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") # => Rails # stylesheet_include_tag("application") # => # # 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 asset_host (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") # => Rails # stylesheet_include_tag("application") # => # # 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. 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 :rss (default) or # :atom. Control the link options in url_for format using the # +url_options+. You can modify the LINK tag itself in +tag_options+. # # ==== Options: # * :rel - Specify the relation of this link, defaults to "alternate" # * :type - Override the auto-generated mime type # * :title - Specify the title of the link, defaults to the +type+ # # ==== Examples # auto_discovery_link_tag # => # # auto_discovery_link_tag(:atom) # => # # auto_discovery_link_tag(:rss, {:action => "feed"}) # => # # auto_discovery_link_tag(:rss, {:action => "feed"}, {:title => "My RSS"}) # => # # auto_discovery_link_tag(:rss, {:controller => "news", :action => "feed"}) # => # # auto_discovery_link_tag(:rss, "http://www.example.com/feed.rss", {:title => "Example RSS"}) # => # 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 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 :defaults as the source. When using # :defaults, if an application.js 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" # => # # # javascript_include_tag "xmlhr.js" # => # # # javascript_include_tag "common.javascript", "/elsewhere/cools" # => # # # # javascript_include_tag "http://www.railsapplication.com/xmlhr" # => # # # javascript_include_tag "http://www.railsapplication.com/xmlhr.js" # => # # # javascript_include_tag :defaults # => # # # ... # # # * = 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 :all as the source: # # javascript_include_tag :all # => # # # ... # # # # # 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 true (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 => # # # ... # # # # # javascript_include_tag :all, :cache => true # when ActionController::Base.perform_caching is true => # # # javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when ActionController::Base.perform_caching is false => # # # # # javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when ActionController::Base.perform_caching is false => # def javascript_include_tag(*sources) options = sources.last.is_a?(Hash) ? sources.pop.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.exists?(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" => javascript_path(joined_javascript_name) }.merge(options)) else expand_javascript_sources(sources).collect do |source| content_tag("script", "", { "type" => Mime::JS, "src" => javascript_path(source) }.merge(options)) end.join("\n") end end # Register one or more additional JavaScript files to be included when # javascript_include_tag :defaults is called. This method is # typically intended to be called from plugin initialization to register additional # .js files that the plugin installed in public/javascripts. 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 # 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" # => # # # stylesheet_link_tag "style.css" # => # # # stylesheet_link_tag "http://www.railsapplication.com/style.css" # => # # # stylesheet_link_tag "style", :media => "all" # => # # # stylesheet_link_tag "style", :media => "print" # => # # # stylesheet_link_tag "random.styles", "/css/stylish" # => # # # # You can also include all styles in the stylesheet directory using :all as the source: # # stylesheet_link_tag :all # => # # # # # == 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 => # # # # # stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is true => # # # stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when ActionController::Base.perform_caching is false => # # # # # stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when ActionController::Base.perform_caching is true => # def stylesheet_link_tag(*sources) options = sources.last.is_a?(Hash) ? sources.pop.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.exists?(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" => stylesheet_path(joined_stylesheet_name) }.merge(options)) else options.delete("cache") expand_stylesheet_sources(sources).collect do |source| tag("link", { "rel" => "Stylesheet", "type" => Mime::CSS, "media" => "screen", "href" => stylesheet_path(source) }.merge(options)) 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. Passing # a filename without an extension is deprecated. # # ==== Examples # 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) unless (source.split("/").last || source).include?(".") || source.blank? ActiveSupport::Deprecation.warn( "You've called image_path with a source that doesn't include an extension. " + "In Rails 2.0, that will not result in .png automatically being appended. " + "So you should call image_path('#{source}.png') instead", caller ) end compute_public_path(source, 'images', 'png') end # 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. Note that # specifying a filename without the extension is now deprecated in Rails. # # ==== Options # You can add HTML attributes using the +options+. The +options+ supports # two additional keys for convienence and conformance: # # * :alt - If no alt text is given, the file name part of the # +source+ is used (capitalized and without the extension) # * :size - Supplied as "{Width}x{Height}", so "30x45" becomes # width="30" and height="45". :size will be ignored if the # value is not in the correct format. # # ==== Examples # image_tag("icon.png") # => # Icon # image_tag("icon.png", :size => "16x10", :alt => "Edit Entry") # => # Edit Entry # image_tag("/icons/icon.gif", :size => "16x16") # => # Icon # image_tag("/icons/icon.gif", :height => '32', :width => '32') # => # Icon # image_tag("/icons/icon.gif", :class => "menu_icon") # => # Icon def image_tag(source, options = {}) options.symbolize_keys! options[:src] = image_path(source) options[:alt] ||= File.basename(options[:src], '.*').split('.').first.capitalize if options[:size] options[:width], options[:height] = options[:size].split("x") if options[:size] =~ %r{^\d+x\d+$} options.delete(:size) end tag("img", options) end private # 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, include_host = true) source += ".#{ext}" if File.extname(source).blank? if source =~ %r{^[-a-z]+://} source else source = "/#{dir}/#{source}" unless source[0] == ?/ source = "#{@controller.request.relative_url_root}#{source}" rewrite_asset_path!(source) if include_host host = compute_asset_host(source) unless host.blank? or host =~ %r{^[-a-z]+://} host = "#{@controller.request.protocol}#{host}" end "#{host}#{source}" else source 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) ENV["RAILS_ASSET_ID"] || File.mtime(File.join(ASSETS_DIR, source)).to_i.to_s rescue "" 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.exists?(File.join(JAVASCRIPTS_DIR, "application.js")) end sources end def expand_stylesheet_sources(sources) if sources.first == :all 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