Question

I’m trying to figure out why I am getting this error when I run this part of my code: in ‘clean_up_keywords’: undefined method for ‘gsub’ for nil:NilClass (NoMethodError)
However, when I run the full code with Sinatra, I get no errors.

Partial code:

def clean_up_keywords(str)
  str.gsub("\n", ",").delete("\r").split(',')
end

def clean_up_list(arr)
  arr.reject(&:empty?).each(&:lstrip!)
end

def make_strings_url_friendly(arr)
  arr.each do |e|
    e.gsub!(" ", "+")
  end
end

def make_urls(arr)
  arr.map {|e| "http://www.google.com/search?num=100&q=" + e}
end


  params = Hash.new#test
  params["keyword"] = "red\r\nblue\r\ngreen"
  params["url"] = "http://url.com"
  dirty_list = clean_up_keywords(params[:keyword])
  clean_list = clean_up_list(dirty_list)
  url_ready_list = make_strings_url_friendly(clean_list)
  url_list = make_urls(url_ready_list)

Full code for use in Sinatra:

require 'sinatra'
require 'rspec'
require 'nokogiri'
require 'open-uri'

get '/serp_checker' do
  "<form action='/ranked' method='post'>
  <label for='keyword'>Keyword</label>
  <textarea name='keyword' id='keyword' type='text' /></textarea>
  <label for='url'>URL</label>
  <input name='url' id='url' type='text' />
  <input type='submit' value='Go!' />
  </form>"
end

def clean_up_keywords(str)
  str.gsub("\n", ",").delete("\r").split(',')
end

def clean_up_list(arr)
  arr.reject(&:empty?).each(&:lstrip!)
end

def make_strings_url_friendly(arr)
  arr.each do |e|
    e.gsub!(" ", "+")
  end
end

def make_urls(arr)
  arr.map {|e| "http://www.google.com/search?num=100&q=" + e}
end

post '/ranked' do
  #params = Hash.new#test
  #params["keyword"] = "red\r\nblue\r\ngreen"#test
  #params["url"] = "http://url.com"#test
  #serp = Nokogiri::HTML(open("http://www.google.com/search?num=100&q=house"))
  #puts serp.to_s
  dirty_list = clean_up_keywords(params[:keyword])
  clean_list = clean_up_list(dirty_list)
  url_ready_list = make_strings_url_friendly(clean_list)
  url_list = make_urls(url_ready_list)
end

Answer 1

You define params["keyword"]but access params[:keyword], so it returns nil, because it could not be found – symbols and strings are different objects as keys.

A workaround is to use something like http://as.rubyonrails.org/classes/HashWithIndifferentAccess.html