main.rb

require 'sinatra'
require 'sinatra/reloader'
require 'metainspector'
require 'open-uri'

set :show_exceptions, :after_handler

helpers do
  def show_if_present(title, value)
    "<h3>#{title}</h3><p>#{value}</p>" unless value.nil? || value.length == 0
  end

  def link_if_present(title, value)
    show_if_present(title, "<a href='#{value}'>#{value}</a>") unless value.nil? || value.length == 0
  end

  def paint_images(images)
    images.map { |image| "<a href='#{image}'><img src='#{image}' height='75' hspace='5' vspace='5' style='border: 1px solid #ddd;'/></a>" }.join
  end

  def links_to_li(links)
    links.map { |link| "<li><a href='#{link}'>#{link}</a></li>" }.join("\n")
  end
end

get '/' do
  erb :home
end

get '/scrape' do
  if params[:url]
    @page = MetaInspector.new(params[:url],
                              :connection_timeout => 5, :read_timeout => 5,
                              :headers => { 'User-Agent' => user_agent, 'Accept-Encoding' => 'identity' },
                              :faraday_options => { :ssl => { :verify => false } },
                              :html_content_only => true)
    erb :scrape
  else
    redirect "/"
  end
end

error MetaInspector::Error do
  @exception_title = env['sinatra.error'].class.to_s
  @exception_msg   = env['sinatra.error'].message
  erb :error
end

private

def user_agent
  "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.111 Safari/537.36"
end