require 'cgi'
require 'action_view/helpers/url_helper'
require 'action_view/helpers/tag_helper'
module ActionView
module Helpers #:nodoc:
# This module provides methods for generating HTML that links views to assets such
# as images, javascripts, stylesheets, and feeds. These methods do not verify
# the assets exist before linking to them.
#
# === Using asset hosts
# By default, Rails links to these assets on the current host in the public
# folder, but you can direct Rails to link to assets from a dedicated assets server by
# setting ActionController::Base.asset_host in your environment.rb. For example,
# let's say your asset host is assets.example.com.
#
# ActionController::Base.asset_host = "assets.example.com"
# image_tag("rails.png")
# => <img src="http://assets.example.com/images/rails.png" alt="Rails" />
# stylesheet_include_tag("application")
# => <link href="http://assets.example.com/stylesheets/application.css" media="screen" rel="stylesheet" type="text/css" />
#
# This is useful since browsers typically open at most two connections to a single host,
# which means your assets often wait in single file for their turn to load. You can
# alleviate this by using a %d wildcard in <tt>asset_host</tt> (for example, "assets%d.example.com")
# to automatically distribute asset requests among four hosts (e.g., assets0.example.com through assets3.example.com)
# so browsers will open eight connections rather than two.
#
# image_tag("rails.png")
# => <img src="http://assets0.example.com/images/rails.png" alt="Rails" />
# stylesheet_include_tag("application")
# => <link href="http://assets3.example.com/stylesheets/application.css" media="screen" rel="stylesheet" type="text/css" />
#
# To do this, you can either setup four actual hosts, or you can use wildcard DNS to CNAME
# the wildcard to a single asset host. You can read more about setting up your DNS CNAME records from
# your ISP.
#
# Note: This is purely a browser performance optimization and is not meant
# for server load balancing. See http://www.die.net/musings/page_load_time/
# for background.
#
# === Using asset timestamps
#
# By default, Rails will prepend all asset paths with that asset's timestamp. This allows you to set a cache-expiration date for the
# asset far into the future, but still be able to instantly invalidate it by simply updating the file (and hence updating the timestamp,
# which then updates the URL as the timestamp is part of that, which in turn busts the cache).
#
# It's the responsibility of the web server you use to set the far-future expiration date on cache assets that you need to take
# advantage of this feature. Here's an example for Apache:
#
# # Asset Expiration
# ExpiresActive On
# <FilesMatch "\.(ico|gif|jpe?g|png|js|css)$">
# ExpiresDefault "access plus 1 year"
# </FilesMatch>
#
# Also note that in order for this to work, all your application servers must return the same timestamps. This means that they must
# have their clocks synchronized. If one of them drift out of synch, you'll see different timestamps at random and the cache won't
# work. Which means that the browser will request the same assets over and over again even thought they didn't change. You can use
# something like Live HTTP Headers for Firefox to verify that the cache is indeed working (and that the assets are not being
# requested over and over).
module AssetTagHelper
ASSETS_DIR = defined?(RAILS_ROOT) ? "#{RAILS_ROOT}/public" : "public"
JAVASCRIPTS_DIR = "#{ASSETS_DIR}/javascripts"
STYLESHEETS_DIR = "#{ASSETS_DIR}/stylesheets"
# Returns a link tag that browsers and news readers can use to auto-detect
# an RSS or ATOM feed. The +type+ can either be <tt>:rss</tt> (default) or
# <tt>:atom</tt>. Control the link options in url_for format using the
# +url_options+. You can modify the LINK tag itself in +tag_options+.
#
# ==== Options:
# * <tt>:rel</tt> - Specify the relation of this link, defaults to "alternate"
# * <tt>:type</tt> - Override the auto-generated mime type
# * <tt>:title</tt> - Specify the title of the link, defaults to the +type+
#
# ==== Examples
# auto_discovery_link_tag # =>
# <link rel="alternate" type="application/rss+xml" title="RSS" href="http://www.currenthost.com/controller/action" />
# auto_discovery_link_tag(:atom) # =>
# <link rel="alternate" type="application/atom+xml" title="ATOM" href="http://www.currenthost.com/controller/action" />
# auto_discovery_link_tag(:rss, {:action => "feed"}) # =>
# <link rel="alternate" type="application/rss+xml" title="RSS" href="http://www.currenthost.com/controller/feed" />
# auto_discovery_link_tag(:rss, {:action => "feed"}, {:title => "My RSS"}) # =>
# <link rel="alternate" type="application/rss+xml" title="My RSS" href="http://www.currenthost.com/controller/feed" />
# auto_discovery_link_tag(:rss, {:controller => "news", :action => "feed"}) # =>
# <link rel="alternate" type="application/rss+xml" title="RSS" href="http://www.currenthost.com/news/feed" />
# auto_discovery_link_tag(:rss, "http://www.example.com/feed.rss", {:title => "Example RSS"}) # =>
# <link rel="alternate" type="application/rss+xml" title="Example RSS" href="http://www.example.com/feed" />
def auto_discovery_link_tag(type = :rss, url_options = {}, tag_options = {})
tag(
"link",
"rel" => tag_options[:rel] || "alternate",
"type" => tag_options[:type] || Mime::Type.lookup_by_extension(type.to_s).to_s,
"title" => tag_options[:title] || type.to_s.upcase,
"href" => url_options.is_a?(Hash) ? url_for(url_options.merge(:only_path => false)) : url_options
)
end
# Computes the path to a javascript asset in the public javascripts directory.
# If the +source+ filename has no extension, .js will be appended.
# Full paths from the document root will be passed through.
# Used internally by javascript_include_tag to build the script path.
#
# ==== Examples
# javascript_path "xmlhr" # => /javascripts/xmlhr.js
# javascript_path "dir/xmlhr.js" # => /javascripts/dir/xmlhr.js
# javascript_path "/dir/xmlhr" # => /dir/xmlhr.js
# javascript_path "http://www.railsapplication.com/js/xmlhr" # => http://www.railsapplication.com/js/xmlhr.js
# javascript_path "http://www.railsapplication.com/js/xmlhr.js" # => http://www.railsapplication.com/js/xmlhr.js
def javascript_path(source)
compute_public_path(source, 'javascripts', 'js')
end
alias_method :path_to_javascript, :javascript_path # aliased to avoid conflicts with a javascript_path named route
JAVASCRIPT_DEFAULT_SOURCES = ['prototype', 'effects', 'dragdrop', 'controls'] unless const_defined?(:JAVASCRIPT_DEFAULT_SOURCES)
@@javascript_default_sources = JAVASCRIPT_DEFAULT_SOURCES.dup
# Returns an html script tag for each of the +sources+ provided. You
# can pass in the filename (.js extension is optional) of javascript files
# that exist in your public/javascripts directory for inclusion into the
# current page or you can pass the full path relative to your document
# root. To include the Prototype and Scriptaculous javascript libraries in
# your application, pass <tt>:defaults</tt> as the source. When using
# :defaults, if an <tt>application.js</tt> file exists in your public
# javascripts directory, it will be included as well. You can modify the
# html attributes of the script tag by passing a hash as the last argument.
#
# ==== Examples
# javascript_include_tag "xmlhr" # =>
# <script type="text/javascript" src="/javascripts/xmlhr.js"></script>
#
# javascript_include_tag "xmlhr.js" # =>
# <script type="text/javascript" src="/javascripts/xmlhr.js"></script>
#
# javascript_include_tag "common.javascript", "/elsewhere/cools" # =>
# <script type="text/javascript" src="/javascripts/common.javascript"></script>
# <script type="text/javascript" src="/elsewhere/cools.js"></script>
#
# javascript_include_tag "http://www.railsapplication.com/xmlhr" # =>
# <script type="text/javascript" src="http://www.railsapplication.com/xmlhr.js"></script>
#
# javascript_include_tag "http://www.railsapplication.com/xmlhr.js" # =>
# <script type="text/javascript" src="http://www.railsapplication.com/xmlhr.js"></script>
#
# javascript_include_tag :defaults # =>
# <script type="text/javascript" src="/javascripts/prototype.js"></script>
# <script type="text/javascript" src="/javascripts/effects.js"></script>
# ...
# <script type="text/javascript" src="/javascripts/application.js"></script>
#
# * = The application.js file is only referenced if it exists
#
# Though it's not really recommended practice, if you need to extend the default JavaScript set for any reason
# (e.g., you're going to be using a certain .js file in every action), then take a look at the register_javascript_include_default method.
#
# You can also include all javascripts in the javascripts directory using <tt>:all</tt> as the source:
#
# javascript_include_tag :all # =>
# <script type="text/javascript" src="/javascripts/prototype.js"></script>
# <script type="text/javascript" src="/javascripts/effects.js"></script>
# ...
# <script type="text/javascript" src="/javascripts/application.js"></script>
# <script type="text/javascript" src="/javascripts/shop.js"></script>
# <script type="text/javascript" src="/javascripts/checkout.js"></script>
#
# Note that the default javascript files will be included first. So Prototype and Scriptaculous are available to
# all subsequently included files.
#
# == Caching multiple javascripts into one
#
# You can also cache multiple javascripts into one file, which requires less HTTP connections to download and can better be
# compressed by gzip (leading to faster transfers). Caching will only happen if ActionController::Base.perform_caching
# is set to <tt>true</tt> (which is the case by default for the Rails production environment, but not for the development
# environment).
#
# ==== Examples
# javascript_include_tag :all, :cache => true # when ActionController::Base.perform_caching is false =>
# <script type="text/javascript" src="/javascripts/prototype.js"></script>
# <script type="text/javascript" src="/javascripts/effects.js"></script>
# ...
# <script type="text/javascript" src="/javascripts/application.js"></script>
# <script type="text/javascript" src="/javascripts/shop.js"></script>
# <script type="text/javascript" src="/javascripts/checkout.js"></script>
#
# javascript_include_tag :all, :cache => true # when ActionController::Base.perform_caching is true =>
# <script type="text/javascript" src="/javascripts/all.js"></script>
#
# javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when ActionController::Base.perform_caching is false =>
# <script type="text/javascript" src="/javascripts/prototype.js"></script>
# <script type="text/javascript" src="/javascripts/cart.js"></script>
# <script type="text/javascript" src="/javascripts/checkout.js"></script>
#
# javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when ActionController::Base.perform_caching is false =>
# <script type="text/javascript" src="/javascripts/shop.js"></script>
def javascript_include_tag(*sources)
options = sources.extract_options!.stringify_keys
cache = options.delete("cache")
if ActionController::Base.perform_caching && cache
joined_javascript_name = (cache == true ? "all" : cache) + ".js"
joined_javascript_path = File.join(JAVASCRIPTS_DIR, joined_javascript_name)
if !file_exist?(joined_javascript_path)
File.open(joined_javascript_path, "w+") do |cache|
javascript_paths = expand_javascript_sources(sources).collect do |source|
compute_public_path(source, 'javascripts', 'js', false)
end
cache.write(join_asset_file_contents(javascript_paths))
end
end
content_tag("script", "", {
"type" => Mime::JS, "src" => path_to_javascript(joined_javascript_name)
}.merge(options))
else
expand_javascript_sources(sources).collect do |source|
content_tag("script", "", { "type" => Mime::JS, "src" => path_to_javascript(source) }.merge(options))
end.join("\n")
end
end
# Register one or more additional JavaScript files to be included when
# <tt>javascript_include_tag :defaults</tt> is called. This method is
# typically intended to be called from plugin initialization to register additional
# .js files that the plugin installed in <tt>public/javascripts</tt>.
def self.register_javascript_include_default(*sources)
@@javascript_default_sources.concat(sources)
end
def self.reset_javascript_include_default #:nodoc:
@@javascript_default_sources = JAVASCRIPT_DEFAULT_SOURCES.dup
end
# Computes the path to a stylesheet asset in the public stylesheets directory.
# If the +source+ filename has no extension, .css will be appended.
# Full paths from the document root will be passed through.
# Used internally by stylesheet_link_tag to build the stylesheet path.
#
# ==== Examples
# stylesheet_path "style" # => /stylesheets/style.css
# stylesheet_path "dir/style.css" # => /stylesheets/dir/style.css
# stylesheet_path "/dir/style.css" # => /dir/style.css
# stylesheet_path "http://www.railsapplication.com/css/style" # => http://www.railsapplication.com/css/style.css
# stylesheet_path "http://www.railsapplication.com/css/style.js" # => http://www.railsapplication.com/css/style.css
def stylesheet_path(source)
compute_public_path(source, 'stylesheets', 'css')
end
alias_method :path_to_stylesheet, :stylesheet_path # aliased to avoid conflicts with a stylesheet_path named route
# Returns a stylesheet link tag for the sources specified as arguments. If
# you don't specify an extension, .css will be appended automatically.
# You can modify the link attributes by passing a hash as the last argument.
#
# ==== Examples
# stylesheet_link_tag "style" # =>
# <link href="/stylesheets/style.css" media="screen" rel="stylesheet" type="text/css" />
#
# stylesheet_link_tag "style.css" # =>
# <link href="/stylesheets/style.css" media="screen" rel="stylesheet" type="text/css" />
#
# stylesheet_link_tag "http://www.railsapplication.com/style.css" # =>
# <link href="http://www.railsapplication.com/style.css" media="screen" rel="stylesheet" type="text/css" />
#
# stylesheet_link_tag "style", :media => "all" # =>
# <link href="/stylesheets/style.css" media="all" rel="stylesheet" type="text/css" />
#
# stylesheet_link_tag "style", :media => "print" # =>
# <link href="/stylesheets/style.css" media="print" rel="stylesheet" type="text/css" />
#
# stylesheet_link_tag "random.styles", "/css/stylish" # =>
# <link href="/stylesheets/random.styles" media="screen" rel="stylesheet" type="text/css" />
# <link href="/css/stylish.css" media="screen" rel="stylesheet" type="text/css" />
#
# You can also include all styles in the stylesheet directory using :all as the source:
#
# stylesheet_link_tag :all # =>
# <link href="/stylesheets/style1.css" media="screen" rel="stylesheet" type="text/css" />
# <link href="/stylesheets/styleB.css" media="screen" rel="stylesheet" type="text/css" />
# <link href="/stylesheets/styleX2.css" media="screen" rel="stylesheet" type="text/css" />
#
# == Caching multiple stylesheets into one
#
# You can also cache multiple stylesheets into one file, which requires less HTTP connections and can better be
# compressed by gzip (leading to faster transfers). Caching will only happen if ActionController::Base.perform_caching
# is set to true (which is the case by default for the Rails production environment, but not for the development
# environment). Examples:
#
# ==== Examples
# stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is false =>
# <link href="/stylesheets/style1.css" media="screen" rel="stylesheet" type="text/css" />
# <link href="/stylesheets/styleB.css" media="screen" rel="stylesheet" type="text/css" />
# <link href="/stylesheets/styleX2.css" media="screen" rel="stylesheet" type="text/css" />
#
# stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is true =>
# <link href="/stylesheets/all.css" media="screen" rel="stylesheet" type="text/css" />
#
# stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when ActionController::Base.perform_caching is false =>
# <link href="/stylesheets/shop.css" media="screen" rel="stylesheet" type="text/css" />
# <link href="/stylesheets/cart.css" media="screen" rel="stylesheet" type="text/css" />
# <link href="/stylesheets/checkout.css" media="screen" rel="stylesheet" type="text/css" />
#
# stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when ActionController::Base.perform_caching is true =>
# <link href="/stylesheets/payment.css" media="screen" rel="stylesheet" type="text/css" />
def stylesheet_link_tag(*sources)
options = sources.extract_options!.stringify_keys
cache = options.delete("cache")
if ActionController::Base.perform_caching && cache
joined_stylesheet_name = (cache == true ? "all" : cache) + ".css"
joined_stylesheet_path = File.join(STYLESHEETS_DIR, joined_stylesheet_name)
if !file_exist?(joined_stylesheet_path)
File.open(joined_stylesheet_path, "w+") do |cache|
stylesheet_paths = expand_stylesheet_sources(sources).collect do |source|
compute_public_path(source, 'stylesheets', 'css', false)
end
cache.write(join_asset_file_contents(stylesheet_paths))
end
end
tag("link", {
"rel" => "stylesheet", "type" => Mime::CSS, "media" => "screen",
"href" => html_escape(path_to_stylesheet(joined_stylesheet_name))
}.merge(options), false, false)
else
options.delete("cache")
expand_stylesheet_sources(sources).collect do |source|
tag("link", {
"rel" => "stylesheet", "type" => Mime::CSS, "media" => "screen", "href" => html_escape(path_to_stylesheet(source))
}.merge(options), false, false)
end.join("\n")
end
end
# Computes the path to an image asset in the public images directory.
# Full paths from the document root will be passed through.
# Used internally by image_tag to build the image path.
#
# ==== Examples
# image_path("edit") # => /images/edit
# image_path("edit.png") # => /images/edit.png
# image_path("icons/edit.png") # => /images/icons/edit.png
# image_path("/icons/edit.png") # => /icons/edit.png
# image_path("http://www.railsapplication.com/img/edit.png") # => http://www.railsapplication.com/img/edit.png
def image_path(source)
compute_public_path(source, 'images')
end
alias_method :path_to_image, :image_path # aliased to avoid conflicts with an image_path named route
# Returns an html image tag for the +source+. The +source+ can be a full
# path or a file that exists in your public images directory.
#
# ==== Options
# You can add HTML attributes using the +options+. The +options+ supports
# three additional keys for convienence and conformance:
#
# * <tt>:alt</tt> - If no alt text is given, the file name part of the
# +source+ is used (capitalized and without the extension)
# * <tt>:size</tt> - Supplied as "{Width}x{Height}", so "30x45" becomes
# width="30" and height="45". <tt>:size</tt> will be ignored if the
# value is not in the correct format.
# * <tt>:mouseover</tt> - Set an alternate image to be used when the onmouseover
# event is fired, and sets the original image to be replaced onmouseout.
# This can be used to implement an easy image toggle that fires on onmouseover.
#
# ==== Examples
# image_tag("icon") # =>
# <img src="/images/icon" alt="Icon" />
# image_tag("icon.png") # =>
# <img src="/images/icon.png" alt="Icon" />
# image_tag("icon.png", :size => "16x10", :alt => "Edit Entry") # =>
# <img src="/images/icon.png" width="16" height="10" alt="Edit Entry" />
# image_tag("/icons/icon.gif", :size => "16x16") # =>
# <img src="/icons/icon.gif" width="16" height="16" alt="Icon" />
# image_tag("/icons/icon.gif", :height => '32', :width => '32') # =>
# <img alt="Icon" height="32" src="/icons/icon.gif" width="32" />
# image_tag("/icons/icon.gif", :class => "menu_icon") # =>
# <img alt="Icon" class="menu_icon" src="/icons/icon.gif" />
# image_tag("mouse.png", :mouseover => "/images/mouse_over.png") # =>
# <img src="/images/mouse.png" onmouseover="this.src='/images/mouse_over.png'" onmouseout="this.src='/images/mouse.png'" alt="Mouse" />
# image_tag("mouse.png", :mouseover => image_path("mouse_over.png")) # =>
# <img src="/images/mouse.png" onmouseover="this.src='/images/mouse_over.png'" onmouseout="this.src='/images/mouse.png'" alt="Mouse" />
def image_tag(source, options = {})
options.symbolize_keys!
options[:src] = path_to_image(source)
options[:alt] ||= File.basename(options[:src], '.*').split('.').first.capitalize
if size = options.delete(:size)
options[:width], options[:height] = size.split("x") if size =~ %r{^\d+x\d+$}
end
if mouseover = options.delete(:mouseover)
options[:onmouseover] = "this.src='#{image_path(mouseover)}'"
options[:onmouseout] = "this.src='#{image_path(options[:src])}'"
end
tag("img", options)
end
private
def file_exist?(path)
@@file_exist_cache ||= {}
if !(@@file_exist_cache[path] ||= File.exist?(path))
@@file_exist_cache[path] = true
false
else
true
end
end
# Add the .ext if not present. Return full URLs otherwise untouched.
# Prefix with /dir/ if lacking a leading /. Account for relative URL
# roots. Rewrite the asset path for cache-busting asset ids. Include
# a single or wildcarded asset host, if configured, with the correct
# request protocol.
def compute_public_path(source, dir, ext = nil, include_host = true)
has_request = @controller.respond_to?(:request)
cache_key =
if has_request
[ @controller.request.protocol,
ActionController::Base.asset_host,
@controller.request.relative_url_root,
dir, source, ext, include_host ].join
else
[ ActionController::Base.asset_host,
dir, source, ext, include_host ].join
end
ActionView::Base.computed_public_paths[cache_key] ||=
begin
source += ".#{ext}" if File.extname(source).blank? && ext
if source =~ %r{^[-a-z]+://}
source
else
source = "/#{dir}/#{source}" unless source[0] == ?/
if has_request
source = "#{@controller.request.relative_url_root}#{source}"
end
rewrite_asset_path!(source)
if include_host
host = compute_asset_host(source)
if has_request && !host.blank? && host !~ %r{^[-a-z]+://}
host = "#{@controller.request.protocol}#{host}"
end
"#{host}#{source}"
else
source
end
end
end
end
# Pick an asset host for this source. Returns nil if no host is set,
# the host if no wildcard is set, or the host interpolated with the
# numbers 0-3 if it contains %d. The number is the source hash mod 4.
def compute_asset_host(source)
if host = ActionController::Base.asset_host
host % (source.hash % 4)
end
end
# Use the RAILS_ASSET_ID environment variable or the source's
# modification time as its cache-busting asset id.
def rails_asset_id(source)
if asset_id = ENV["RAILS_ASSET_ID"]
asset_id
else
path = File.join(ASSETS_DIR, source)
if File.exist?(path)
File.mtime(path).to_i.to_s
else
''
end
end
end
# Break out the asset path rewrite so you wish to put the asset id
# someplace other than the query string.
def rewrite_asset_path!(source)
asset_id = rails_asset_id(source)
source << "?#{asset_id}" if !asset_id.blank?
end
def expand_javascript_sources(sources)
case
when sources.include?(:all)
all_javascript_files = Dir[File.join(JAVASCRIPTS_DIR, '*.js')].collect { |file| File.basename(file).split(".", 0).first }.sort
sources = ((@@javascript_default_sources.dup & all_javascript_files) + all_javascript_files).uniq
when sources.include?(:defaults)
sources = sources[0..(sources.index(:defaults))] +
@@javascript_default_sources.dup +
sources[(sources.index(:defaults) + 1)..sources.length]
sources.delete(:defaults)
sources << "application" if file_exist?(File.join(JAVASCRIPTS_DIR, "application.js"))
end
sources
end
def expand_stylesheet_sources(sources)
if sources.first == :all
@@all_stylesheet_sources ||= Dir[File.join(STYLESHEETS_DIR, '*.css')].collect { |file| File.basename(file).split(".", 1).first }.sort
else
sources
end
end
def join_asset_file_contents(paths)
paths.collect { |path| File.read(File.join(ASSETS_DIR, path.split("?").first)) }.join("\n\n")
end
end
end
end
