Class: Rack::JQuery

Inherits:
Object
  • Object
show all
Includes:
Helpers
Defined in:
lib/rack/jquery.rb,
lib/rack/jquery/version.rb

Overview

jQuery CDN script tags and fallback in one neat package.

Constant Summary collapse

JQUERY_FILE_NAME = 
"jquery-#{JQUERY_VERSION}.min.js"
MEDIA_TEMPLE =

Script tags for the Media Temple CDN

"<script src='http://code.jquery.com/#{JQUERY_FILE_NAME}'></script>"
GOOGLE =

Script tags for the Google CDN

"<script src='//ajax.googleapis.com/ajax/libs/jquery/#{JQUERY_VERSION}/jquery.min.js'></script>"
MICROSOFT =

Script tags for the Microsoft CDN

"<script src='//ajax.aspnetcdn.com/ajax/jQuery/#{JQUERY_FILE_NAME}'></script>"
CLOUDFLARE =

Script tags for the Cloudflare CDN

"<script src='//cdnjs.cloudflare.com/ajax/libs/jquery/#{JQUERY_VERSION}/jquery.min.js'></script>"
FALLBACK =

This javascript checks if the jQuery object has loaded. If not, that most likely means the CDN is unreachable, so it uses the local minified jQuery.

<<STR
<script type="text/javascript">
  if (typeof jQuery == 'undefined') {
    document.write(unescape("%3Cscript src='/js/#{JQUERY_FILE_NAME}' type='text/javascript'%3E%3C/script%3E"))
  };
</script>
STR
DEFAULT_OPTIONS =

Default options hash for the middleware.

{
  :http_path => "/js"
}
VERSION =

the version of this library

"1.4.0"
JQUERY_VERSION =

the version of jQuery it supports.

"2.0.0"
JQUERY_VERSION_DATE =
TODO:

remember to change Last-Modified with each release!

This is the release date of the jQuery file, it makes an easy “Last-Modified” date for setting the headers around caching.

"Thu, 18 Apr 2013 00:00:00 GMT"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

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

Returns a new instance of JQuery.

Examples:

# The default:
use Rack::JQuery
# With a different route to the fallback:
use Rack::JQuery, :http_path => "/assets/js"

Options Hash (options):

  • :http_path (String) —

    If you wish the jQuery fallback route to be “/js/jquery-1.9.1.min.js” (or whichever version this is at) then do nothing, that’s the default. If you want the path to be “/assets/javascripts/jquery-1.9.1.min.js” then pass in ‘:http_path => “/assets/javascripts”.



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# File 'lib/rack/jquery.rb', line 66

def initialize( app, options={} )
  @app, @options  = app, DEFAULT_OPTIONS.merge(options)
  @http_path_to_jquery = ::File.join @options[:http_path], JQUERY_FILE_NAME
end

Class Method Details

.cdn(organisation = :media_temple) ⇒ String 



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# File 'lib/rack/jquery.rb', line 35

def self.cdn( organisation=:media_temple  )
  script = case organisation
    when :media_temple
      MEDIA_TEMPLE
    when :microsoft
      MICROSOFT
    when :cloudflare
      CLOUDFLARE
    when :google
      GOOGLE
    else
      MEDIA_TEMPLE
  end
  "#{script}\n#{FALLBACK}"
end

Instance Method Details

#_call(env) ⇒ Object

For thread safety



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# File 'lib/rack/jquery.rb', line 80

def _call( env )
  request = Rack::Request.new(env.dup)
  if request.path_info == @http_path_to_jquery
    response = Rack::Response.new
    # for caching
    response.headers.merge! caching_headers( JQUERY_FILE_NAME, JQUERY_VERSION_DATE)

    # There's no need to test if the IF_MODIFIED_SINCE against the release date because the header will only be passed if the file was previously accessed by the requester, and the file is never updated. If it is updated then it is accessed by a different path.
    if request.env['HTTP_IF_MODIFIED_SINCE']
      response.status = 304
    else
      response.status = 200
      response.write ::File.read( ::File.expand_path "../../../vendor/assets/javascripts/#{JQUERY_FILE_NAME}", __FILE__)
    end
    response.finish
  else
    @app.call(env)
  end
end

#call(env) ⇒ Object 



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# File 'lib/rack/jquery.rb', line 73

def call( env )
  dup._call env
end