Sitemap Generator

sitemap_generator.rb

class SitemapGenerator
  # For Rails 3.*, replace with include Rails.application.routes.url_helper
  include ActionController::UrlWriter 
  
  def initialize model_name, options = {}
    @host = options.delete(:host) || default_url_options[:host]
    @model_name = model_name
    @file = options.delete(:file) || model_name.to_s.pluralize
    @changefreq = options.delete(:changefreq) || 'daily'
    @lastmod = options.delete(:lastmod_method) || :updated_at
    @priority = options.delete(:priority) || '0.5'
    @sitemap_path = File.join(RAILS_ROOT,"public","#{@file}.xml")
    @compress = options.delete(:compress) || false
  end
  
  def generate
    File.open(@sitemap_path,"w") do |f|
      f.write(%[<?xml version="1.0" encoding="UTF-8"?>\n])
      f.write(%[<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n])
      @model_name.camelize.constantize.all.each do |item|
        f.write %[<url><loc><![CDATA[#{send(:"#{@model_name}_url",item, :host => @host)}]]></loc><lastmod>#{item.send(@lastmod).utc.strftime("%Y-%m-%dT%H:%M:%S+00:00")}</lastmod><changefreq>#{@changefreq}</changefreq><priority>#{@priority}</priority></url>\n]
      end
      f.write(%[</urlset>])
    end
    
    `gzip -f #{@sitemap_path}` if @compress
  end
  
  class << self
    def generate model_name, options = {}
      generator = new(model_name, options)
      generator.generate
    end
  end
end