Class: SeoCache::Middleware

Inherits:
Object
  • Object
show all
Defined in:
lib/seo_cache/middleware.rb

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ Middleware

Returns a new instance of Middleware.



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# File 'lib/seo_cache/middleware.rb', line 8

def initialize(app, options = {})
  @options              = options
  @extensions_to_ignore = SeoCache.extensions_to_ignore
  @crawler_user_agents  = SeoCache.crawler_user_agents

  @app = app

  @page_caching = PageCaching.new
end

Instance Method Details

#after_render(env, response, status = 200) ⇒ Object 



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# File 'lib/seo_cache/middleware.rb', line 207

def after_render(env, response, status = 200)
  return unless response && SeoCache.cache_only_status.include?(status.to_i)

  if SeoCache.log_missed_cache
    env_request = Rack::Request.new(env)
    SeoCache.log("missed cache : #{env_request.path} (User agent: #{env_request.user_agent})")
  end

  @page_caching.cache(response, Rack::Request.new(env).path)
end

#before_render(env) ⇒ Object 



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# File 'lib/seo_cache/middleware.rb', line 179

def before_render(env)
  # return nil unless @options[:before_render]
  # cached_render = @options[:before_render].call(env)

  cached_render = @page_caching.get(Rack::Request.new(env).path)

  return nil unless cached_render

  if cached_render.is_a?(String)
    Rack::Response.new(cached_render, 200, 'Content-Type' => 'text/html; charset=utf-8')
  elsif cached_render.is_a?(Rack::Response)
    cached_render
  end
end

#build_api_url(env) ⇒ Object 



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# File 'lib/seo_cache/middleware.rb', line 147

def build_api_url(env)
  new_env = env
  if env['CF-VISITOR']
    match = /"scheme":"(http|https)"/.match(env['CF-VISITOR'])
    (new_env['HTTPS'] = true) && (new_env['rack.url_scheme'] = 'https') && (new_env['SERVER_PORT'] = 443) if match && match[1] == 'https'
    (new_env['HTTPS'] = false) && (new_env['rack.url_scheme'] = 'http') && (new_env['SERVER_PORT'] = 80) if match && match[1] == 'http'
  end

  if env['X-FORWARDED-PROTO']
    (new_env['HTTPS'] = true) && (new_env['rack.url_scheme'] = 'https') && (new_env['SERVER_PORT'] = 443) if env['X-FORWARDED-PROTO'].split(',')[0] == 'https'
    (new_env['HTTPS'] = false) && (new_env['rack.url_scheme'] = 'http') && (new_env['SERVER_PORT'] = 80) if env['X-FORWARDED-PROTO'].split(',')[0] == 'http'
  end

  if SeoCache.protocol.present?
    (new_env['HTTPS'] = true) && (new_env['rack.url_scheme'] = 'https') && (new_env['SERVER_PORT'] = 443) if @options[:protocol] == 'https'
    (new_env['HTTPS'] = false) && (new_env['rack.url_scheme'] = 'http') && (new_env['SERVER_PORT'] = 80) if @options[:protocol] == 'http'
  end

  url           = Rack::Request.new(new_env).url
  prerender_url = SeoCache.prerender_service_url
  forward_slash = prerender_url[-1, 1] == '/' ? '' : '/'
  "#{prerender_url}#{forward_slash}#{url}"
end

#build_response_from_prerender(prerender_response) ⇒ Object 



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# File 'lib/seo_cache/middleware.rb', line 171

def build_response_from_prerender(prerender_response)
  response = Rack::Response.new(prerender_response.body, prerender_response.code, prerender_response.header)

  # @options[:build_rack_response_from_prerender]&.call(response, prerendered_response)

  return response
end

#call(env) ⇒ Object 



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# File 'lib/seo_cache/middleware.rb', line 18

def call(env)
  if prerender_page?(env)
    cached_response = before_render(env)

    return cached_response.finish if cached_response.present?

    if SeoCache.log_missed_cache
      env_request = Rack::Request.new(env)
      SeoCache.log("missed cache : #{env_request.path} (User agent: #{env_request.user_agent})")
    end

    if SeoCache.prerender_service_url.present?
      prerender_response = prerender_service(env)
      if prerender_response
        response = build_response_from_prerender(prerender_response.body)
        after_render(env, prerender_response)
        return response.finish
      end
    else
      Thread.new do
        prerender_data = page_render(env)
        # Extract status from render page or return 404
        status = prerender_data&.scan(/<!--status:(\d+)-->/)&.last&.first
        after_render(env, prerender_data, status || 200)
      end
    end
  elsif prerender_params?(env)
    env['seo_mode'] = true
    # Add status to render page because Selenium doesn't return http headers or status...
    status, headers, response = @app.call(env)
    status_code               = "<!--status:#{status}-->"
    # Cannot add at the top of file, Chrome removes leading comments...
    begin
      body_code = response.body.sub(/<head( ?)(.*?)>/i, "<head\\1\\2>#{status_code}")
      return [status, headers, [body_code]]
    rescue
      return [status, headers, [nil]]
    end
  end

  return @app.call(env)
end

#page_render(env) ⇒ Object 



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# File 'lib/seo_cache/middleware.rb', line 194

def page_render(env)
  # Add key parameter to url
  request = Rack::Request.new(env)
  url     = if request.query_string.present? || request.url.include?('?')
              request.url + '&'
            else
              request.url + '?'
            end
  url     += "#{SeoCache.prerender_url_param}=true"

  return PageRender.new.get(url)
end

#prerender_page?(env) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/seo_cache/middleware.rb', line 72

def prerender_page?(env)
  user_agent                   = env['HTTP_USER_AGENT']
  buffer_agent                 = env['HTTP_X_BUFFERBOT']
  is_requesting_prerender_page = false

  return false unless user_agent

  return false if env['REQUEST_METHOD'] != 'GET'

  request      = Rack::Request.new(env)
  query_params = Rack::Utils.parse_query(request.query_string)

  # Check if user connected
  return false if !SeoCache.cache_with_user_connected && (env['warden'].respond_to?(:user) && env['warden'].user.present?)

  # If it is the generated page...don't prerender
  return false if query_params.has_key?(SeoCache.prerender_url_param)

  # if it is a bot and host doesn't contain these domains...don't prerender
  return false if SeoCache.whitelist_hosts.present? && SeoCache.whitelist_hosts.none? { |host| request.host.include?(host) }

  # if it is a bot and urls contain these params...don't prerender
  return false if SeoCache.blacklist_params.present? && SeoCache.blacklist_params.any? { |param| query_params.has_key?(param) }

  # if it is a bot and is requesting a resource...don't prerender
  return false if @extensions_to_ignore.any? { |extension| request.fullpath.include? extension }

  # if it is a bot and not requesting a resource and is not whitelisted...don't prerender
  return false if SeoCache.whitelist_urls.present? && SeoCache.whitelist_urls.all? { |whitelisted| !Regexp.new(whitelisted).match(request.fullpath) }

  # if it is a bot and not requesting a resource and is blacklisted(url or referer)...don't prerender
  blacklisted_url = SeoCache.blacklist_urls.present? && SeoCache.blacklist_urls.any? do |blacklisted|
    regex = Regexp.new(blacklisted)

    blacklisted_url     = regex.match(request.fullpath)
    blacklisted_referer = request.referer ? regex.match(request.referer) : false

    blacklisted_url || blacklisted_referer
  end
  return false if blacklisted_url

  is_requesting_prerender_page = true if Rack::Utils.parse_query(request.query_string).has_key?('_escaped_fragment_') || Rack::Utils.parse_query(request.query_string).has_key?(SeoCache.force_cache_url_param)

  # if it is a bot...show prerendered page
  is_requesting_prerender_page = true if @crawler_user_agents.any? { |crawler_user_agent| user_agent.downcase.include?(crawler_user_agent.downcase) }

  # if it is BufferBot...show prerendered page
  is_requesting_prerender_page = true if buffer_agent

  SeoCache.log('force cache : ' + request.path) if Rack::Utils.parse_query(request.query_string).has_key?(SeoCache.force_cache_url_param) && SeoCache.log_missed_cache

  return is_requesting_prerender_page
end

#prerender_params?(env) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/seo_cache/middleware.rb', line 61

def prerender_params?(env)
  return false if env['REQUEST_METHOD'] != 'GET'

  request      = Rack::Request.new(env)
  query_params = Rack::Utils.parse_query(request.query_string)

  return false if @extensions_to_ignore.any? { |extension| request.fullpath.include? extension }

  return true if query_params.has_key?(SeoCache.prerender_url_param) || query_params.has_key?(SeoCache.force_cache_url_param)
end

#prerender_service(env) ⇒ Object 



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# File 'lib/seo_cache/middleware.rb', line 126

def prerender_service(env)
  url          = URI.parse(build_api_url(env))
  headers      = {
    'User-Agent'      => env['HTTP_USER_AGENT'],
    'Accept-Encoding' => 'gzip'
  }
  req          = Net::HTTP::Get.new(url.request_uri, headers)
  http         = Net::HTTP.new(url.host, url.port)
  http.use_ssl = true if url.scheme == 'https'
  response     = http.request(req)
  if response['Content-Encoding'] == 'gzip'
    response.body              = ActiveSupport::Gzip.decompress(response.body)
    response['Content-Length'] = response.body.length
    response.delete('Content-Encoding')
  end

  return response
rescue StandardError => error
  SeoCache.log_error(error.message)
end