class Rack::Static
The Rack::Static middleware intercepts requests for static files (javascript files, images, stylesheets, etc) based on the url prefixes or route mappings passed in the options, and serves them using a Rack::File object. This allows a Rack stack to serve both static and dynamic content.
Examples:
Serve all requests beginning with /media from the “media” folder located in the current directory (ie media/*):
use Rack::Static, :urls => ["/media"]
Serve all requests beginning with /css or /images from the folder “public” in the current directory (ie public/css/* and public/images/*):
use Rack::Static, :urls => ["/css", "/images"], :root => "public"
Serve all requests to / with “index.html” from the folder “public” in the current directory (ie public/index.html):
use Rack::Static, :urls => {"/" => 'index.html'}, :root => 'public'
Serve all requests normally from the folder “public” in the current directory but uses index.html as default route for “/”
use Rack::Static, :urls => [""], :root => 'public', :index => 'index.html'
Set custom HTTP Headers for based on rules:
use Rack::Static, :root => 'public',
:header_rules => [
[rule, {header_field => content, header_field => content}],
[rule, {header_field => content}]
]
Rules for selecting files:
1) All files
Provide the :all symbol
:all => Matches every file
2) Folders
Provide the folder path as a string
'/folder' or '/folder/subfolder' => Matches files in a certain folder
3) File Extensions
Provide the file extensions as an array
['css', 'js'] or %w(css js) => Matches files ending in .css or .js
4) Regular Expressions / Regexp
Provide a regular expression
%r{\.(?:css|js)\z} => Matches files ending in .css or .js
/\.(?:eot|ttf|otf|woff|svg)\z/ => Matches files ending in
the most common web font formats (.eot, .ttf, .otf, .woff, .svg)
Note: This Regexp is available as a shortcut, using the :fonts rule
5) Font Shortcut
Provide the :fonts symbol
:fonts => Uses the Regexp rule stated right above to match all common web font endings
Rule Ordering:
Rules are applied in the order that they are provided.
List rather general rules above special ones.
Complete example use case including HTTP header rules:
use Rack::Static, :root => 'public',
:header_rules => [
# Cache all static files in public caches (e.g. Rack::Cache)
# as well as in the browser
[:all, {'Cache-Control' => 'public, max-age=31536000'}],
# Provide web fonts with cross-origin access-control-headers
# Firefox requires this when serving assets using a Content Delivery Network
[:fonts, {'Access-Control-Allow-Origin' => '*'}]
]
Public Class Methods
# File lib/rack/static.rb, line 83 def initialize(app, options={}) @app = app @urls = options[:urls] || ["/favicon.ico"] @index = options[:index] root = options[:root] || Dir.pwd # HTTP Headers @header_rules = options[:header_rules] || [] # Allow for legacy :cache_control option while prioritizing global header_rules setting @header_rules.insert(0, [:all, {'Cache-Control' => options[:cache_control]}]) if options[:cache_control] @file_server = Rack::File.new(root) end
Public Instance Methods
Convert HTTP header rules to HTTP headers
# File lib/rack/static.rb, line 129 def applicable_rules(path) @header_rules.find_all do |rule, new_headers| case rule when :all true when :fonts path =~ /\.(?:ttf|otf|eot|woff|svg)\z/ when String path = ::Rack::Utils.unescape(path) path.start_with?(rule) || path.start_with?('/' + rule) when Array path =~ /\.(#{rule.join('|')})\z/ when Regexp path =~ rule else false end end end
# File lib/rack/static.rb, line 109 def call(env) path = env[PATH_INFO] if can_serve(path) env["PATH_INFO"] = (path =~ /\/$/ ? path + @index : @urls[path]) if overwrite_file_path(path) path = env["PATH_INFO"] response = @file_server.call(env) headers = response[1] applicable_rules(path).each do |rule, new_headers| new_headers.each { |field, content| headers[field] = content } end response else @app.call(env) end end
# File lib/rack/static.rb, line 105 def can_serve(path) route_file(path) || overwrite_file_path(path) end
# File lib/rack/static.rb, line 97 def overwrite_file_path(path) @urls.kind_of?(Hash) && @urls.key?(path) || @index && path =~ /\/$/ end
# File lib/rack/static.rb, line 101 def route_file(path) @urls.kind_of?(Array) && @urls.any? { |url| path.index(url) == 0 } end