the traffic goes to the scRUBYt! forum, and the remaining visits were not enough to stay inside the top 30.

If you are still with me, I guess you had enough of scraping, screwing, cleaning and assembling by now – and your ordeal is over! Here are the results:

 

Ruby/Rails blog roundup based on alexa.com traffic values

1	http://redhanded.hobix.com	(59,519)
2	http://www.rubyinside.com	(59,729)
3	http://hivelogic.com	(73,585)
4	http://www.loudthinking.com	(77,521)
5	http://mephistoblog.com	(81,383)
6	http://weblog.techno-weenie.net	(93,041)
7	http://slash7.com	(98,732)
8	http://nubyonrails.com	(99,955)
9	http://errtheblog.com	(105,525)
10	http://rubyonrailsblog.com	(117,842)
11	http://pjhyett.com	(118,985)
12	http://www.railsenvy.com	(123,414)
13	http://encytemedia.com	(127,451)
14	http://www.igvita.com/blog	(131,955)
15	http://blog.zenspider.com	(133,281)
16	http://juixe.com/techknow	(134,454)
17	http://peepcode.com	(136,202)
18	http://weblog.jamisbuck.org	(136,606)
19	http://project.ioni.st	(149,352)
20	http://railscasts.com	(154,733)
21	http://metaatem.net	(155,901)
22	http://www.danwebb.net	(162,936)
23	http://www.robbyonrails.com	(181,590)
24	http://www.urbanhonking.com/ideasfordozens	(184,096)
25	http://blog.codahale.com	(188,987)
26	http://drnicwilliams.com	(197,798)
27	http://topfunky.com	(199,064)
28	http://blog.innerewut.de	(200,308)
29	http://web2withrubyonrails.gauldong.net	(203,938)
30	http://brainspl.at	(209,069)

 

 

 

 

Ruby/Rails blog roundup based on technorati.com traffic values

1	http://www.loudthinking.com	(3,164)
2	http://metaatem.net	(5,173)
3	http://mephistoblog.com	(6,223)
4	http://hivelogic.com	(6,498)
5	http://www.rubyinside.com	(7,899)
6	http://errtheblog.com	(8,587)
7	http://nubyonrails.com	(10,277)
8	http://quotedprintable.com	(10,680)
9	http://slash7.com	(11,154)
10	http://redhanded.hobix.com	(11,154)
11	http://project.ioni.st	(11,957)
12	http://weblog.jamisbuck.org	(12,412)
13	http://blog.leetsoft.com	(13,270)
14	http://weblog.rubyonrails.com	(13,445)
15	http://www.danwebb.net	(16,844)
16	http://www.igvita.com/blog	(17,262)
17	http://www.chadfowler.com	(17,262)
18	http://blog.codahale.com	(17,601)
19	http://clarkware.com/cgi/blosxom	(22,954)
20	http://drnicwilliams.com	(23,098)
21	http://www.oreillynet.com/ruby/blog	(23,346)
22	http://peepcode.com	(24,393)
23	http://eigenclass.org	(24,393)
24	http://mir.aculo.us	(25,071)
25	http://on-ruby.blogspot.com	(26,808)
26	http://antoniocangiano.com	(29,929)
27	http://www.therailsway.com	(30,395)
28	http://www.softiesonrails.com	(31,790)
29	http://glu.ttono.us	(33,550)
30	http://www.ryandaigle.com	(34,998)

 

 

There were a few blogs which performed equally well on both lists – they were assembled into a top 10 list, which you can check out here.

I would really like to hear your opinion on this little experiment – whether you think it makes sense or it is completely off, how could it be improved in the future, what features could be added etc. If I’ll receive some positive feedback, I think I will work on the algorithm a bit more, and run it once in say every 3 months to see what’s happening around the Ruby/Rails blogosphere. Let me know what do you think!

 

Related Links

• The code used in the article
• The final result: Ruby/Rails blog top 10

 

scRUBYt! 0.3.0 released

Posted by admin

 

Thanks to thescRUBYt! forum, the team has received a *lot* of feedback – we have tried to incorporate the most features requested by the most people, also fixing a few annoying bugs. Well, I guess no one is interested in this introductory babbling, so here you go: the CHANGELOG for 0.3.0:

[NEW] complete rewrite of the output system, creating a solid
           foundation for more robust output functions
           (credit: Neelance)
[NEW] logging - no annoying puts messages anymore!
           (credit: Tim Fletcher)
[NEW] can index an example - e.g.
           link “more[5]”‘
           semantics: give me the 6th element with the text “more”
[NEW] can use XPath checking an attribute value, like
            “//div[@id=’content’]”
[NEW] default values for missing elements (first version was
            done in 0.2.8 but it did not work for all cases)
[NEW] possibility to click button with it’s text (instead of it’s index)
           (credit: Nick Merwin)
[NEW] clicking radio buttons
[NEW] can click on image buttons (by specifying the name of the
           button)
[NEW] possibility to extract an URL with one step, like so:
          link “The Difference/@href”
           i.e. give me the href attribute of the element matched by the
           example ‘The Difference’
[NEW] new way to match an element of the page:
           content “div[The Difference]”
           means ‘return the div which contains the string “The Difference”‘.
           This is useful if the XPath of the element is non-constant across
           the same site (e.g.sometimes a banner or add is added, sometimes
           not etc.)
[NEW] Clicking image maps; At the moment this is achieved by specifying
           an index, like
           click_image_map 3
          which means click the 4th link in the image map
[FIX] Replacing 240 ( ) with space in the preprocessing phase
         automatically
[FIX] Fixed: correctly downloading image if the src attribute had a leading
         space, as in