browscap.rb

require 'inifile'

class Browscap
  def initialize(filename = 'browscap.ini')
    @@user_agent_properties ||= {}
    @@user_agent_regexps ||= {}
    @@match_cache ||= {}
    
    if @@user_agent_properties.empty? || @@user_agent_regexps.empty?
      ini = IniFile.load(filename)
      
      # Remote meta sections
      ini.delete_section '*'
      ini.delete_section 'GJK_Browscap_Version'
      
      # Create a list of non-parent sections
  		child_sections = ini.sections.dup
  		ini.sections.each do |section|
  			child_sections.delete ini[section]["Parent"]
  		end
  		
  		# Populate user_agent_properties and user_agent_regexps
  		child_sections.each do |section|
  		  properties = _get_browser_props(ini, section)
  		  
        browser = Browser.new
        browser.browser = properties['Browser']
        browser.version = properties['Version']
        browser.major_ver = properties['MajorVer'].to_i
        browser.minor_ver = properties['MinorVer'].to_i
        browser.platform = properties['Platform']
        browser.alpha = properties['Alpha'].downcase == 'true'
        browser.beta = properties['Beta'].downcase == 'true'
        browser.win16 = properties['Win16'].downcase == 'true'
        browser.win32 = properties['Win32'].downcase == 'true'
        browser.win64 = properties['Win64'].downcase == 'true'
        browser.frames = properties['Frames'].downcase == 'true'
        browser.iframes = properties['IFrames'].downcase == 'true'
        browser.tables = properties['Tables'].downcase == 'true'
        browser.cookies = properties['Cookies'].downcase == 'true'
        browser.background_sounds = properties['BackgroundSounds'].downcase == 'true'
        browser.javascript = properties['JavaScript'].downcase == 'true'
        browser.vbscript = properties['VBScript'].downcase == 'true'
        browser.java_applets = properties['JavaApplets'].downcase == 'true'
        browser.activex_controls = properties['ActiveXControls'].downcase == 'true'
        browser.is_banned = properties['isBanned'].downcase == 'true'
        browser.is_mobile_device = properties['isMobileDevice'].downcase == 'true'
        browser.is_syndication_reader = properties['isSyndicationReader'].downcase == 'true'
        browser.crawler = properties['Crawler'].downcase == 'true'
        browser.css_version = properties['CssVersion'].to_i
        browser.supports_css = properties['supportsCSS'].downcase == 'true'
        browser.aol_version = properties['aolVersion'].to_i
        browser.aol = properties['AOL'].downcase == 'true'
  		  
  		  @@user_agent_properties[section] = browser
  		  
  		  # Convert .ini file regexp syntax into ruby regexp syntax
  			regexp = section.dup
  			regexp.gsub! /([\^\$\(\)\[\]\.\-])/, "\\\\\\1"
  			regexp.gsub! "?", "."
  			regexp.gsub! "*", ".*?"
  			
  			@@user_agent_regexps[section] = Regexp.new("^%s$" % regexp)
  		end
    end
  end
  
  # Looks up the given user agent string and returns a dictionary containing information on this browser or bot.
  def query(user_agent)
    section = _match(user_agent)
    @@user_agent_properties[section]
  end
  
  def _match(user_agent)
    return @@match_cache[user_agent] if @@match_cache[user_agent]

		matching_section = ''
		
		@@user_agent_regexps.each do |section, regexp|
		  # Find the longest regexp that matches the given user_agent_string. The length check is needed since multiple reg-exps may match the user_agent_string.
		  if regexp.match(user_agent) && section.length > matching_section.length
		    matching_section = section
		  end
		end
		
		@@match_cache[user_agent] = matching_section
		matching_section
  end
  
	# Recursively traverses the properties tree (based on 'parent' attribute of each section) and 
	# returns a dictionary of all browser properties for the given section name. The properties lower 
	# in the tree override those higher in the tree.
  def _get_browser_props(ini, section)
    data = {}
    
    if parent = ini[section]["Parent"]
      data.merge! _get_browser_props(ini, parent)
    end
    
    data.merge! ini[section]
    data
  end
end

class Browser
  attr_accessor :browser, :version, :major_ver, :minor_ver, :platform, :alpha, :beta, :win16, :win32, :win64,
                :frames, :iframes, :tables, :cookies, :background_sounds, :javascript, :vbscript, :java_applets, :activex_controls,
                :is_banned, :is_mobile_device, :is_syndication_reader, :crawler, :css_version, :supports_css, :aol_version, :aol
end