Stanley/chrome_frame.rb

## chrome_frame.rb
module Rack
  class ChromeFrame

    def initialize(app, options={})
      @app = app
      @options = options
    end

    def call(env)

      if env['HTTP_USER_AGENT'] =~ /MSIE/
        if env['HTTP_USER_AGENT'] =~ /chromeframe/
          status, headers, response = @app.call(env)
          new_body = insert_tag(build_response_body(response))
          new_headers = recalculate_body_length(headers, new_body)
          return [status, new_headers, new_body]
        elsif @options[:minimum].nil? or ie_version(env['HTTP_USER_AGENT']) < @options[:minimum]
          html = <<-HTML
            <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
            <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
              <head>
                <meta http-equiv="content-type" content="text/html;charset=UTF-8" />
                <title>You must install chromeframe in order to see this page!</title>
              </head>
              <body>
                <div id="cf-placeholder"></div>
                <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/chrome-frame/1/CFInstall.min.js"></script>
                <script>CFInstall.check({ node: "cf-placeholder" #{', destination: "' + @options[:destination] + '" ' if @options[:destination]}});</script>
              </body>
            </html>
          HTML
          return [200, {'Content-Type' =>  'text/html', 'Content-Length' => html.size.to_s}, Rack::Response.new([html])]
        end
      end
      @app.call(env)
    end

    def build_response_body(response)
      response_body = ""
      response.each { |part| response_body += part }
      response_body
    end

    def recalculate_body_length(headers, body)
      new_headers = headers
      new_headers["Content-Length"] = body.length.to_s
      new_headers
    end

    def insert_tag(body)
      head = <<-HEAD
        <meta http-equiv="X-UA-Compatible" content="chrome=1">
      HEAD

      body.gsub!('<head>', "<head>\n" + head )
      body
    end

    def ie_version(ua_string)
      ua_string.match(/MSIE (\S+)/)[1].to_f
    end
  end
end

## chrome_frame_spec.rb
require File.dirname(__FILE__) + '/helper'

describe "Rack::ChromeFrame" do

  before do
    @app = lambda { |env| [200, {'Content-Type' => 'text/html'}, simple_html] }
    @request = Rack::MockRequest.new(Rack::ChromeFrame.new(@app, {:minimum => 8.0}))
  end

  shared_examples_for "nothing happens" do
    it "should change nothing" do
      @response.body.should eql(simple_html)
    end
  end

  context "not IE:" do
    before do
      @response = @request.get('/')
    end

    it_should_behave_like "nothing happens"
  end

  context "IE:" do

    context "chromeframe installed" do
      before do
        @response = @request.get('/', {'HTTP_USER_AGENT' => 'MSIE 6.0; chromeframe' })
      end

      it "should add meta tag"  do
        @response.body.should include(chrome_frame_meta_tag)
      end
    end

    context "chromeframe not installed" do

      context "but satisfactory IE version installed" do
        before do
          @response = @request.get('/', {'HTTP_USER_AGENT' => 'MSIE 8.0' })
        end

        it_should_behave_like "nothing happens"
      end

      context "but not satisfactory IE version installed" do
        before do
          @response = @request.get('/', {'HTTP_USER_AGENT' => 'MSIE 7.0' })
        end

        it "should suggest chromeframe installation" do
          @response.body.gsub(/\n( )*/, '').should include(chrome_frame_installation_script)
        end
      end
    end
  end
end
	module Rack
	class ChromeFrame

	def initialize(app, options={})
	@app = app
	@options = options
	end

	def call(env)

	if env['HTTP_USER_AGENT'] =~ /MSIE/
	if env['HTTP_USER_AGENT'] =~ /chromeframe/
	status, headers, response = @app.call(env)
	new_body = insert_tag(build_response_body(response))
	new_headers = recalculate_body_length(headers, new_body)
	return [status, new_headers, new_body]
	elsif @options[:minimum].nil? or ie_version(env['HTTP_USER_AGENT']) < @options[:minimum]
	html = <<-HTML
	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
	<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
	<head>
	<meta http-equiv="content-type" content="text/html;charset=UTF-8" />
	<title>You must install chromeframe in order to see this page!</title>
	</head>
	<body>
	<div id="cf-placeholder"></div>
	<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/chrome-frame/1/CFInstall.min.js"></script>
	<script>CFInstall.check({ node: "cf-placeholder" #{', destination: "' + @options[:destination] + '" ' if @options[:destination]}});</script>
	</body>
	</html>
	HTML
	return [200, {'Content-Type' => 'text/html', 'Content-Length' => html.size.to_s}, Rack::Response.new([html])]
	end
	end
	@app.call(env)
	end

	def build_response_body(response)
	response_body = ""
	response.each { \|part\| response_body += part }
	response_body
	end

	def recalculate_body_length(headers, body)
	new_headers = headers
	new_headers["Content-Length"] = body.length.to_s
	new_headers
	end

	def insert_tag(body)
	head = <<-HEAD
	<meta http-equiv="X-UA-Compatible" content="chrome=1">
	HEAD

	body.gsub!('<head>', "<head>\n" + head )
	body
	end

	def ie_version(ua_string)
	ua_string.match(/MSIE (\S+)/)[1].to_f
	end
	end
	end
	require File.dirname(__FILE__) + '/helper'

	describe "Rack::ChromeFrame" do

	before do
	@app = lambda { \|env\| [200, {'Content-Type' => 'text/html'}, simple_html] }
	@request = Rack::MockRequest.new(Rack::ChromeFrame.new(@app, {:minimum => 8.0}))
	end

	shared_examples_for "nothing happens" do
	it "should change nothing" do
	@response.body.should eql(simple_html)
	end
	end

	context "not IE:" do
	before do
	@response = @request.get('/')
	end

	it_should_behave_like "nothing happens"
	end

	context "IE:" do

	context "chromeframe installed" do
	before do
	@response = @request.get('/', {'HTTP_USER_AGENT' => 'MSIE 6.0; chromeframe' })
	end

	it "should add meta tag" do
	@response.body.should include(chrome_frame_meta_tag)
	end
	end

	context "chromeframe not installed" do

	context "but satisfactory IE version installed" do
	before do
	@response = @request.get('/', {'HTTP_USER_AGENT' => 'MSIE 8.0' })
	end

	it_should_behave_like "nothing happens"
	end

	context "but not satisfactory IE version installed" do
	before do
	@response = @request.get('/', {'HTTP_USER_AGENT' => 'MSIE 7.0' })
	end

	it "should suggest chromeframe installation" do
	@response.body.gsub(/\n( )*/, '').should include(chrome_frame_installation_script)
	end
	end
	end
	end
	end