Class: Scraper

Inherits:
Object
  • Object
show all
Defined in:
lib/sp500_analyzer/scraper.rb

Constant Summary collapse

URL = 
"http://www.multpl.com/s-p-500-historical-prices/table/by-month"

Class Method Summary collapse

Class Method Details

.array_to_datapoints ⇒ Object 



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# File 'lib/sp500_analyzer/scraper.rb', line 43

def self.array_to_datapoints
  # new_data_points = []
  webpage_to_html.reverse.each_with_index do |row, index|
    price = row.css("td.right").text.gsub(",","").to_f
    date = row.css("td.left").text
    # binding.pry
    if price > 0.0 && !date.empty?
      dp = DataPoint.new
      dp.id = index
      dp.date = string_to_date(date)
      dp.price = price
      if DataPoint.all[index-1].price > 0.0
        dp.monthly_change = price - DataPoint.all[index-1].price
      end
      if !DataPoint.all[index-12].nil? && DataPoint.all[index-12].price > 0.0
        dp.yearly_change = price - DataPoint.all[index-12].price
      end
      # new_data_points << dp
    end
  end
  nil
end

.string_to_date(string) ⇒ Object 



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# File 'lib/sp500_analyzer/scraper.rb', line 11

def self.string_to_date(string)
  # month = 0
  data_array = string.split(/,|\s/).select{ |s| !s.strip.empty? }
  case data_array[0]
  when "Jan"
    month = 1
  when "Feb"
    month = 2
  when "Mar"
    month = 3
  when "Apr"
    month = 4
  when "May"
    month = 5
  when "Jun"
    month = 6
  when "Jul"
    month = 7
  when "Aug"
    month = 8
  when "Sep"
    month = 9
  when "Oct"
    month = 10
  when "Nov"
    month = 11
  when "Dec"
    month = 12
  end
  Date.new(data_array[2].to_i, month, data_array[1].to_i)
end

.webpage_to_html ⇒ Object 



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# File 'lib/sp500_analyzer/scraper.rb', line 7

def self.webpage_to_html
  Nokogiri::HTML(open(URL)).css("table#datatable tr")
end