Question

I’ve got a module that does webscraping. I use this method a number of times, since it captures all the data on the webpage.

def page_as_xml(uri)
  @page_as_xml ||= Nokogiri::HTML(open(uri))
end

Since I’ll use the above method a handful of times for each page, it makes sense to keep it in an instance variable. However, how do I “empty out” the instance variable after I’m done?

All the webcsraping ends up in a hash (see below). If I don’t “empty out” the instance variable, then the same page_as_xml data will get used for each page.

    :page1 =>
      {
        :url => @page1,
        :title => download_title(@page1),
        :meta_tags => download_robots_tags(@page1) 
      },
    :page2 =>
      {
        :url => @page2,
        :title => download_title(@page2),
        :meta_tags => download_robots_tags(@page2) 
      },
    :page3 =>
      {
        :url => @page3,
        :title => download_title(@page3),
        :meta_tags => download_robots_tags(@page3) 
      },

Answer 1

How about make it a hash:

@pages_as_xml[uri] ||= Nokogiri::HTML(open(uri))

Now you don’t have to worry about emptying it (unless memory is an issue).
I don’t really understand why you need to call it more than once though. Also why do you call it page_as_xml if it is html?