Simple crawler API

crawler_api.rb

options = { :wait => 10 }

# one big set
result = Crawler.crawl("http://www.example.com", options)
result.image
result.style_sheets
result.scripts # => [<Crawler::Response::Script>]
...
result.errors

# per page
Crawler.crawl("http://www.example.com", options) do |page|
  page.images
  ...
  page.document # =>
end