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Diffstat (limited to 'actionview/lib/action_view/helpers/asset_url_helper.rb')
| -rw-r--r-- | actionview/lib/action_view/helpers/asset_url_helper.rb | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/actionview/lib/action_view/helpers/asset_url_helper.rb b/actionview/lib/action_view/helpers/asset_url_helper.rb new file mode 100644 index 0000000000..0b957adb91 --- /dev/null +++ b/actionview/lib/action_view/helpers/asset_url_helper.rb @@ -0,0 +1,355 @@ +require 'zlib' + +module ActionView + # = Action View Asset URL Helpers + module Helpers + # This module provides methods for generating asset paths and + # urls. + # + # image_path("rails.png") + # # => "/assets/rails.png" + # + # image_url("rails.png") + # # => "http://www.example.com/assets/rails.png" + # + # === 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 asset + # server by setting <tt>ActionController::Base.asset_host</tt> in the application + # configuration, typically in <tt>config/environments/production.rb</tt>. + # For example, you'd define <tt>assets.example.com</tt> to be your asset + # host this way, inside the <tt>configure</tt> block of your environment-specific + # configuration files or <tt>config/application.rb</tt>: + # + # config.action_controller.asset_host = "assets.example.com" + # + # Helpers take that into account: + # + # image_tag("rails.png") + # # => <img alt="Rails" src="http://assets.example.com/assets/rails.png" /> + # stylesheet_link_tag("application") + # # => <link href="http://assets.example.com/assets/application.css" media="screen" rel="stylesheet" /> + # + # Browsers typically open at most two simultaneous connections to a single + # host, which means your assets often have to wait for other assets to finish + # downloading. You can alleviate this by using a <tt>%d</tt> wildcard in the + # +asset_host+. For example, "assets%d.example.com". If that wildcard is + # present Rails distributes asset requests among the corresponding four hosts + # "assets0.example.com", ..., "assets3.example.com". With this trick browsers + # will open eight simultaneous connections rather than two. + # + # image_tag("rails.png") + # # => <img alt="Rails" src="http://assets0.example.com/assets/rails.png" /> + # stylesheet_link_tag("application") + # # => <link href="http://assets2.example.com/assets/application.css" media="screen" rel="stylesheet" /> + # + # 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. + # + # Alternatively, you can exert more control over the asset host by setting + # +asset_host+ to a proc like this: + # + # ActionController::Base.asset_host = Proc.new { |source| + # "http://assets#{Digest::MD5.hexdigest(source).to_i(16) % 2 + 1}.example.com" + # } + # image_tag("rails.png") + # # => <img alt="Rails" src="http://assets1.example.com/assets/rails.png" /> + # stylesheet_link_tag("application") + # # => <link href="http://assets2.example.com/assets/application.css" media="screen" rel="stylesheet" /> + # + # The example above generates "http://assets1.example.com" and + # "http://assets2.example.com". This option is useful for example if + # you need fewer/more than four hosts, custom host names, etc. + # + # As you see the proc takes a +source+ parameter. That's a string with the + # absolute path of the asset, for example "/assets/rails.png". + # + # ActionController::Base.asset_host = Proc.new { |source| + # if source.ends_with?('.css') + # "http://stylesheets.example.com" + # else + # "http://assets.example.com" + # end + # } + # image_tag("rails.png") + # # => <img alt="Rails" src="http://assets.example.com/assets/rails.png" /> + # stylesheet_link_tag("application") + # # => <link href="http://stylesheets.example.com/assets/application.css" media="screen" rel="stylesheet" /> + # + # Alternatively you may ask for a second parameter +request+. That one is + # particularly useful for serving assets from an SSL-protected page. The + # example proc below disables asset hosting for HTTPS connections, while + # still sending assets for plain HTTP requests from asset hosts. If you don't + # have SSL certificates for each of the asset hosts this technique allows you + # to avoid warnings in the client about mixed media. + # + # config.action_controller.asset_host = Proc.new { |source, request| + # if request.ssl? + # "#{request.protocol}#{request.host_with_port}" + # else + # "#{request.protocol}assets.example.com" + # end + # } + # + # You can also implement a custom asset host object that responds to +call+ + # and takes either one or two parameters just like the proc. + # + # config.action_controller.asset_host = AssetHostingWithMinimumSsl.new( + # "http://asset%d.example.com", "https://asset1.example.com" + # ) + # + module AssetUrlHelper + URI_REGEXP = %r{^[-a-z]+://|^(?:cid|data):|^//}i + + # Computes the path to asset in public directory. If :type + # options is set, a file extension will be appended and scoped + # to the corresponding public directory. + # + # All other asset *_path helpers delegate through this method. + # + # asset_path "application.js" # => /application.js + # asset_path "application", type: :javascript # => /javascripts/application.js + # asset_path "application", type: :stylesheet # => /stylesheets/application.css + # asset_path "http://www.example.com/js/xmlhr.js" # => http://www.example.com/js/xmlhr.js + def asset_path(source, options = {}) + source = source.to_s + return "" unless source.present? + return source if source =~ URI_REGEXP + + tail, source = source[/([\?#].+)$/], source.sub(/([\?#].+)$/, '') + + if extname = compute_asset_extname(source, options) + source = "#{source}#{extname}" + end + + if source[0] != ?/ + source = compute_asset_path(source, options) + end + + relative_url_root = defined?(config.relative_url_root) && config.relative_url_root + if relative_url_root + source = "#{relative_url_root}#{source}" unless source.starts_with?("#{relative_url_root}/") + end + + if host = compute_asset_host(source, options) + source = "#{host}#{source}" + end + + "#{source}#{tail}" + end + alias_method :path_to_asset, :asset_path # aliased to avoid conflicts with a asset_path named route + + # Computes the full URL to a asset in the public directory. This + # will use +asset_path+ internally, so most of their behaviors + # will be the same. + def asset_url(source, options = {}) + path_to_asset(source, options.merge(:protocol => :request)) + end + alias_method :url_to_asset, :asset_url # aliased to avoid conflicts with an asset_url named route + + ASSET_EXTENSIONS = { + javascript: '.js', + stylesheet: '.css' + } + + # Compute extname to append to asset path. Returns nil if + # nothing should be added. + def compute_asset_extname(source, options = {}) + return if options[:extname] == false + extname = options[:extname] || ASSET_EXTENSIONS[options[:type]] + extname if extname && File.extname(source) != extname + end + + # Maps asset types to public directory. + ASSET_PUBLIC_DIRECTORIES = { + audio: '/audios', + font: '/fonts', + image: '/images', + javascript: '/javascripts', + stylesheet: '/stylesheets', + video: '/videos' + } + + # Computes asset path to public directory. Plugins and + # extensions can override this method to point to custom assets + # or generate digested paths or query strings. + def compute_asset_path(source, options = {}) + dir = ASSET_PUBLIC_DIRECTORIES[options[:type]] || "" + File.join(dir, source) + end + + # Pick an asset host for this source. Returns +nil+ if no host is set, + # the host if no wildcard is set, the host interpolated with the + # numbers 0-3 if it contains <tt>%d</tt> (the number is the source hash mod 4), + # or the value returned from invoking call on an object responding to call + # (proc or otherwise). + def compute_asset_host(source = "", options = {}) + request = self.request if respond_to?(:request) + host = config.asset_host if defined? config.asset_host + host ||= request.base_url if request && options[:protocol] == :request + + if host.respond_to?(:call) + arity = host.respond_to?(:arity) ? host.arity : host.method(:call).arity + args = [source] + args << request if request && (arity > 1 || arity < 0) + host = host.call(*args) + elsif host =~ /%d/ + host = host % (Zlib.crc32(source) % 4) + end + + return unless host + + if host =~ URI_REGEXP + host + else + protocol = options[:protocol] || config.default_asset_host_protocol || (request ? :request : :relative) + case protocol + when :relative + "//#{host}" + when :request + "#{request.protocol}#{host}" + else + "#{protocol}://#{host}" + end + end + end + + # Computes the path to a javascript asset in the public javascripts directory. + # If the +source+ filename has no extension, .js will be appended (except for explicit URIs) + # Full paths from the document root will be passed through. + # Used internally by javascript_include_tag to build the script path. + # + # 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.example.com/js/xmlhr" # => http://www.example.com/js/xmlhr + # javascript_path "http://www.example.com/js/xmlhr.js" # => http://www.example.com/js/xmlhr.js + def javascript_path(source, options = {}) + path_to_asset(source, {type: :javascript}.merge!(options)) + end + alias_method :path_to_javascript, :javascript_path # aliased to avoid conflicts with a javascript_path named route + + # Computes the full URL to a javascript asset in the public javascripts directory. + # This will use +javascript_path+ internally, so most of their behaviors will be the same. + def javascript_url(source, options = {}) + url_to_asset(source, {type: :javascript}.merge!(options)) + end + alias_method :url_to_javascript, :javascript_url # aliased to avoid conflicts with a javascript_url named route + + # Computes the path to a stylesheet asset in the public stylesheets directory. + # If the +source+ filename has no extension, <tt>.css</tt> will be appended (except for explicit URIs). + # Full paths from the document root will be passed through. + # Used internally by +stylesheet_link_tag+ to build the stylesheet path. + # + # 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.example.com/css/style" # => http://www.example.com/css/style + # stylesheet_path "http://www.example.com/css/style.css" # => http://www.example.com/css/style.css + def stylesheet_path(source, options = {}) + path_to_asset(source, {type: :stylesheet}.merge!(options)) + end + alias_method :path_to_stylesheet, :stylesheet_path # aliased to avoid conflicts with a stylesheet_path named route + + # Computes the full URL to a stylesheet asset in the public stylesheets directory. + # This will use +stylesheet_path+ internally, so most of their behaviors will be the same. + def stylesheet_url(source, options = {}) + url_to_asset(source, {type: :stylesheet}.merge!(options)) + end + alias_method :url_to_stylesheet, :stylesheet_url # aliased to avoid conflicts with a stylesheet_url named route + + # Computes the path to an image asset. + # Full paths from the document root will be passed through. + # Used internally by +image_tag+ to build the image path: + # + # image_path("edit") # => "/assets/edit" + # image_path("edit.png") # => "/assets/edit.png" + # image_path("icons/edit.png") # => "/assets/icons/edit.png" + # image_path("/icons/edit.png") # => "/icons/edit.png" + # image_path("http://www.example.com/img/edit.png") # => "http://www.example.com/img/edit.png" + # + # If you have images as application resources this method may conflict with their named routes. + # The alias +path_to_image+ is provided to avoid that. Rails uses the alias internally, and + # plugin authors are encouraged to do so. + def image_path(source, options = {}) + path_to_asset(source, {type: :image}.merge!(options)) + end + alias_method :path_to_image, :image_path # aliased to avoid conflicts with an image_path named route + + # Computes the full URL to an image asset. + # This will use +image_path+ internally, so most of their behaviors will be the same. + def image_url(source, options = {}) + url_to_asset(source, {type: :image}.merge!(options)) + end + alias_method :url_to_image, :image_url # aliased to avoid conflicts with an image_url named route + + # Computes the path to a video asset in the public videos directory. + # Full paths from the document root will be passed through. + # Used internally by +video_tag+ to build the video path. + # + # video_path("hd") # => /videos/hd + # video_path("hd.avi") # => /videos/hd.avi + # video_path("trailers/hd.avi") # => /videos/trailers/hd.avi + # video_path("/trailers/hd.avi") # => /trailers/hd.avi + # video_path("http://www.example.com/vid/hd.avi") # => http://www.example.com/vid/hd.avi + def video_path(source, options = {}) + path_to_asset(source, {type: :video}.merge!(options)) + end + alias_method :path_to_video, :video_path # aliased to avoid conflicts with a video_path named route + + # Computes the full URL to a video asset in the public videos directory. + # This will use +video_path+ internally, so most of their behaviors will be the same. + def video_url(source, options = {}) + url_to_asset(source, {type: :video}.merge!(options)) + end + alias_method :url_to_video, :video_url # aliased to avoid conflicts with an video_url named route + + # Computes the path to an audio asset in the public audios directory. + # Full paths from the document root will be passed through. + # Used internally by +audio_tag+ to build the audio path. + # + # audio_path("horse") # => /audios/horse + # audio_path("horse.wav") # => /audios/horse.wav + # audio_path("sounds/horse.wav") # => /audios/sounds/horse.wav + # audio_path("/sounds/horse.wav") # => /sounds/horse.wav + # audio_path("http://www.example.com/sounds/horse.wav") # => http://www.example.com/sounds/horse.wav + def audio_path(source, options = {}) + path_to_asset(source, {type: :audio}.merge!(options)) + end + alias_method :path_to_audio, :audio_path # aliased to avoid conflicts with an audio_path named route + + # Computes the full URL to an audio asset in the public audios directory. + # This will use +audio_path+ internally, so most of their behaviors will be the same. + def audio_url(source, options = {}) + url_to_asset(source, {type: :audio}.merge!(options)) + end + alias_method :url_to_audio, :audio_url # aliased to avoid conflicts with an audio_url named route + + # Computes the path to a font asset. + # Full paths from the document root will be passed through. + # + # font_path("font") # => /assets/font + # font_path("font.ttf") # => /assets/font.ttf + # font_path("dir/font.ttf") # => /assets/dir/font.ttf + # font_path("/dir/font.ttf") # => /dir/font.ttf + # font_path("http://www.example.com/dir/font.ttf") # => http://www.example.com/dir/font.ttf + def font_path(source, options = {}) + path_to_asset(source, {type: :font}.merge!(options)) + end + alias_method :path_to_font, :font_path # aliased to avoid conflicts with an font_path named route + + # Computes the full URL to a font asset. + # This will use +font_path+ internally, so most of their behaviors will be the same. + def font_url(source, options = {}) + url_to_asset(source, {type: :font}.merge!(options)) + end + alias_method :url_to_font, :font_url # aliased to avoid conflicts with an font_url named route + end + end +end |