Import without errors - when you ask for nested things.

gistfile1.txt

# Actually Id also move all the rubbish out of the middle and make variables so it hurts your brain less.
# call the variables what you like, but see how it's like, sigh of releif. 
# Make your brain pass the least amount of crap as possible.
# Encapsulation lets you hide ugly things inside nice little packages :)

require 'rubygems'
require 'nokogiri'
require 'open-uri'

domain_url = "http://prod3.agileticketing.net/websales/pages/"
listings = ".Item , .ViewLink"
title_field = ".Name"
date_field = "Date"
time_field = ".Time , span"
url_field = ".ViewLink"

url = "http://prod3.agileticketing.net/websales/pages/list.aspx?epguid=5e3ea987-8f29-408f-ad74-5c32388b1f83&"
doc = Nokogiri::HTML(open(url))
doc.css(listings).each do |event|
	if event 
		if event.at_css(title_field)
  		title = (event.at_css(title_field).text || 'title unknown') 
  	end
  	if event.at_css(time_field)
  		start_time = (event.at_css(time_field).text || nil) 
  	end
  	if event.at_css(url_field)
  		url = domain_url + event.at_css(url_field)[:href] if event.at_css(url_field)
  	end
  end
  puts "#{title} - #{start_time} - #{url}"
end

importer.rb

require 'rubygems'
require 'nokogiri'
require 'open-uri'

url = "http://prod3.agileticketing.net/websales/pages/list.aspx?epguid=5e3ea987-8f29-408f-ad74-5c32388b1f83&"
doc = Nokogiri::HTML(open(url))
doc.css(".Item , .ViewLink").each do |event|
	if event 
		if event.at_css(".Name")
  		title = (event.at_css(".Name").text || 'title unknown') 
  	end
  	if event.at_css(".Time , span")
  		start_time = (event.at_css(".Time , span").text || nil) 
  	end
  	if event.at_css(".ViewLink")
  		url = "http://prod3.agileticketing.net/websales/pages/" + event.at_css(".ViewLink")[:href] if event.at_css(".ViewLink")
  	end
  end
  puts "#{title} - #{start_time} - #{url}"
end

make_a_rake_file.rb

Event.new creating errors
The issue has to do with the ruby file loading up your fulls rails environment.
Now is the time to introduce rake (very briefly).
I suggest you read this short into to rake here: http://jasonseifer.com/2010/04/06/rake-tutorial
Watch this vid by the creator if you are interested: https://www.youtube.com/watch?v=AFPWDzHWjEY

Do this.

1. rename your file from .rb to .rake
2. Add this around your code
 
    # keep require statements up the top of the file.
    task :import_docfest => :environment do
      # All your current code goes in the middle, except the require statements which go above.
    end

From the command line you now type.

    $ rake import_docfest

The rake tool finds all the rake files and then finds a task matching your task name and runs it.
you can run this rake task from the root/base directory of your project, no need to mention the path anymore.

notes.rb

# When you want to query nested things.
# eg animal.fur.color # you can only ask for color if animal and animal.fur exist.

# So you need to use this sort of structure.
if animal
 if animal.fur
     # code here
     puts animal.fur.color
  end   
end

# This can be tidied up to be:

if animal && animal.fur
  puts animal.fur.color
end

# or even nicer using rubys if at the end trick:
  puts animal.fur.color if animal && animal.fur