How do I automate Nokogiri?

Question

While learning how to use Nokogiri in Ruby,I got this idea,what if I can automate these commands which I write in bash for Nokogiri? Is there any way or method which I can use to automate the call?

For example: As I was trying to grab some data from one site I wrote:

require 'rubygems'
require 'nokogiri'   
require 'open-uri'
PAGE_URL = "http://hackerstreet.in"
page = Nokogiri::HTML(open(PAGE_URL))

links = page.css("a")
puts links.length   
puts links[0].text   
puts links[0]["href"] 

And, to execute it, I have to enter this command at the command line:

$ ruby any.rb > any.html

What shall I do in order to run the same from a Web-App.

If anyone can help on this issue then that would be great.

Answer 1

Insert the code into a library of your rails app as a method. Usually the library is placed in lib/ folder from root of Rails app. Then call the defined method directly from a controller, the call :respond method to handle the request from a browser, and output result of the method work in a view. If the grab procedure take a lot of tike use asyncronous operations, for example with event-machine gem.

The simplest app is the following:

app/controllers/your_controller.rb

def index
   result = WebGrab.grab "http://hackerstreet.in"
   render text: result.inspect # just renders text, replace it as a call to render a view
end

lib/webgrab.rb

require 'nokogiri'   
require 'open-uri'

module WebGrab
   def self.grab uri
      page = Nokogiri::HTML( open uri )

      links = page.css("a")
      [ links.length, puts links[0].text, links[0]["href"] ]
   end
end