Easy method of finding and determining corequisites, prerequisites, restrictions, and any other minor detail shown on the Notre Dame description page. If any of these details are returned as nil, then it does not have that specific attribute.

notre_dame_class_detail.rb

require 'nokogiri'
require 'faraday'

@term = "201420"
@crn = "14433"
@crn = "21129"
@crn = "22091"

@conn = Faraday.new(:url => 'https://class-search.nd.edu/reg/srch/ClassSearchServlet') do |faraday|
  faraday.request :url_encoded
  faraday.response :logger
  faraday.adapter Faraday.default_adapter
end

puts "Beginning the script."

response = @conn.get '', {:CRN => @crn, :TERM => @term}
content = response.body.strip

document = Nokogiri::HTML(content)

course_restriction_node = document.at('span:contains("Cannot Have Taken")')
#course_restriction_node = document.search "[text()*='Cannot Have Taken:']"
puts course_restriction_node.content.strip
#puts course_restriction_node.parent
#puts course_restriction_node.parent.next_element
course_restriction_text = course_restriction_node.next_sibling.next_sibling.content.strip
puts course_restriction_text

#fetch_restrictions(document)

def fetch_course_details
  response = @conn.get '', {:CRN => @crn, :TERM => @term}
  content = response.body.strip

  document = Nokogiri::HTML(content)

  fetch_course_description(document)
  fetch_course_restrictions(document)
  fetch_corequisites(document)
  fetch_prerequisites(document)
end

def fetch_course_description(doc)
  description_node = doc.at('span:contains("Course Description")')
  desc_text = description_node.next_sibling.next_sibling.content.strip
  puts desc_text
end

def fetch_course_restrictions(doc)
  restriction_node = doc.at('span:contains("Cannot Have Taken")')
  if restriction_node
    restriction_text = restriction_node.next_sibling.next_sibling.content.strip
    restriction_text.strip.split.join('').gsub(/\s+/, '')
    restriction_array = restriction_text.split(",")
    #puts restriction_array.length
    restriction_array.each do |restriction|
      course_num = restriction.gsub(/\s+/, '').gsub(/\W/, '').strip
      puts course_num
    end
  end
  # For restriction text, it should split on the comma because that's the delimiter for multiple values.
  # After splitting or attempting to split on the comma, then the code should next call split
  # on the space between the Dept & Course or remove the space to join the two parts together,
  # so then the database/model can query for this object and create something new.
end

def fetch_corequisites(doc)
  corequisites_node = doc.at('span:contains("Corequisites")')
  if corequisites_node
    corequisites_text = corequisites_node.next_sibling.next_sibling.content.strip
    corequisites_array = corequisites_text.split(",")
    corequisites_array.each do |node|
      node_text = node.gsub!(/\s+/, '').strip
      puts node_text.length
      puts node_text
    end
  end
end

def fetch_prerequisites(doc)
  prerequisites_node = doc.at('span:contains("Prerequisites")')
  if prerequisites_node
    prereq_text = prerequisites_node.next_element.next_sibling.content.strip
    if prereq_text.include? "or"
      join_word = "or"
    elsif prereq_text.include? "and"
      join_word = "and"
    else
      join_word = ''
    end
    prereq_array = prereq_text.split(",") || prereq_text.split("or") || prereq_text.split("and")
    prereq_array.each do |node|
      node_text = node.gsub!(/\s+/, '').gsub!(/\W/, '').strip
    end
  end
end

fetch_course_details

todo.md

• Get majors required
• Get campus required?
• Get degree required